eps steering rack.... delvin into the deep!

[britlude]

My steering rack was making the typical knocking noise often reported on NSXPrime, so when I did the front ball joints, I swapped in my spare rack, and put it on the shelf for later. After over 150k miles, it deserved a rest!

At the last MOT the replacement rack was showing an early indication of a problem, no loose play, but a slight lag in assist, so my spare rack was taken off the shelf and investigations begin!

https://farm8.staticflickr.com/7916/47264806641_f4f7ed9cd4_c.jpg (https://flic.kr/p/2f1Cukk)IMG_20190302_161729 (https://flic.kr/p/2f1Cukk) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


If you remember, the motor power connections were a tad crusty, probably using the same nuts as fitted to the exhaust system!

https://farm8.staticflickr.com/7904/40300216343_1abe908f72_c.jpg (https://flic.kr/p/24pc9hg)IMG_20190302_161818 (https://flic.kr/p/24pc9hg) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


A quick saw cut and tap with a chisel….

https://farm8.staticflickr.com/7911/40300215083_4a6713cfed_c.jpg (https://flic.kr/p/24pc8Ux)IMG_20190302_161933 (https://flic.kr/p/24pc8Ux) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


Under these were 2 more special nuts, fortunately these came out quite easily!

https://farm8.staticflickr.com/7843/40300215793_8e505fd59b_c.jpg (https://flic.kr/p/24pc97M)IMG_20190302_162311 (https://flic.kr/p/24pc97M) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

[britlude]

The other side of the bolts is the motor link connections

https://farm8.staticflickr.com/7886/47264805731_934be2b563_c.jpg (https://flic.kr/p/2f1Cu4D)IMG_20190302_162420 (https://flic.kr/p/2f1Cu4D) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

Fortunately nice and clean in its sealed box!



I then took off the passenger side end cover, very slight play in the end bush, so that will be investigated later! Anyhoo, here’s what’s under the cover….

https://farm8.staticflickr.com/7887/47264805251_9cf2908026_c.jpg (https://flic.kr/p/2f1CtVn)IMG_20190302_164042 (https://flic.kr/p/2f1CtVn) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

grease looks a bit tired!!!

and this is what often causes the eps knock


https://youtu.be/u2o8-ZE5KWc

(and the common dry gear sound as the steering swings!!!....and apologies for the wobbly camera!!!)

this seems to be a roller track needle bearing, that's not playing anymore....the centre can turn easily in the ball nut pin, and the outer is pushed in and 'staked' with 3 centre punch dots to stop it coming out.... that's the next step if i find replacements

[britlude]

Better vid....


https://youtu.be/YQZHdo0CR6Q

[ozon02]

It's nice that you took the trouble and showed the steering rack from the inside
it's good that you can replace the corroded spanner screw
it's good that there is no play on the special bearing bolts
you will not need to send the complete part to the Japanese for refubished
thanks to Jonathan

....I think it is a plain bearing
https://www.fluro.de/images/main/produktbilder/gelenk1.jpg

[goldnsx]

Nice. The EPS costs some serious money. Interesting to see how you refurbish it.

[ozon02]

....from the new video I see that, unfortunately, there is also play (paralell- at the same time) between the bearing (inner race)and the pin

[Pride]

Yet another fantastic investigation and explanation of the dreaded EPS knocking/play fault Jonathan. 👏👏

Good luck in finding the correct bearing type of which I'm sure you will. 👍

I feel so pleased to have non EPS now. 🤗

[britlude]

Yup, definitely a bearing arrangement that has failed.... If I cannot find the correct bearing it will get a spherical joint of the same dimensions, or a custom bush... I have seen pics of someone with a Tig welder in that area!!!!

[britlude]

further down, the sensor gears look ok.....

https://farm8.staticflickr.com/7877/32324659307_071bea819e_c.jpg (https://flic.kr/p/Rfqk3c)Sensor area... (https://flic.kr/p/Rfqk3c) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


the gears dont seem to have any missing teeth....

https://farm8.staticflickr.com/7827/46543122134_9f67519226_c.jpg (https://flic.kr/p/2dUREF1)IMG_20190303_112845 (https://flic.kr/p/2dUREF1) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

D1guy on NSXprime has pics of these with teeth broken off, so I shall check the HPC catalogue and see what they have, i'm sure it'll be a standard metric MOD pitch


...just now got to get the steering input housing bolts to shift.... bent one tool, just broken the tip off the 'lifetime guarantee' tool i just got in specially, literally lasted 20 seconds! ! that'll be going back then! Honda used security torx bolts, so it needs the 6 spline key, but is 'security', so has a pin in the middle...... this means the tool has a hole in the middle, so is significantly weaker than the usual tool .... having been assembled for 26+ years it's reluctant to move....grrrrr

[bbvnsx]

At the last MOT the replacement rack was showing an early indication of a problem, no loose play, but a slight lag in assist, so my spare rack was taken off the shelf and investigations begin!


I always follow your threads Jonathan! And it is amazing that you decided to work on the EPS! and specially to share with us!


I know you will find the correct parts to put it to work, if others did, you will do it for sure! the big difference here is that you are sharing information and this will help all of us in the future.


when you mention your current EPS rack is showing a slight lag in assist, do you think it could be related to missing teeth on the gears? Asking these because i can also feel that lag and was considering opening my EPS rack to see if that would be the cause... Or do you think it could be something diferent?


Thanks
Bruno

[britlude]

when you mention your current EPS rack is showing a slight lag in assist, do you think it could be related to missing teeth on the gears? Asking these because i can also feel that lag and was considering opening my EPS rack to see if that would be the cause... Or do you think it could be something diferent?




i'm not sure what the cause of that is, as the rack i'm stripping didn't do that, it just had the knock if i went over a bump, and the dry bearing/gear sound.....

[britlude]

Well, the 4 input shaft housing bolts did not want to play (sad face) after breaking the security torx bit, bending the security torx key, we tried a little lateral thinking…. Are the bolts hardened? Rubbing a file over them shows they are not, so a quick careful drill and the centre pip is removed, turning the security torx screws into normal torx screws….. so I have another set of tools I can use…. Alas they are still too tight, and instead of the tool breaking, the head ‘smudged’.. yup, def corroded in!

Oh well, drill them out then, removing just the head, to give….

https://farm8.staticflickr.com/7903/46357482515_894b251a27_c.jpg (https://flic.kr/p/2dCsdtV)The sensor bolts would not come undone .. (https://flic.kr/p/2dCsdtV) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

Drilling just enough to take the head off, leaving me a stub to work with….. obviously the unit should just pull off now it has no fixings holding it…. ‘should’

You know that wasn’t the case, having to fashion a ‘jacking’ jig to separate the 2 pieces of aluminium….. that was a faff, but eventually it moved!!!


