Clutch help pls...

[NSXGB]

Had a new clutch (dual plate) fitted yesterday complete with JUN lightweight flywheel.

Technician test drove the car & signed the job off. I drove the car 5 or 6 miles gently before joining the motorway on the journey home. As I joined the motorway I gave it a bit of throttle to overtake a car & I sensed the clutch slip slightly. I say 'sensed' as I was unsure whether it was the new lightweight flywheels' eagerness to rev...
I resumed driving it gently thinking the clutch may need a bit of bedding in...
Joined the M25 in 'full on' rush hour and found myself in start/stop traffic where the clutch started slipping again and got quite bad so I pulled up on the hard shoulder. I let it cool for 20 mins & the clutch was back to normal but decided to get it recovered home as rush hour was still in full swing and I didn't want do do any (more?) damage....
Clutch pedal 'seemed' to get harder to push but the biting point was still high \ where expected.

Was I asking too much of a new clutch?
Is there a usual bedding in process \ period for an NSX clutch?

Going to take it for a gentle spin later to see what happens...The garage who fitted it confirmed that was the next step to take...

Anyone got any ideas?

[duncan]

When you speak to the garage next, get the 'technician' to explain to you how he set the clutch up to initialise the plates. If he can't do this or his procedure is at variance to that in Honda's works manual [see attached] you have your answer.

[NSXGB]

Thanks for the reply Duncan.
I'm hoping that the garage I took it to, being probably the number 1 NSX specialist Honda dealership in the UK would know by now how to initialise an NSX clutch by now, hopefully I'm right?!
I took it for a drive today, driving gently, gave it a little bit more throttle after 15-20 miles and she still slips...clutch pedal feels slightly heavier than it should.
From what I can gather, if the clutch initialisation is not carried out, you won't get the car in gear, initialise it incorrectly and the biting point will be very low...bite point is about where I would expect it at the moment.....

[Kaz-kzukNA1]

Hi NSXGB.

Bit more information on your clutch and Gbox will help in assisting you but I think it is best to take it back to the Honda garage that you mentioned before you try anything.


It could be simple as slave cyl push rod not seating properly to the release folk or, to the level, where you need to take the Gbox off again…


You may have clutch pressure plate not sitting properly at release bearing, problem with the release bearing guide, etc or may be the clutch is not slipping but something else….


You mentioned that your pedal was getting heavier when you had the issue so it sounded like around the pressure plate.


In your post, you mentioned ‘dual plate’ and ‘NSX clutch’.
Is it OEM or aftermarket one?
Any modifications to the Gbox?
If you made any modifications, may be it is causing the problem?


Regarding the initialisation, I have never tried running NSX without carrying it out but helped other owers for it.

All of them had difficulty or grinding noise when trying to select the gear so it sounds like different story to yours. If your clutch is new and OEM, you can do the initialisation without removing the gbox any way.

Hope it will be solved very soon.


Regards,
Kaz

[NSXGB]

Thanks for your reply Kaz,

The clutch is a complete new OEM unit, flywheel is a JUN lightweight.
I originally had a 5 speed gearbox in the car but was changed for a 6 speed unit which has the NSX-R input shaft (to allow use of twin plate clutch) and 4.24 final drive. This is the reason for fitting the new clutch.

I bought the grearbox in good faith from another member here, AFAIK it was working fine when it was removed.

Is there a scenario within the gearbox that could give me these symptoms? Differential?

I hear no obscure noises from the box at all. Only symptoms are the slightly stiffer clutch pedal & slippage...

[NSXGB]

As a side note, a month ago I replaced the clutch master, slave cylinder and rubber hose, all was working fine with the old 5 speed box.

When I picked up the car they told me that they removed the slave cylinder for the work, therefore had to bleed the system and charge me more for the fluid used. I was under the impression that the slave cylinder did not need to be disconnected to remove the gearbox?

[NSXGB]

Got a theory.
Speculative as I won't get a chance to look at it till tomorrow & I'm not accusing the garage of any wrongdoings... But...
The slave cyl didn't need to be disconnected, that's just making more work which garages aren't inclined to do. Let's say that the car is in bits on the ramp & either the clutch pedal was pressed accidentally or the cyl was upended and the pushrod pops out of slave cyl..fluid leaks, rod has to be pushed back in...rubber seal damaged / misaligned / pinched, whatever. Now, seal not happy & occasionally tucks awkwardly when pedal is released and therefore not releasing the clutch fork fully - clutch slips & pedal feels heavier due to the misalignment of the seal.
What do you think?
If that is true, I'm not too chuffed at them charging me for the clutch fluid!

[Kaz-kzukNA1]

Hi, NSXGB.

As in my first post, if you have a question mark, it would be best to take it back to them and have a look while the problem is still there.

