Houston, we have a problem.....

[britlude]

looks like my gearbox is giving up the ghost...gotta in thru the diagnostics to work out just what but does Anyone know of an auto box out there? And if i were to be offered a flappy paddle box, would that need the later AT ecu and other mods? Very sad face

[NSXGB]

Bad luck Jon.
Man of your calibre could build yourself one.
Obvious recommendation would be to contact Dirk.
I'm only guessing but I'd put money on the fact that the F-Matic has a different control unit, or an extra one for the paddle control. Maybe a comparison of the parts diagrams could give you that info.

[AR]

Sorry to hear that, what oils were you running in the box?

[britlude]

Dirk says he has an early flappy paddle from a Very low mileage 1996.....

[AR]

If you can integrate it you might be able to get a proper set of paddles and different wheel. You will need a gear indicator too I think?

[jpspringall]

If you can integrate it you might be able to get a proper set of paddles and different wheel. You will need a gear indicator too I think?

Yep, the Gear Selector Clustor is slightly different as there a digit LED to show you the gear when in 'manual'

Would be interested to know if you do end up changing the steer wheel/paddle.

Though if you look for my previous post, the paddle is part of the combination switch rather than the paddle.

James

[britlude]

what i was aiming as was to find out if the flappy paddle box and the normal auto box are the same beast just with different ECU...

ie. are the boxes the same or is there extra hardware on the later auto.

it's looking more towards my box being rebuilt... :(

and looks like an expensive addition to my build thread.....

[sorepaws]

Ouch ! Ouch !

[Kaz-kzukNA1]

Hi, Jonathan.

Sorry to hear the news.
What kind of problem are you having?
Slipping CL discs or can’t even get into the gear?
Any flashing of ‘ D ‘ indicator?

Honda AT is quite different from other manufactures and it’s using multiple discs at each gear modules. These discs are submerged in ATF and the AT controller will let the discs to slip by controlling the oil pressure to achieve smooth shift up and down.

Because of this mechanism, eventually the discs will wear out.

In Japan, apart from Type-S and Type-R that were only available as MT model, AT was more popular than the MT among the Coupe and Targa models.

The very common failure mode on AT models in Japan is that the multiple clutch discs at the 3rd gear module worn out too far resulting in excessive slip and if kept driving, the dust from the discs will block the ATF strainer and eventually no longer be able to build up the oil pressure resulting in no gear selection at all.
Obviously, before getting to this stage, there is a certain sign of failure such as excessive slip at the time of gear change.

At this stage, I don’t know what kind of issue you have.
It could be internal AT box issue, input sensor, solenoid issue, etc.


Although the controller itself is different between the original and F-matic, the basic control (shift and lockup solenoids) is the same.
F-matic manual shift lever +/- sw is NO(Normally Open) type so without the lever module, it will simply do the full automatic shifting.
By the way, the lever module is very expensive...... Thought about using it for cruise control sw after replacing the steering wheel but gave up because of the cost.....

The manual gear number display on the dash is just the output from the AT controller with the voltage level of three wires so even without them, it won’t affect the AT control.

From hardware point of view, the final gear ratio was changed to 4.4 when F-matic was introduced until some point when it went back to the original spec so you will feel better acceleration compared to the original AT box.

I don’t know whether the oil pressure control software or the servo bodies are the same or not.

I’m afraid I don’t have enough experience to confirm whether it is a plug-and-play swap between the original and F-matic AT box.



If you are going to take the Gbox out by yourself and if you have the access to the spare box, you may want to challenge overhauling the existing one first.
The multiple discs and plates are not that expensive and that's what some of the NSX specialists in Japan are offering as one option for the owners with AT issue if there is no reasonably priced spare box available.

I have very limited experience with AT box but I think you need to be careful by following the specific procedure when stopping the engine before the removal of the Gbox and also specific procedure before/during the first fireup of the engine after the overhaul of AT box.


Any way, first thing first, you need to find out what kind of issue you have with possible failure code available or not.