Seems there was corrosion on the bolts, and corrosion on the aluminium faces were keeping it in place. Still once off I could work on the bolts remains, 3 are out, one is still being stubborn so is soaking before I attack it further!!!

https://farm8.staticflickr.com/7824/40307475333_5f237792cc_c.jpg (https://flic.kr/p/24pQm8g)The sensor bolts would not come undone .. (https://flic.kr/p/24pQm8g) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


Shaft was removed, motor magnet assembly next, then the motor and base, 3 black allen headed bolts buried in a black hole!

https://farm8.staticflickr.com/7850/40307475243_2d4eebda94_c.jpg (https://flic.kr/p/24pQm6H)The sensor bolts would not come undone .. (https://flic.kr/p/24pQm6H) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

Soon it was looking like this….
https://farm8.staticflickr.com/7843/46357483815_294c4eb079_c.jpg (https://flic.kr/p/2dCsdSk)The sensor bolts would not come undone .. (https://flic.kr/p/2dCsdSk) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

(seems all the other ‘exploded eps rack’ pictures on the internet have vanished)

[britlude]

Motor commutator cleaned up with some 2000 grit paper!

https://farm8.staticflickr.com/7835/32330105337_9a587215e7_c.jpg (https://flic.kr/p/RfUeXg)The sensor bolts would not come undone .. (https://flic.kr/p/RfUeXg) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


And the dry bearing/gear noise???? Seems that is caused by the motor brushes, so not a lot I can do about that unless there are some suggestions from the floor! (shall see if that’s improved by the commutator clean)


hmm. seems the nsxrackrepair people in america are unwilling to send me a kit of the overhaul parts,but want the rack sent to them..... :(

[ozon02]

Maybe if you change the rotor bearings you will get rid of unwanted bearing/gear noise

...and by the way it looks like in the past the commutator was on the lathe deep correction

[britlude]

The noise is definitely the brushes... Take the springs off, release the brushes and spin the motor, the noise stops... I shall seat the brushes when I reassemble... New bearings going in of course

That would be a serious cut in the commutator to get a step like that ... Pictures of other motors (now few and far between) show the same layout.... If the copper segments were that ''blocky' they'd be too heavy to stay bonded on with the motor spinning....

[ozon02]

I found some photos from Japan from the refubished EPS process and I suggested them - now I know it's a factory design commutator


13631

13632

[britlude]

where did you find those pics?????

right..... back to the casings, and getting the last seized bolt out..... i tried 'footprint' pliers.. no go, tried my decent mole grips, alas running out of metal to grip, i dug out a m6 nut and placed it over the remaining stub......

then hit it with my mig welder....
https://farm8.staticflickr.com/7881/32339099627_8eaabff885_c.jpg (https://flic.kr/p/RgGkDe)The last seized bolt.... (https://flic.kr/p/RgGkDe) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


a combination of having something decent to put a spanner on, and a huge amount of heat (it was glowing orange!)....

https://farm8.staticflickr.com/7916/32339099547_60c35da3c6_c.jpg (https://flic.kr/p/RgGkBR)The last seized bolt.... (https://flic.kr/p/RgGkBR) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

out it popped :)



next up was the spigot needle bearing that locates the far end of the input drive spindle.... deep in a blind hole....

https://farm8.staticflickr.com/7868/33405308188_46531ebbc8_c.jpg (https://flic.kr/p/STUWis)The last seized bolt.... (https://flic.kr/p/STUWis) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

now the usual trick is to fill the hole with grease, and then use a snug fitting drift, hammering it into the hole, the grease gets pressurised and hydraulics the bearing out... unfortunately this is usually used on sintered/solid bushes, and the needle rollers give enough space for the grease to escape..... so onto something thicker....



and ta-da......

https://farm8.staticflickr.com/7808/32339461017_4814f77d76_c.jpg (https://flic.kr/p/RgJc56)Bearing removed with a candle!! (https://flic.kr/p/RgJc56) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

candle wax did the trick! i've also seen it done with bread! basically you are jamming something malleable into the hole, and the only thing that can move is the bearing!

[britlude]

i managed to lever and tease the ball screw yoke bearings out.... to find this.....

https://farm8.staticflickr.com/7809/32340035517_28c9815622_c.jpg (https://flic.kr/p/RgM8Rg)2019-03-04_07-58-38 (https://flic.kr/p/RgM8Rg) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

turns out they are a sort of soft mount, and the soft bit has decided not to do it's thing anymore. i shall try to source some, if not i shall turn up some plastic inserts. i'm guessing they act as a shock absorber between the rack and the ball screw, but not a lot of shock spacing, as there's negligible clearance between the inner and outer metal when assembled..... at least there's a picture of it on the internet now!


this is the back side of the ball screw.....

https://farm8.staticflickr.com/7820/46558785654_69c2306fc6_c.jpg (https://flic.kr/p/2dWeWTG)IMG_20190304_200311 (https://flic.kr/p/2dWeWTG) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

inside there is a track that matches the track/thread you can see on the screw. ball bearings sit between the 2, and so the ball bearings have somewhere to roll to, they come out of the nut, and then go back in through the tube on the back..... you DON'T really want to split one of these, it can be done, but getting the balls back in the system is a right pain!

[britlude]

i asked the guys in america if they could supply a 'overhaul' kit of bearings, the bronze bush that goes in the passenger end, and their replacement gear for the sensor unit.....


Mr. Delmonte.... he say NO.


so i have to source my own bearings, obviously had they supplied the bearings, i would have kept their numbers confidential, as they have done their research.... however, this is now MY research.... so.....

https://farm8.staticflickr.com/7916/32340077177_996d8baef6_c.jpg (https://flic.kr/p/RgMmex)IMG_20190304_200031 (https://flic.kr/p/RgMmex) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

input shaft location, and the ball screw end support....

https://farm8.staticflickr.com/7912/32340077077_8acc1cc8fd_c.jpg (https://flic.kr/p/RgMmcP)IMG_20190304_200111 (https://flic.kr/p/RgMmcP) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

and the motor bearings..... (both the same)

https://farm8.staticflickr.com/7922/40317348333_f4b997953d_c.jpg (https://flic.kr/p/24qGX2p)IMG_20190304_200227 (https://flic.kr/p/24qGX2p) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


it's not rocket science, it's nothing secret, they are standard bearings..... and the part numbers are written on them!



it didn't help that they gave me a load of schpeel as to what caused the 'dry' noise.....