Or, if you are worried about driving to there, I'm quite sure there is a way to flat bed your NSX to there.

I have a good idea on where you took your NSX and the service manager is a very knowledgeable and good customer support based on several cases including the recent one with another owner.


By the way, I remembered you had problem with your CL hydraulic system just a day before heading to the Nurburgring.

I think it was about last summer??


Just a matter of interest, did you adjust anything (pushrod length, pedal height, etc) at that time or when you replaced all of the Master/Slave/hose recently?

Normally, you don’t need to adjust anything if you use OEM parts and if all adjustment were left as they were from the factory.

However, unless you are the first owner of your NSX, who knows what was done in the past.


For CL service, you don’t need to break the hydraulic line.

CL Slave Cyl will be just hanging around inside the engine bay.

From time to time, the two bolts attaching the Slave Cyl to the GBox could get corroded and thus, easier to disconnect the CL hose and push in the plunger to release the release folk but this is not the case as you replaced the Slave Cyl just a month ago.

May be they found something not quite right with the pedal feeling and bled the system??

I have never tried it but even you accidentaly pressed the CL pedal while the Slave was still in the air, I'm not sure whether you can shoot the piston on the floor or not....

The plunger is just sitting on the small piston and there are only two simple rubber seals there.

There is a rubber sleeve (the accordion, not the cover) at the plunger so even you accidentaly popped the piston out, may be it will be held inside the sleeve?


I presume you bought the 6MT GBox (trans case + clutch case) with the main shaft and final driven gear already replaced so you didn’t change anything.

Therefore, if it was working fine before the removal from the other NSX, it would be very unlikely to be GBox issue.

Unlike other cars, all of the gears including the Reverse one are helical type on our NSX so if you have a problem with gear alignment, it will pop out of the gear and loose the drive unless it was jammed.

If GBox was never opened, then the only thing exposed to the outside world from the clutch point of view is the release folk, release bearing, bearing guide, hanger and hanger/spring related parts.


Hope your issue will be solved very soon so that you can enjoy the good engine response with nice shift feeling and improved acceleration of your modified 6MT.

Do you have EPS or not??


Regards,
Kaz

[NSXGB]

Thanks for the reply Kaz.
I do not have EPS, just regular biceps :)

About 4 weeks ago I replaced the clutch master, slave and rubber hose while still attached to the 5 sp trans. I used the car plenty of times after that and with the old clutch everything worked fine (all way to VTEC and back) Bolts were all ok.

The piston can come out very easily from the slave cylinder. Like you say, this is behind the bellows.

I was going to ask you whether there was a rebuild kit available for it as I kept the old slave cyl just in case.

[NSXGB]

...back to the garage tomorrow....:(

[Kaz-kzukNA1]

Hi, NSXGB.
Wise decision.

Hope they will sort it out for you.




...........
I do not have EPS, just regular biceps :)
...........
I was going to ask you whether there was a rebuild kit available for it as I kept the old slave cyl just in case.

Without EPS....
Then, you don't need to worry about triggering the EPS warning on the later spec EPS brain when final ratio was changed.


By the time when you have to replace the Slave Cyl, the metal body would be very rusty so I normally just replace the whole assy.


Having said this, it would be a good idea to have emergency rebuilt spare in case the new one is on back order.


I don’t think there is an ‘all-in-one’ service kit like the brake calliper or brake master cyl so I’ll just list the individual parts.

8641

1: 43352-567-000 Bleeder
2: 43353-SD5-003 Cap
16: 46932-SL0-003 Piston
17: 46933-SL0-003 Cup A
18: 46934-SD4-901 Cup B
19: 46935-SL0-013 Spring
20: 46937-SD4-003 Boot
21: 46938-SL0-003 Push rod
51: 95701-08025-08 ( x 2 ) Bolt, 8x25

********************************
15: 46930-SL0-003 ( Slave Cyl, Assy )


Kaz

[WhyOne?]

...back to the garage tomorrow....:(

Sorry to read about your troubles Simon.

Hope this is sorted as swiftly & painlessly as possible.

:)

[NSXGB]

Having said this, it would be a good idea to have emergency rebuilt spare in case the new one is on back order.

You read my mind, although my next one should be a few years away hopefully.
As long as the bore in my old one is ok..

Thanks Ian, hope it's a simple fix otherwise I'll be coming home in a Jazz....

[WhyOne?]

Thanks Ian, hope it's a simple fix otherwise I'll be coming home in a Jazz....

I'll race you in my Aygo!

[NSXGB]

....the car in front will be a Toyota....
:)

[WhyOne?]

..yes.....but only because the throttle has stuck open!

[NSXGB]

All sorted, thanks for the replies & thanks to Norton Way for sorting it out today.