Kaz

[britlude]

right.... thanks for all the offers and advice.

my box appears to have a hydraulic issue rather than an electrical/ECU issue. with the service connector shorted after a drive that experienced the issues, (and keeping the ignition on to prevent any AT ECU codes going missing, there are no fault codes displayed...

the symptoms are.... select drive, will pull away at light throttle until approx 2200 rpm then will start to slip and lose drive (either 1st gear losing 'grip' or second not engaging)... pull gearstick to '2' still the same, select '3' and no drive until the engine rpm drops to approx 1000rpm, then the gear will engage and drive fine. changing back to 'd' will cause drive to be lost, reverting back to '3' slips until the 1000rpm magic point is hit again, BUT with the road speed slower than when D was tried!

basically i have half of 1, all of 3, R works, and the rest are N!

hence it's not happy! the oil (dextron II as per usual) was brown, but not burnt (about 30k miles old) and the magnet trapped particles on the drain plug were super fine dust, no grittiness or chunks of shrapnel! nothing unusual in the sump...

i drained and changed the oil (which ironically i was going to do before silverstone) just to make sure, and it's still sick.

so the latest state of play is thus... i have a replacement second hand box in my garage now, picked it up this afternoon!

the plan being to fit this (time being an issue) and cross my fingers! there was no core surcharge, so i get to keep my box, then when the need arises i can have my original box rebuilt at my leisure and swap that back in.....

guess what i'm doing at the weekend!!!!

[sorepaws]

umm now what do I think you are doing - ok replacing your gear box? Good luck Jonathan we have faith in you. I am sure Sarah will help out.

[NSXGB]

Good luck for the weekend, better get that gazebo out again!

[NSX 2000]

what i was aiming as was to find out if the flappy paddle box and the normal auto box are the same beast just with different ECU...

ie. are the boxes the same or is there extra hardware on the later auto.

it's looking more towards my box being rebuilt... :(

and looks like an expensive addition to my build thread.....

You must of posted this just after I saw you on MCE driving past the Vauxhall garage, I was waving like a mad man, but I wasn't going to undignify myself by running after you.

Hope all goes well, Paul.

[britlude]

i was probably too busy nursing the car home......

[paulc]

I think there is one for sale on prime.

[Silver Surfer]

Strangely I saw a post on the 'for sale' thread on Prime which indicate the auto box was sold 3 days ago.. I did thought it was you Jonathan, who bought it after seeing this thread subsequently.

Good luck with the fix.

BTW .. I sorted out my ICE system for the time being. ;-)

SS

[Nick Graves]

Best of luck with the swap.

[WhyOne?]

Sorry to hear of your woes Jonathan.

I can offer nothing by way of assistance other than bucket-fulls of kudo's (surely worth more than €'s now!) for getting the transplant in place an undertaking it yourself.

Hope everything goes smoothly for you.

:)

[britlude]

well.. it's under way!!! i'll do a write up later, but so far the car is on stands in the garage (weather report looked too dodgy for a gazebo event!) the driveshafts are pulled and most of the odds and sods on the top side are removed. i did the driveshafts in 2008 so all fairly straight forward, sooooo glad i copper-slipped all the fastenings!

i've ordered a transmission jack, on a next day delivery, so once thats here i can drop the box!

the gearbox i found was 25 miles away from me, and the cheapest i've seen this side of the Atlantic. so had to have it! it's supposed to be a low mileage, but i'm sure they ALL are when they are being sold! Anyway the plan is fit it and if all is well be happy! if it's not I have my box i can have rebuilt!


going well so far... fingers crossed

[Senninha]

So with the jack arriving 2mrow I guess with you that means you've booked to take Sarah out in the NSX 2mrow night then .....

All the best, wish I was nearer as could at least offer a pair of hands to assist ...

regards, Paul

[britlude]

latest update/progress report.... started this afternoon (friday) at 2, by 6 the old gearbox was out and the replacement in. just need to reassemble the driveshafts/suspension tomorrow. fingers crossed it'll all be ok ( and after seeing the news, that Silverstone will have dried out by the classic!)

the jack worked like a dream!

[NSXGB]

How high did you have to get on your axle stands to clear the gearbox on the transmission jack?

[britlude]

new box is in and works a treat... until about 3 miles into a journey and then goes mental. now, i've either got a second duff box, or the AT ecu is throwing a mental when it warms up.

i'm going with the second option, which killed my original tired box.

all sensors and solenoids on the box were checked before they went in, but the erratic moves the box is making point to the ecu, even tho it's not throwing any codes

i have a s/h AT ecu on it's way from USA, but if previous delivery is anything to go by, it could be stuck in customs for 5 days! a real pain as the classic is not far away.....

arse,

not smiley face

[NSXGB]

Bummer.
Have you looked inside the old control box to see if there are any burnt / leaky components?

[britlude]

Yup, tried that.. All looks shiny new

[Kaz-kzukNA1]

Hi, Jonathan.

Unless you saw the flashing ‘ D ‘ indicator on the dash, you won’t get the error code from AT controller.

You won’t be able to put the AT controller or any of the controllers such as ECU, TCS, ABS, etc into diagnosis mode unless you have switched off the IG completely and short the SCS terminal before turning the IG SW back ON again.