Screeching and clicking is a result of the bushings causing the main shaft to sag, which causes the brushes on the armature to drag across the com. This causes excess wear on that motor, so just keep that in mind the longer you wait, the more effects it could have on your rack.


as the motor is supported both ends by the pictured bearings, it's never going to move relative to the brushes unless there's catastrophic failure of the bearings, in fact the bearing is mounted to the brush pack!..... the only bushing in the rack is at the passenger side end....hmmm......


yes, they annoyed me!!! lol

EDIT... one of the motor bearings has the bore opened up by 1mm to clear the gear end of the motor....

[ozon02]

.....do not give up just go to the turner (machinen shop) and make these bronz bushings before assembling

[britlude]

I have a lathe in my garage ;)

Oh, and all the bearings mentioned so far have replacements on their way!!!!

[Kaz-kzukNA1]

Hi, Jonathan.
Don't want disturbing your nice thread with photos from different source so I'll just place the link to it.
https://minkara.carview.co.jp/userid/711133/blog/c991096/

This is from KSP Engineering that I used to deal/help with in the past.
I don't like them using the know-how from people who used to work/help them in the past but there are so many photos in the above link that may help others one day through your thread so going to just leave it here.
All of the main members from KSP are now moved to T3TEC and Mr Toyoizumi is the first person who developed the EPS rack service in Japan.
Even the Honda dealers in Japan are using their EPS rack services these days.

There are like 15 pages in the link and at the very bottom of each page, you will see strange Japanese text like ' 次のページ >> ’. It means ' Next Page >> '.

If you need extra photos or info, happy to help.


Kaz

[britlude]

very handy, thanks Kaz....

what it has shown is that the 2 motor bearings are not the same after all, yes, they are the same part originally, but the inner race at the gear end has been opened up from 35mm to 36 mm to give an extra clearance for the gear teeth.... i'll have to make up a little jig so i can re-size the bearing accordingly.

[britlude]

stage 1...... get a chunk of metal and whittle to give a snug bearing location, and a raised section to support the centre race.....

https://farm8.staticflickr.com/7851/40327393283_a86c8f024d_c.jpg (https://flic.kr/p/24rAr3c)IMG_20190305_191120 (https://flic.kr/p/24rAr3c) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


so the bearing fits thus...

https://farm8.staticflickr.com/7904/40327394423_b19b1f9669_c.jpg (https://flic.kr/p/24rArnR)IMG_20190305_191135 (https://flic.kr/p/24rArnR) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

stage 2...... get another chunk and do much the same, but with a thru hole.....

https://farm8.staticflickr.com/7856/33416416438_a2dc5892d6_c.jpg (https://flic.kr/p/SUTSp1)IMG_20190305_191107 (https://flic.kr/p/SUTSp1) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

bolt it all together....

https://farm8.staticflickr.com/7895/33416416428_6dea49c745_c.jpg (https://flic.kr/p/SUTSoQ)IMG_20190305_191205 (https://flic.kr/p/SUTSoQ) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

and then wait for the new bearings to arrive.......

[britlude]

https://youtu.be/hR1LE14vktU


yup, that runs true.. less that 1/2 thou total deflection :) seems the old bearing is not perfectly round... we'll see what the new one runs like before machining!

[Nick Graves]

Your engineering prowess is to be admired.

I hope re-assembly goes smoothly. And the rack...

[britlude]

Hopefully the cutting tips are tough enough, if not i'll be making a small grinding mount to fit to the lathe..... It's only 0.5mm I've got to cut ....

On an aside, the sensor gear appears to be a 0.5mod 60tooth gear, 3mm wide and a 3mm hole.... I've got 2 in brass on their way, 5mm thick for a fiver each.....

[britlude]

the next little job..... replacing the ball screw bush core....now, it once might have been rubber but after many years was like a hard plastic, perhaps with a little flexibility, but now definitely hard and brittle.....

if it was once rubber, perhaps to protect the ball screw drive gear, there was never very much 'give' as the centre top hat base size has virtually no clearance to the outer, so any give would have fractions of a millimetre to move....

anyway, i made some nylon replacements and fitted them, pressing them together in the vice

inner, outer, replacement and old insert

https://farm8.staticflickr.com/7803/40347634003_09616b560f_c.jpg (https://flic.kr/p/24toaU8)2019-03-07_10-21-11 (https://flic.kr/p/24toaU8) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


one assembled, the other waiting!!!

https://farm8.staticflickr.com/7816/32370707297_676431ebf0_c.jpg (https://flic.kr/p/Rjukv4)IMG_20190307_170332 (https://flic.kr/p/Rjukv4) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

[RedCarsGoFaster]

This thread is gold. :)

[britlude]

ta muchly.....

the bearings turned up today, the one that has a bore of 35mm, and needs a bore of 36mm at the gear end of the motor....

well, loaded it up in the lathe, and took a preliminary cut, in full expectation that i was going to have to fashion a dremmel mount and make a basic grinding jig..... anyway, this happened.....

https://farm8.staticflickr.com/7920/47266376922_5dbb71e18f_c.jpg (https://flic.kr/p/2f1Lx89)It fits (https://flic.kr/p/2f1Lx89) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

it cut!!!! so, an hour later, with very gentle cuts so the tip didn't shred itself, and to keep heat out of the bearing, and an awful lot of measuring.....we ended up here.....

https://farm8.staticflickr.com/7825/47318734291_478c6e7c01_c.jpg (https://flic.kr/p/2f6oT9p)It fits (https://flic.kr/p/2f6oT9p) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

the new bearings are nice and tight, showing just how loose the old ones have got over 26 years!!!! the bearing at the brush end of the motor is more worn/loose than the gear end one..... so the unmodified bearing has worn first in my case

that's all the bearings sorted then! (the completely standard needle rollers arrived a couple of days ago!)

[britlude]

Now it's nearly at reassembly stage, any suggestions on what grease to smother it in????

[Pride]

Now it's nearly at reassembly stage, any suggestions on what grease to smother it in????

I can't answer even the simplest of your questions let alone the problems you've solved to get it to this stage, power to the Steampunk. 😂😂😂

[Kaz-kzukNA1]

The type of grease changes the EPS feeling dramatically.
At the factory, it was using the clear, really-really soft (like gel) grease.

Many professional bike maintenance people are using Royal Purple Ultra Performance Grease and I used it for a long time for other applications and loved it.
There are two NLGI grade. Considering the EPS rack structure, I would say no.2 would suit for the rack.

T3TEC uses it but from time to time, they use their own know-how to blend something in so may be different from the original product.

It's purple colour and just wants to stay there forever so don't let it on the cloth, carpet, etc.
Even on the floor, wiping it off is not enough.