I hoped it would be something simple...
Even though the clutch pedal feel and the clutch was ok before the gearbox swap & new clutch, it seems that all that was required was a slight adjustment of the clutch pedal.
When the fluid warmed up & expanded there was not enough play at the top of the pedal & the expanding fluid only had one way to go - pushing the slave cylinder & thus slightly pressing the clutch fork.

My only explanation as to why it worked ok before the clutch was changed was that maybe there was a little air in the system still. They bled it for whatever reason & the symptoms appeared....

All good learning experience. :)


Anyway, what a difference the gearbox change has made, grin factor 10.



Thanks all.

[m666 edd]

Nice one.

I'd only want a 6 speed with a 4.55 final drive :)

[Chazzi]

Is this something that would occur if the slave was not bled after fitting the new clutch?

I only ask as it sounds like this would be possible if the slave was still taking up the wear from the old clutch and the hydraulics had not been touched? (I am not familiar yet with the NSX clutch!!)

[NSXGB]

Nice one.

I'd only want a 6 speed with a 4.55 final drive :)

I'd think that would be pretty quick off the mark. There's a noticeable difference going to 4.23.
Don't you have the 4.55 in your 5spd? Do you have JDM gearing? If yes, there's not much point for you going 6spd...

[NSXGB]

Is this something that would occur if the slave was not bled after fitting the new clutch?

I only ask as it sounds like this would be possible if the slave was still taking up the wear from the old clutch and the hydraulics had not been touched? (I am not familiar yet with the NSX clutch!!)

I don't think the hydraulics need to be bled after fitting a new clutch. Any slack is taken up by the slave push rod which finds it's own level with the release fork. AFAIK.

[m666 edd]

I'd think that would be pretty quick off the mark. There's a noticeable difference going to 4.23.
Don't you have the 4.55 in your 5spd? Do you have JDM gearing? If yes, there's not much point for you going 6spd...

4.4 & JDM ratios.
4.55 & 6 speed would be the only worthy upgrade but certainly not worth the money!

[NSXGB]

I had tall UKDM gears in mine originally, JDM gears are a lot more user friendly. A lot of wedge for the upgrade still but you can't take it with you..

[WhyOne?]

Excellent!

Pleased your problem was both simple and swiftly sorted Simon.

[NSXGB]

Yes, thanks Ian, we must be due a Sussex mini meet soon?...:)

[markc]

Good news that it was a simple and cheap solution :)


I'd only want a 6 speed with a 4.55 final drive :)

IMHO you'd only want the 4.55 ratio for a track car as it would further damage the cars cruising ability on the road. I guess it depends on your priorities and where you do most of you NSX miles.


I'd think that would be pretty quick off the mark. There's a noticeable difference going to 4.23.
Don't you have the 4.55 in your 5spd? Do you have JDM gearing? If yes, there's not much point for you going 6spd...

There is approximately 4% difference (actually just under) between each of these final drive ratios. In theory this provides 4% more torque (ignoring loses) reaching the the road for any given engine revs (in any gear) although of course you have to change up sooner. On the flip side it will result in a 4% increase in revs for any given road speed (in any gear).

I knocked up a little spreadsheet to provide an example of cruising ability (in top gear) at 4000rpm... (results rounded up or down to nearest whole mph)
Standard or JDM 5spd = 93mph
5spd with 4.235 = 89mph
5spd with 4.44 = 85mph
5spd with 4.55 = 83mph
Standard 6spd = 101mph
6spd with 4.235 = 97mph
6spd with 4.44 = 92mph
6spd with 4.55 = 90mph

For me the 6spd with 4.235 final drive is the pick of the bunch... just ignore 6th when you're in the mood for a proper charge :)

Cheers

Mark

[ollie]

Yes, thanks Ian, we must be due a Sussex mini meet soon?...:)


Hi Simon , glad you got your clutch sorted , i would be up fo a sussex meet

steve

[NSXGB]

Ok, I'll look at some dates and post something in the events section.
The Victory pub in Staplefield, where we met last time, has apparently shut down so it'll be The Cricketers or another recommendation....

[lotusolly]

A mini meet would be good.

Wanted to make the other 2 recent events but had other things going on.
Think the car is starting to feel a bit neglected!

Olly

[m666 edd]

I'm pretty sure mine is a 4.4 final drive rather than 4.44. I think that is a more recent size. But anyway a 6speed with 4.55 (a comptech size I believe) would be lower rpm in 6th gear than I currently have in 5th.

As it stands I don't find the revs too high for motorway driving, it's not like I'm trying to get diesel economy anyway! Also it has the benefit of having the peak bhp at the right time for over 160mph.

Excuse the semi hijack :)