NSX Clutch Advice

[rednsx3]

Hi,
I am having trouble with the NSX Clutch. I am have changed one every 800 to 1000 miles and my NSX has done 32k miles.
The last one I bought was from Science of Speed, the Sport 275.

I want the clutch pedal effort to be as close as possible to the OEM clutch.

Any advice on the Spec Stage 1 and the Clutch Master clutches?

 

[solidol]

I have about 25k street and 500 track miles on sos275. No issues so far. Expect it to last at least for another 50k.

What issues are you experiencing?

 

[JohnWayne]

So you have been through 30 clutch's on the car?
Just trying to verify information.

You may consider deleting the oem clutch damper to help with feel.

 

[RYU]

It sounds like you have an incorrectly adjusted clutch.

 

[docjohn]

bingo.....

 

[rednsx3]

I got the car in 2001 and at that time it had done around 25,000 miles and it needed a clutch. So, the original clutch lasted that long.
after that, I have replaced 5 or 6 till now and hardly drive the car.

I also feel that it is an issue with the clutch instalation, but the technicians are not able to figure out what they are doing wrong. They are following the instructions as per the manual and the ones that came with the clutch.

The last one, I got installed by the local Porsche dealership, but it didn't make a difference. It lasted around 500 miles.

 

[jwmelvin]

Are you also adjusting the clutch pedal so it has some free play before engaging? That’s a potential issue that would cause slip and clutch wear. I was upset my SOS clutch lasted only 14k miles but holy moly you need a new approach. I feel your pain and hope you can find someone to get the next one set up right.

 

[LMR]

I have the original SOS sport clutch with 113K miles on it and still going strong.

 

[Old Guy]

You purchased the car in 2001 with 25,000 miles. You didn't specify the car's actual model year, so is it an early car with a dual plate clutch or the later single plate clutch with dual mass flywheel? Other than the last SOS 275 clutch, have you been replacing the clutch with the original Honda clutch or have you been replacing them with an aftermarket clutch and if so, which one?

If you have an early car with the dual plate clutch, there is an initialization process that must be carried out; but, that only applies if you are re installing a Honda dual plate clutch. Also, I think if you do the initialization incorrectly it won't release period. @jwmelvin mentioned the clutch pedal adjustment. The clutch pedal must have some free play. On my 2000, the free play in the pedal is specified at 13 mm. This is moderately easy to check (not so easy to adjust). Reach down and press on the clutch pedal with your hand. There should be 13 mm of free movement in the pedal before the push rod attached to the clutch pedal contacts the back of the piston in the master cylinder. If you have no free play the clutch may only be partially engaged leading to slippage. If the clutch master cylinder was ever removed or replaced and the clearance on the push rod was not checked this could result in loss of free play.

Is your engine modified? How are your replacement clutches failing? Are they glazing leading to the clutch grabbing or are you actually wearing the lining right off leading to the clutch slipping.

f you have an unmodified engine and you are burning through clutches like the SOS 275 in less than 1000 miles, I don't think the answer is a different brand of clutch.

I have a 2000 with the single plate dual mass flywheel. It has about 120,000 km on the original clutch which still seems to be fine. At the opposite end of the clutch wear spectrum I think Kaz made the observation that Japanese market NSXs burn through clutches because of the combination of traffic congestion and hilly driving conditions. You didn't specify where in India you are from; but, from my exceedingly limited experience India = traffic congestion. If you are doing a lot of city driving, this might be a case where a standard to automatic conversion would be useful.

 

[rednsx3]

Hi,

I have a 1991 Acura NSX.
The first 2 that I installed were OEM clutches and the after that an Exedy. Which was very bad for city driving, and then 2 more from SOS.
I am sure it is an install issue. But, the golden question is, how do I sort this out?

I am willing to fly in a tech from US, pay for his tickets and a nice small holiday in India, if he can sort out this probmem for me

I don't drive on the track at all and most of it is city driving but I still can't believe that one can burn a clutch in around 500 or 1000 miles. I don't so any burnouts or drive wrecklessly.
Very frustrating for me as we don't get parts very easily in India and the turn around time to get the parts into India could be months and that is if they don't get stopped by customs.