Not sure how easy it is to get hold of it in UK though as local chemical regulations and transportation requirement changed quite a lot over the last several years.

No longer possible to hand carry the boot lid/eng hatch glass damper on flight even with SDS.
Honda had to include MSDS, SDS, etc documents inside the parts bag for the brake caliper service kit, drive shaft grease, etc.


Kaz

[britlude]

I have seen the gel type mentioned, seems to be an '''oil grease', an oil but in a gel form.....I can't really go by my rack as the grease in mine was black and had a crust!!!!! VW apparently do a rack grease... Its not like we can ask honda!!!
Fortunately I don't have a dead line.....

[goldnsx]

Honda has a steering rack grease. Part no. 08C35B0534L. Not sure if it's the one you need. At least it says P.S and the color is some kind of transparent white.

[britlude]

hmmm grease available in usa, unavailable here on a quick Lings search...... anyhoo....

started reassembly, bearing fitted in brush housing, commutator fitted, lock nut tightened and staked!

https://farm8.staticflickr.com/7876/33453471638_2fa0f7f327_c.jpg (https://flic.kr/p/SYaMBL)IMG_20190309_140830 (https://flic.kr/p/SYaMBL) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

a quick spin still showed one of the brushes wasn't happy and still rattled, so a piece of fine sandpaper on the commutator and with the brush springs on, the brushes were trued to the comm again....

https://farm8.staticflickr.com/7844/33453471668_c3ddaa4e24_c.jpg (https://flic.kr/p/SYaMCh)IMG_20190309_140516 (https://flic.kr/p/SYaMCh) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr



https://www.youtube.com/watch?v=LZViWTbYEbU

the sound IS on!!!! motor is now silent, smiley face!!!:)

new bearing in to support the end of the ball screw....

https://farm8.staticflickr.com/7836/40363813253_af76c7f406_c.jpg (https://flic.kr/p/24uP6qH)IMG_20190309_164056 (https://flic.kr/p/24uP6qH) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


and the ballscrew yoke bushes refitted and centre popped to 'stake' it in....

https://farm8.staticflickr.com/7898/46605959074_14f28fea91_c.jpg (https://flic.kr/p/2e1pHUw)2019-03-09_05-08-29 (https://flic.kr/p/2e1pHUw) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

royal purple grade 2 available here..https://www.rivalmotorsport.co.uk/royal-purple-ultra-performance-grease

i was waiting on a reply re. grease and passenger side bush from a local steering rack specialist, alas on hearing it's electric, they seem to have had some sort of breakdown and doesn't want to help..... the bits i'm asking about are common on all racks!!!! and ignored the grease query!

(have the forum rules changed??? this post has 4 pics, a vid and a smiley, AND still posted....... i thought there was a 4 pic/item limit????) anyway, as you were!!

[UnhuZ]

Hi,

man... you amaze me... now i can send you mine when the time comes...
you are officially the EPS dude in Europe !!!

Thanks,
Nuno

[Silver Surfer]

Hi,

man... you amaze me... now i can send you mine when the time comes...
you are officially the EPS dude in Europe !!!

Thanks,
Nuno

Jonathan doesn't tend to do work for club members routinely....you just have to follow the steps he has outlined. ;)

SS

[britlude]

i'm just putting my findings out there! if it works when i'm finished, that's a bonus! lol

i just like to add to the pool of knowledge. i could have just sent it to the US, or Japan, for rebuild, but where's the fun in that????


back on track, royal purple grease has been ordered...... and the motor powered up to check it works and bed in the bearings a bit.

they are shiny new and tight, so i powered it up and gave it a half hour run in, not that its ever going to be running in one direction for anything like that time, it means the bearing grease can be worked a bit... gave it a run in the reverse direction too, the loads reducing sufficiently for the current required, at a fixed voltage, to drop by a third!

[UnhuZ]

Hi,

i was joking.... obviously that i cannot impose on someone to work :P :P
(but i can beg LOOOOL)

but although i could do this work myself, but sourcing all the parts because i
don't have tools to do parts myself, i prefer to have someone do this for me...
i'm affraid i could do something wrong and compromise the whole rack.

But yes Jonathan, it's here for future reference, and i follow every thread of
yours very religiously ;)

Thanks,
Nuno

[havoc]

I can't answer even the simplest of your questions let alone the problems you've solved to get it to this stage, power to the Steampunk. 😂😂😂 Seconded. Absolutely bowled over by your persistence there Mr Sutherland!

[britlude]

next up, the 2 gears i ordered have arrived..... i bought 2 just in case of disasters, but only need one.... there have been several reports of the plastic gears losing a tooth or two from the guys in the US...

so made a quick split jig to hold it on the lathe.....

https://farm8.staticflickr.com/7890/32439081187_bcf9052437_c.jpg (https://flic.kr/p/RqwLFe)IMG_20190314_172925 (https://flic.kr/p/RqwLFe) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


and soon it was looking a bit more like the plastic original....

https://farm8.staticflickr.com/7917/33504465278_5fef17d545_c.jpg (https://flic.kr/p/T3F9fs)IMG_20190314_174100 (https://flic.kr/p/T3F9fs) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


now..... i ordered a 0.5mod 60tooth brass cog, knowing there would be a slight discrepancy with diameters... the one on the input spline is exactly the same size..... so i know the designers know what a standard mod pitch is!

https://farm8.staticflickr.com/7822/33504466928_bf77b76d9e_c.jpg (https://flic.kr/p/T3F9JU)IMG_20190314_175002 (https://flic.kr/p/T3F9JU) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr


and the original plastic measures....

https://farm8.staticflickr.com/7804/46657545824_7dbdc0cb30_c.jpg (https://flic.kr/p/2e5Y7Rf)IMG_20190314_175015 (https://flic.kr/p/2e5Y7Rf) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

so 0.6ish mm smaller.... it's still 60 tooth, and the tooth form isn't obviously damaged, but it might have had wear over the last 26 years, but not so sure.... this isn't an issue at the splined shaft side, as there was loads of backlash,



https://www.youtube.com/watch?v=puvRQFh5gOY


so that gets reduced nicely...


https://www.youtube.com/watch?v=3af4e0v3jjw

however the sensor side is too tight to fit the gear...

so the plastic gear is loose on one side, and meshing nicely on the other, so it was made small then? so slightly off pitch - ok for a less backlash mesh, but then loads the other side??? ok, thanks, make it easy why don't you!!!


soooo... a slight tweak required to get it in, the sensor gear has to move over a little.... a quick desolder and file....

https://farm8.staticflickr.com/7860/33504465248_01c0d9c66f_c.jpg (https://flic.kr/p/T3F9eW)IMG_20190314_182413 (https://flic.kr/p/T3F9eW) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

literally less than half a mm to correct....the position was tweaked toward the original position to get the mesh better.... now it has a little adjustment!


so once put back in, all is well...

https://farm8.staticflickr.com/7865/40415235753_87fd48b2a5_c.jpg (https://flic.kr/p/24zmDxx)IMG_20190314_183035 (https://flic.kr/p/24zmDxx) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

oh, and drilled some holes in the gear, just cos i could!





now on the subject of 'why didn't you use standard parts when you design this stuff', the steering rack end bush on a eps rack.... the steering rack main shaft is 24mm diameter, so a 24mm inside diameter bush, approx 25mm long, and the outside diameter of that bush appears to be 26mm (haven't taken it out yet)

your standard steel backed industry size bush, meaning you can have oilite, ptfe, teflon or even more exotic options, is 24mm inside diameter (tick), 25mm long (tick) and 27mm diameter, 27mm! 1mm bigger!!!!