In other words, you must short the SCS terminal before turning the IG SW On.
Each controller must see the Low level at the SCS terminal before powering up.


It is very unusual for AT controller to fail but it could happen.

Just a matter of interest, what kind of issue are you having with your replacement AT Gbox?
Is it exactly the same issue as your original AT Gbox?

How did you check your ATF level after swapping the AT Gbox?


Kaz

[britlude]

hi Kaz, the only transmission code i've seen is 15, which relates to one of the gearbox internal speed sensors, after refering to the manual, and checking for appropriate ohm measurements and continuity and making sure all the connections were clean and good the error was cleared. (the error did also appear prior to the gearbox change, but again was cleared after investigation) no other codes have shown themselves.

the old gearbox had become slow on initial takeup, that is, put it into drive and wait a couple of seconds for it to engage and be ready for the off. after that all was fine, until last tuesday.

as described earlier, (excuse the quick copy and paste...)


the symptoms are.... select drive, will pull away at light throttle until approx 2200 rpm then will start to slip and lose drive (either 1st gear losing 'grip' or second not engaging)... pull gearstick to '2' still the same, select '3' and no drive until the engine rpm drops to approx 1000rpm, then the gear will engage and drive fine. changing back to 'd' will cause drive to be lost, reverting back to '3' slips until the 1000rpm magic point is hit again, BUT with the road speed slower than when D was tried!

basically i have half of 1, all of 3, R works, and the rest are N!

with the replacement box the initial take-up is instant, put it in D, the gearbox engages to go forward! drive and everything is ok, shifts are as expected (more definite than the old box, but that did have 100k miles on it), can now detect to downshifts when rolling to a stop. all is good, i haven't leant on the throttle, not knowing the history of the box, just easing it back into service gently!

after a couple of miles i lose all drive, no gears at all. not good. if, however, i switch off the engine and ignition, and restart, i can continue on as i was, gearbox fine for another 1/2 mile until it happens again. and repeat. each time the 'next' distance slightly shorter. this gets me thinking it's a control issue with a heat duty cycle coming into play. of course i can only eliminate that with another AT ecu... which is en-route

the other hint towards an ecu problem is the loss of drive happened at pretty much the same distance from my house, the same right turn where i have to stop to cross traffic, with both gearboxes.

fluid levels in both boxes are as per service manual, checked after engine ran, gears cycled through, back to park, shut off engine, and check level within a minute!


while i'm waiting for the ecu i shall continuity check all the signal/control wires to and from the gearbox.




How high did you have to get on your axle stands to clear the gearbox on the transmission jack?

i bought myself some new axle stands, they came out at 410mm high on rear jacking points, front wheels chocked on the floor. this gave me enough height, but mine's auto, the gearbox only has to move away from the engine about an inch before it can drop straight down, everything remains level. all you with the pudding stirrer boxes have a clutch and gearbox input shaft to consider so i suspect need slightly more room to play with.
HTH

[sorepaws]

Jonathan,

how easy is it to remove the AT ECU ? - a thought: I could bring my NSX over Monday 16th and you could try a temporary transplant from mine to your car

[Senninha]

http://www.nsxprime.com/forum/showthread.php?t=163442

Good Luck Jonathan ....

[britlude]

thanks Mike for the very generous offer. However i shall politely decline as, although the ecu is easy to get out, there can be any number of unseen problems that may result in me having 2 NSX shaped garden ornaments out the front of the house.

as i'm not completely sure it IS the AT ecu at fault, though it's looking likely from where i'm sitting, if it is then it may have been knocked out by another issue, and i wouldn't want to risk damaging a unit that's come from another running car.

ie. is the AT comp faulty? if it is, then is the fault the cause or effect?

(it's also it's a thinly veiled ruse to get your car to my house where the door panels would miraculously fall off along with the window regulators :yes:)



thanks Paul, that one is also on its way to me....

......so there is a race upon us, one from USA with the associated customs hurdles, and a second from our distant colony of Australia!

the plan being to have a 'i know it works' spare, for myself and for this situation should someone else be unfortunate !

[Silver Surfer]

Even SOS is trying to help......

http://www.nsxprime.com/forum/showthread.php?t=163611#post1599711

SS

[Nick Graves]

Jonathan,

It's just a clutch at straws, but have you gone through the loom joints & checked for corrosion/high resistance? I know a couple of people with older S2000s that had a similar sort of EPS issue, and that's what it turned out to be. The main engine loom through the bulkhead on those is occasionally prone to water ingress and sometimes the engine ECU appears to have gone mental when it hasn't.

[NSXGB]

All fixed yet Jon?