 

[Old Guy]

So, what is the manner in which they fail?
- glazing of the lining (clutch chatters or is grabby)?
- loss of lining (clutch is slipping)
- warping of the disc or pressure plate

The way in which they fail may give you some clues as to what is causing the failure.

Did you do the clutch pedal wiggle test to check for free play?

 

[rednsx3]

Hi,

The clutch starts slipping on accelerating hard and this is when the problem starts and then gradual starts to slip even when not accelerating hard.
This is identical to all the clutches which have had to replace till now.
I checked the free play and it was as per the guidelines mentioned in the trouble shooting guide column in the instruction manual which I received with the clutch.

 

[Old Guy]

If you have free play in the clutch pedal, the only other installation issue that comes to mind is a damaged release fork which is preventing the release bearing from completely backing off or incorrect installation of the release fork or release bearing which is causing the same thing. I don't know whether the latter would even be possible.

Unfortunately, as far as I can determine, the Honda service manual does not even provide an inspection guide for the release fork. The manual does not even seem to show the installation of the fork - I am guessing they are of the opinion that it is 'self evident'. This thread

http://www.nsxprime.com/forum/showt...ng-installation?highlight=clutch+release+fork

discusses problems with the incorrect installation of the release bearing; but, the problem is not similar to yours since it was not possible to get disengagement. Also, this was specific to one clutch and your problem seems to apply to all the clutches you try so I am not sure that it is relevant.

 

[natcc99]

This is an interesting investigation because it is surprising that you are going through clutches so quickly. Even according to the wiki page, your case seems odd.
https://www.nsxprime.com/wiki/Clutch#Why_Do_Many_NSX_Clutches_Wear_Quickly.3F
I have to admire your determination. After that many clutches, one might have given up and sold the car.

Perhaps take a look at your damper? (assuming it is the original one and still installed) See links below for some added info. Perhaps some of the experts in this forum could shed some light on whether or not a damaged/worn damper could decrease a clutch life?
http://www.nsxprime.com/forum/showthread.php/107954-Clutch-Damper-Assembly-Why-and-I-don-t-want-this
http://www.nsxprime.com/forum/showthread.php/165887-How-does-damper-delete-affect-clutch-pedal-feel

Good luck

 

[RYU]

[MENTION=23528]Track Addict[/MENTION] might take that ticket to India!

As the smart folks on here have said.. i'd check free play first. You can even check free play with 2 people while one presses on the clutch and the other is under the car checking on fork operation.

My only other *guess* (I emphasize guess because I have not seen the car) is a bent clutch fork or a faulty slave cylinder that isn't disengaging all the way.

 

[jwmelvin]

My installation issue definitely prevented any successful operation of the clutch, and I suspect any other error would be similar. (Other than lack of free play causing partial disengagement.) A bent fork is an interesting possibility though and I imagine replacing the fork, and its pivot point on the housing, would be wise.

Do you definitely focus on driving with as little slip as possible, rushing transition periods? Do you ever smell the clutch during/after driving?

 

[Kaz-kzukNA1]

@rednsx3.
Could be too late but do you have any measurements of the OEM CL after it was removed from the car?
What was the thickness of the 1st (gbox side) and 2nd (flywheel side) friction discs when they were removed?
You must measure both as the wear rate is different between the two.

When you replaced the OEM CL, exactly which parts were replaced?
Ideally, please list all of the parts no..

Is your NSX RHD or LHD?
If RHD spec, I have further question regarding two parts but I'll wait for your answer first.

When you change the gear, do you have any difficulties in selecting the next gear?

Although replacing CL every 500 - 1,000miles is definitely not normal, do you live in the area where you have to use parking brake on launch once stopped?
For example, there are lots of places in Japan requiring this and it's even one of the pass/fail criteria during the driving test.

You seemed to have already checked and confirmed the free play of the CL pedal and the master cyl pushrod but is it the same as this?

Kaz