[ozon02]

I think you should not duplicate the American guys idea and improve Japanese engineers. If your plastic wheel had all teeth. Why ... ask Kaz, he'll explain to you.
Stiffening the structure in a place where the unevenness of the road is directly transferred to the material is not a good idea.

[bbvnsx]

If you go to the USA rack repair website and click on their services, they divide 91-96 and 97+ NSX. By looking on their description I was under the impression Honda changed the torque sensor on 97+ cars... and that Honda eliminated the plastic wheel on 97+ cars... but did Honda change to metalic wheel or a complete different torque sensor? :-/


I think you should not duplicate the American guys idea and improve Japanese engineers. If your plastic wheel had all teeth. Why ... ask Kaz, he'll explain to you.
Stiffening the structure in a place where the unevenness of the road is directly transferred to the material is not a good idea.

[goldnsx]

Just a sidenote and not of any relevance at all: but regarding the costs of a new unit and the complicated repair I'm pretty glad to have a manual steering gearbox (which is reliable except for one bushing). The EPS is simply not needed in an NSX. Question: I've never run across it but would it be possilbe to throw the EPS out and install a much cheaper manual gearbox instead?

Great effort on the repair though.

[britlude]

1. the gear, nylon or otherwise, is on the steering wheel side of things, so isn't in quite such a harsh environment, having a damper, in the shape of the driver, attached. however there are various documented cases of the gear teeth breaking, both with d1guy in US and KSP in japan.... add to that, my rack being 26-27 years old, so don't want to trust the old nylon gear.... and as i had it all apart anyway.... and honda not supplying any internal rack parts....

https://farm5.staticflickr.com/4883/32442563337_0417e91cf4_z.jpg
courtesy of KSP..... https://minkara.carview.co.jp/userid/711133/blog/c991096/p3/

2. yes the EPS steering rack changed with the NA2 update, the NSX getting a new steering torque sensor and control ecu..

3. the eps, as far as i know, is the same steering ratio, so all you have to do is remove the motor components and it's exactly the same as a manual rack anyway.... however, i'm sure you can just delete it and fit a manual rack if you have the urge.... tho the EPS does make slow speed maneuverability easier, and the assist is speed dependant, so once you get moving it doesn't assist anyway!

[ozon02]

ok Jonathan, you convinced me - I am ordering from you an enlarged bearing (to 36mm) and gear (bronze?or brassing?) for future:)

I love my EPS
1. I was invited to the *** Fest in Poland last year. Connected to Track Day. I met a friend from NSX 92. We decided to exchange cars (mine is Acura 96)
2. my feelings about non-EPS:
92 used on the track definitely better - more responce from road
92 on the high way road - ok, I did 130 km
92 in Town - unacceptable
3. a colleague's feelings about the EPS
96 used on the track - unacceptably poor feeling (it was a 1.5 km track - not the Nurburgring Nordschleife, a bit similar to the Nurburg GP) - it's worth adding that last year's friend won the second place in the Polish cars' GP to 2 liters of capacity on Honda S2000
96 on the road Approx
96 in Town much better than 92
...... and because I'm not "fast and furious" I think it's better to have an EPS and the costs of repair are acceptable

[Nick Graves]

Interesting.

Does your Polish colleague have the EPS on his S2000? Without chassis braces, that IS numb!

There is a difference across NSXs, but personally I don't find it a stumbling block. I thought the 17" front wheeled car was the numbest, but I wonder if wheel size or alignment was as much of a factor as anything else? It would perhaps equally explain why a 92 feels sweetest on its cotton-reels.

[goldnsx]

92 in Town - unacceptable
Please keep in mind that one major variable is missing here and that's the ET (not the alien of Spielberg) of the wheels, I mean their offset.

A stock NSX with stock wheels/tires (all years) is very, very acceptable in town, even during parking. The forces dramatically increase when people run lower offsets (40 mm or less) and wider rims on the front. So, it's not the car's fault or even the one of the engineers. The lower offset values also contribute to the detoriation of the bushings within the steering gearbox and so on.

I took this into consideration while ordering my wheels and choose an offset of close to stock, 50 mm on a 7.5'' wide rim in the front. It doesn't look 'sexy' but the car drives close to stock and much better than with the previous aftermarket wheels which were ET 43 on 8'' wide rims.

Hondas are a little bit tricky and special about the offset of the wheels chosen by the factory, esp. the models with FWD. It has always been hard to find aftermarket wheels with an ET close to stock. See Integra, Civic Type R, S2000...

Enough of OT, sorry for that.

[ozon02]

let's not clutter up this beautiful thread. Is there a sense to open a new one?
As you know, I respect your opinion and knowledge of the model. I shared my impressions.
92 auto had factory wheels 15 front 16 rear ,tires I do not remember.
This thread shows that I am not a fan of correcting the factory (plastic gear for brass gear,....... supercharger etc.)
After the first Track Day I bought a Big Brake front but it involved buying the offset disk. But I noticed the deterioration of traction. I bought a Big Brake wheel friendly but in size 17 front 18 back. Another change for the worse. I bought Tein Suspensions RA-good for track bad for Town I bought OS Giken 4.40 LSD. More fun. The next step would be turbo but enough - it's a bad direction. I bought a different car.

[britlude]

getting back on track.......

this looks somewhat better.....

https://www.youtube.com/watch?v=pnopMqMVEfg

no clunking now..... :)

one thing i did note.... there wasn't any dowels/location for fitting the ball screw mount to the motor when assembling the rack... there's holes through the various components (motor bearing mount, ball screw mount and end cover) so some pins were made up to align during assembly, and make sure there was no looseness/backlash between the motor and ball screw gears.....

one side was a small hole....
https://farm8.staticflickr.com/7856/33530384308_5b7d927bb1_c.jpg (https://flic.kr/p/T5XZ5h)IMG_20190316_140618 (https://flic.kr/p/T5XZ5h) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

the other side was a larger hole through the top 2 items, but a flatted hole cast in for the motor bearing plate....
https://farm8.staticflickr.com/7902/33530384288_81580fd4cf_c.jpg (https://flic.kr/p/T5XZ4W)IMG_20190316_140628 (https://flic.kr/p/T5XZ4W) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

just to be awkward, so a pin was tweaked at the end.... ok, probably overkill, but, anyway, no backlash and everything moving fine!

re. the passenger side bush.....
https://farm8.staticflickr.com/7884/33530384268_9814838b22_c.jpg (https://flic.kr/p/T5XZ4A)IMG_20190316_141125 (https://flic.kr/p/T5XZ4A) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

.....i decided to leave it as is for the time being, the play was minimal before i stripped it, and a good grease will lose that.... so i put the circlip back in.... btw.. if you get a 'knock bush' it'll just go in to the slightly larger stepped end (ironically circa 27mm, you know, standard industrial bearing size!!!)

so the rack is buttoned up and complete with new rack end knuckles, gaiters and steering ball joints! it's smooth with no knocking, brushes rattling or play anywhere. it's slightly stiffer, but that's down to the motor bearings now being new and tight, rather than 150k miles old rattly ones! i'll just have to be careful on the first few drives, making sure the self centreing is ok (a D1guy scare story on one of his messages! along with various references to 'bushings' when meaning 'bearings'!)

i can push the steering rack by hand, so steering geometry doing it should be fine!



....now i can get back to other stuff!!!!

[britlude]

as it was a pleasant day i got a chance swap in the steering rack....

! started at about 10:15....
https://farm8.staticflickr.com/7860/47448114012_265e3a4ff5_c.jpg (https://flic.kr/p/2fhPZef)IMG_20190330_101753 (https://flic.kr/p/2fhPZef) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

once i had the car on the front axle stands, i fashioned a simple tracking gauge to mark the current alignment (a laser pointer taped to a stick that sat against the front wheel edges, and put a dot on a bit of tape stuck on the rear wheel, when marked, this gave me a reference to get everything basically in the right place with the new/old rack!)....i also marked the input shaft and seal to show me where the exact centre point is!

.....and an hour later....

https://farm8.staticflickr.com/7838/46777281744_58201c9224_c.jpg (https://flic.kr/p/2egxNaE)IMG_20190330_111942 (https://flic.kr/p/2egxNaE) by jon sutherland (https://www.flickr.com/photos/152809076@N06/), on Flickr

and another hour and a half it was all back together....

pleased to say it's all working as it should, no play, slack spots, tight spots, or anything else untoward! took it out for a test drive, wary of the 'won't self-centre' scare comments, and all was well, no knocks or unusual noises!

so, if you have any of the mechanical symptoms, they are, touch wood, cureable, as they are essentially a basic mechanical system that's just bearings and gears!!

[britlude]

update, now its been in a week....

when i put it together, i set the preload clamp bolt ( the one that presses the rack onto the input shaft) as per the honda service manual instructions, tighten to 4nM, release, do it again, back off 20 degrees and tighten the lock nut.

the weight on the input shaft was then checked as per manual at 3Kg at 100mm lever length (ie. gently clamp on some grips on to the input shaft, measure out 100mm from shaft and pull at that point with a spring balance...) so i double checked it was about that, it was, and fitted it all in....

if this is how it's supposed to be, then no wonder auto cars get a bad press with 'dull' steering.... it's like driving in treacle.... yes it all does what it's supposed to but its heavy going.... i expected it to be tighter, as there's more drag on the shiny new motor bearings, but the motor assist will offset that...so a bit more investigation....

the eps rack, according to the service manual is set to a load of 3kg on the 100mm lever....
the manual rack is set, according to the book, at 1.5kg... so it's half the turning force when there's nothing connected to start with!

i then checked the rack i removed, which was comparable to the original rack when i swapped it in..... 0.7kg!!! no wonder Sarah thought it was really light when she drove it!

fortunately the rack clamp bolt is easily accessible under the car, so a quick jack up, back off the lock nut, do the double torque up, and back it off about 40 degrees, check there's no play or issues, there's not, so all back together... i did a spring balance check on the steering wheel before and after, and i suspect i'm closer to 2kg/100mm now, not as loose as the manual rack, so splitting the difference!

the result, much nicer :)

so, lost the knock going over bumps, the other rack had a small dead point when you rocked the steering (probably a combination of the torque sense mechanism getting sticky and play in the ball screw mount as well and hence this whole investigation) so obviously lost that, and lost a 'knock' from the input shaft every 360 degrees (probably that loose plastic gear related)

so that's the steering rack sorted!

...and i've got the one i took out to go through too..... at my leisure!!

[Heineken]

All thumbs up for the work, I'm truly, truly impressed!

PS: My rack got serviced at KSP when the car was still in Japan (google translator version of their procedure here (https://translate.google.com/translate?sl=ja&tl=en&u=http%3A%2F%2Ftyiz.jp%2FNSX%2FPowerSteering%2FGea rboxOH.html)).

[pralognan]

I'm also impressed and want to thank you for sharing this with us. Can I ask for comment on my power steering?
Its a 1991 UK car,all original. When I bought it I thought the steering was heavy when cornering at moderate speeds,but felt fine whilst parking. I read an old 1991 Motor Sport road test,"The steering felt light and deft whilst parking but any kind of cornering effort felt so heavy that we thought the power steering had failed. Over a thousand miles it became less disconcerting....."
Car magazine in 1997 said that "at speeds of more than 87mph assistance is virtually nil"
Has anyone else had similar experience and is there any adjustment possible?

[Pride]

I'm also impressed and want to thank you for sharing this with us. Can I ask for comment on my power steering?
Its a 1991 UK car,all original. When I bought it I thought the steering was heavy when cornering at moderate speeds,but felt fine whilst parking. I read an old 1991 Motor Sport road test,"The steering felt light and deft whilst parking but any kind of cornering effort felt so heavy that we thought the power steering had failed. Over a thousand miles it became less disconcerting....."
Car magazine in 1997 said that "at speeds of more than 87mph assistance is virtually nil"
Has anyone else had similar experience and is there any adjustment possible?

If your car is a totally original 91 manual transmission NA1 then you DON'T have power steering.
Electric power steering was only fitted to auto transmission models but from 1995 all NSX's except R's were fitted with it.
Hope this helps.

[RedCarsGoFaster]

If your car is a totally original 91 manual transmission NA1 then you DON'T have power steering.
Electric power steering was only fitted to auto transmission models but from 1995 all NSX's except R's were fitted with it.
Hope this helps.

IIRC the 1991 Motor Sport review was of an auto; the 1997 car reviewed by Car magazine would have had EPS. If you do have a 1991 manual, these comments are not applicable to your car.

However, if you do have a 1991 auto and therefore have EPS, that experience sounds normal.

The steering is set up to have more assistance the slower you go. As such parking is easy, but yes, steering loads will increase significantly at higher speeds.

I've seen several different speeds quoted for the point at which assistance is effectively switched off and I'm not sure which of them to trust. My car (1995 manual - see above) certainly feels like assistance switches off a long way below 87!

As regards tuneability of assistance, no idea. Per the OP's adventures there is some tweakability, but adjusting the speed at which the assist comes in and out sounds like a different challenge.

[pralognan]

Thanks for your responses. Yes my car is automatic,so I tend to follow Britlude's adventures.

[Kaz-kzukNA1]

Don't want going off topic with Jonathan's thread but I felt good place for the EPS reference so here is what I felt.


For your reference, with JDM, EPS was available as an option on MT model since 93.


Honda did modify the hardware and software on many occasions especially on the controller side but broadly speaking, there are two spec on the EPS rack and (sort of) three spec for the controller side.
Depending on the combination, you will get different feeling.


Definition:
Rack A: With rotational sensor + torque sensor, up to 96.

Rack B: Only with the torque sensor, WITHOUT the rotational sensor, 97+.


Controller I: The original two separated boxes (power and controller), 91 - 94.
(Strictly speaking, 91-92 controller was only designed to communicate with the AT controller whereas 93+ one could be used not only for AT but also on the MT model through pulser unit so some differences but for the ease of explanation, going to treat them as the same two box style).

Controller II: One box solution, power and controller all in one box, requires both the rotational and torque sensor input, 95 - 96. (Can't be used with Rack B explained later.)

Controller III: Same one box solution as spec II, only requires the torque sensor input, can be used with both the Rack A & B, 97+.


My personal feedback (could be different from yours depending on the chassis setup, etc):

Rack A + Controller I:
Your feedback is probably spot on.
The power assist suddenly disappears (more like On/Off feeling) at around 30 - 40mph.
You can feel this sudden loss of assist.

Also, when you turn the wheel while moving the car to position it on the lift, you can feel tiny delay in the assist response.
Hard to explain the feeling but basically, you turn the wheel just a tiny bit but you don't get the assist immediately and like 0.2sec later, you feel some sort of 'knock' through the steering wheel as the effect of initiating the power assist.

For the clarification, this 'knock' is different from the one you will get when there is a small play at the metal bush inside the EPS rack (as you can see in Jonathan's video) or the click/knock that can happen if your universal rack joint is loose.


Rack A + Controller II:
The power assist is much more changed smoothly/progressively and almost no assist around 50 - 60mph.
There is still the response delay as described above.


Rack B + Controller III:
The best combination.
Again, smooth reduction of power assist as above and felt like even better over A + II but back to back test was done against A + I so it could be my imagination.
Still, the power assist changes are very smooth.

And the biggest difference is the response time.
From time to time, I have two NSX with EPS, one with 97+ and the other the pre-97 AT or MT EPS model.
There is no delay in assist response with 97+ that you could feel on the 91 - 96 EPS models (A + I, A + II).



I haven't tried the combination such as A + III so can't comment on this.

Honda did modify the hardware mainly for the reliability issue for the Controller II & III many times so my feedback may not cover all of the spec.

Also, the chassis setup especially the tyre and F/R rake would change the feedback dramatically so may not be the same for your spec but at least, hope you can get some idea on the differences over the EPS generation.


Kaz

[bbvnsx]

I haven't tried the combination such as A + III so can't comment on this.


Thanks for the detailed information on the EPS setup. My NSX is a 1993 EDM 5MT with EPS and the delay on the assist become more noticeable when i changed to the Type S steering wheel (expected as the steering wheel is much lighter and will let feel the transition better), to the point i thought something was wrong with the EPS.

When driving the car this delay is not a problem, only when parking the car or maneuvering at very slow speed I can definitely feel it

If association of rack A + controller III could improve the response time I would try this for sure... someone must be the guinea pig... maybe me... if i can source a 97+ used controller at a fair price... would this be P&P? (since we go from 2 separated boxes to 1 box)

[NZNick]

If your car is a totally original 91 manual transmission NA1 then you DON'T have power steering.
Electric power steering was only fitted to auto transmission models but from 1995 all NSX's except R's were fitted with it.
Hope this helps.

Not quite true Clive - your statement applies to UK cars, but not to JDM, as EPAS became an option from the introduction of the NA2 with C32B engine. All Type T (targa roof panel) cars (& all NA1 automatics) have the EPAS, but coupes (excluding the Type R & S Zero) could specify it and most did.

[philboo]

Not had much time to read the forum or even get out in my car this year but reading this I love the skill and enthusiasm of the members here to fix and share their knowledge. Thank you for the time taken to share this. Thumbs up

[ozon02]

Hi Kaz
if I would like to try the A + III configuration, what P / N for controler do I need to buy .Will Plug & Play work?

Mario

[bbvnsx]

After surfing some japanese blogs (with the help of Google translater) I came to the conclusion that probably to get the faster response on the rack you need the newer rack (B), as it is the torque sensor on the rack that was improved. So if you intend to upgrade the EPS controller to get the faster response you probably won’t get the desired result.
Kaz can probably help you further on this...

you can get more information here (just translate it and you get an idea):

http://www.tyiz.jp/NSX/PowerSteering/PowerSteering.htm




Hi Kaz
if I would like to try the A + III configuration, what P / N for controler do I need to buy .Will Plug & Play work?

Mario

[ozon02]

To BBVNSX,
thank you very much valuable hint - it will save me time and money

:rolleyes:

[britlude]

a quick appendix with a couple of thoughts.....

1. if the motor bearings are dry but not showing signs of corrosion, the side shields can be carefully pried off and the bearings cleaned, re-greased and the shields put back on..... you don't have to go too mad with the grease, too much and the steering will feel like treacle. bearing in mind the motor only spins 20 times lock to lock, it's not like its doing 6000rpm for days on end.

2. the ball screw yoke bushes.... i'm guessing they are a micro shock damper with a bit of give in them. so in theory you could use some of the 2 part liquid rubber to restore them, the sort that boy racers use to stiffen engine void bushes and the like, or make replacements for obsolete engine mounts.... they are available in different hardness levels, but not idea what they should be for the secret bush in the steering rack!!

probably shore a70 or 80, but just guessing, something like this, a liquid rubber https://www.mbfg.co.uk/pt-flex-85-rubber.html or polyurethane https://www.mbfg.co.uk/duroflex-85.html but more investigation would be required!

[britlude]

appendum 2, 4 years later..... now i had thought the steering was heavy, a bit dull, for a while, especially after i had to buy a new daily driver as my commute had changed significantly.... but after driving Mikes (sorepaws) (ta!) around the block, it was confirmed, it was, and something had to be done!

so i dragged out my spare rack and set to giving at an overhaul just in case the one in the car had terminal issues....

fortunately, with the new commuter car, i don't have to try to get everything done before the next working day, so a more relaxed approach, (fortunate with supply issues/timings)

spare rack…
https://live.staticflickr.com/65535/52892187576_e479c4e4d0_c.jpg (https://flic.kr/p/2ozUhCy)IMG_20230416_094530 (https://flic.kr/p/2ozUhCy) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

Strip to find the usual cause of the knock….

https://youtu.be/Xdvx2SULIWA

so strip it to bits….
Working the bushings out…
https://live.staticflickr.com/65535/52892645583_836a482270_c.jpg (https://flic.kr/p/2ozWCMe)IMG_20230413_200730 (https://flic.kr/p/2ozWCMe) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

https://live.staticflickr.com/65535/52892645638_2c32d640bc_c.jpg (https://flic.kr/p/2ozWCNb)IMG_20230413_200725 (https://flic.kr/p/2ozWCNb) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

Don’t look as bad as the other ones…
https://live.staticflickr.com/65535/52892580225_fcdded678a_c.jpg (https://flic.kr/p/2ozWimn)IMG_20230413_201518 (https://flic.kr/p/2ozWimn) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

Oh….
https://live.staticflickr.com/65535/52892580140_8dcdcbb650_c.jpg (https://flic.kr/p/2ozWijU)IMG_20230413_201751 (https://flic.kr/p/2ozWijU) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

Replacement inserts made out of nylon…
https://live.staticflickr.com/65535/52892580130_684ddba974_c.jpg (https://flic.kr/p/2ozWijJ)IMG_20230413_204657 (https://flic.kr/p/2ozWijJ) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr
And all pressed together…
https://live.staticflickr.com/65535/52892580080_2ddcd44b71_c.jpg (https://flic.kr/p/2ozWiiS)IMG_20230413_210029 (https://flic.kr/p/2ozWiiS) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr
Reassembled and staked into place
https://live.staticflickr.com/65535/52892357579_08b5b9ca7a_c.jpg (https://flic.kr/p/2ozVaaD)IMG_20230413_212940 (https://flic.kr/p/2ozVaaD) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

[britlude]

Do the sensor gear mod….

Remove gear
https://live.staticflickr.com/65535/52892188756_12419551ab_c.jpg (https://flic.kr/p/2ozUhYU)IMG_20230414_133907 (https://flic.kr/p/2ozUhYU) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

Modify the brass spare I bought 4 years ago….
https://live.staticflickr.com/65535/52892188996_6b28c9ac93_c.jpg (https://flic.kr/p/2ozUi43)IMG_20230414_131153 (https://flic.kr/p/2ozUi43) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

Tweak the sensor ‘motor’ mount to allow the gear to mesh properly…
https://live.staticflickr.com/65535/52892357454_05e4034250_c.jpg (https://flic.kr/p/2ozVa8u)IMG_20230414_133903 (https://flic.kr/p/2ozVa8u) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

Reassembly is reverse of disassembly
https://live.staticflickr.com/65535/52892188836_6a994d72dd_c.jpg (https://flic.kr/p/2ozUi1h)IMG_20230414_134755 (https://flic.kr/p/2ozUi1h) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr


I did strip it right down to bare components, but the motor bearings weren’t dry like the other rack 4 years ago, and spin freely. I had already decided that the ‘stickyness’ of the rack in the car was down to the motor bearings being new and fully loaded with grease.

Anyway as a reference I added vice grips (not tight enough to do any damage) and gave it a flick…

https://youtu.be/-l6pbVe8Ej4 (https://youtu.be/-l6pbVe8Ej4)

this is with everything assembled and suitably tightened..

side note… on a typical steering rack, the ‘stiffness’ of the turning action is adjusted with the cup that presses the rack onto the input pinion…. On the NSX it makes little or no difference relaxing it from the workshop manual setting… what has helped is fully synthetic grease, more like a gel than a thick grease….

[britlude]

After getting the rack out of the car, I did a comparison flick test….


https://youtu.be/0j0N6-Y2qqw

yup, definitely stickier! I did the appropriate workshop manual spring weight pull tests, and they were all within spec, but this illustrates that the book settings don’t tell the whole story

on strip down, the ball screw nut bushes were perfect, but the motor had obviously been stressed….

A bit of build up….
https://live.staticflickr.com/65535/52892355914_7791faa577_c.jpg (https://flic.kr/p/2ozV9EW)IMG_20230422_162418 (https://flic.kr/p/2ozV9EW) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr


Not pretty
https://live.staticflickr.com/65535/52892360196_b9bd9b8d55_c.jpg (https://flic.kr/p/2ozVaWL)2023-05-12_07-25-28 (https://flic.kr/p/2ozVaWL) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr


So cleaned up, the brushes inspected, and the commutator cleaned… all ok

This time I took the bearings off, carefully prised the rubber side seals out, cleaned the bearings, lightly regreased with the fully synthetic tube of magic, and reassembled

Resulting in….

https://youtu.be/l70-dStfziY


again, all tightened up as it should be, so a vast improvement 😊

it was ready to put back in, except for one slight issue….
https://live.staticflickr.com/65535/52892187386_644db2cd42_c.jpg (https://flic.kr/p/2ozUhzh)IMG_20230422_125300 (https://flic.kr/p/2ozUhzh) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr

I know they are not OEM, but you’d expect them to last longer than 4 years….
Oh well, lesson learnt….
https://live.staticflickr.com/65535/52892544254_e945b166c2_c.jpg (https://flic.kr/p/2ozW7Eb)2023-05-12_07-32-39 (https://flic.kr/p/2ozW7Eb) by JON SUTH (https://www.flickr.com/photos/197052607@N08/), on Flickr


Back in, it feels a whole lot better, so another addition to the knowledge pool 😊

[Heineken]

Nice work! May your rack be rattle free for a long time :)

[bbvnsx]

Amazing work!!! Thanks very much for sharing! Really nice information for us with EPS!

[ozon02]

Interesting thread.
By the way - I'm curious how we will deal with failures of the control unit in the future.
I think it's time to bring up the topic of preventive replacement of capacitors.