Your opinion - shuttering after installation of new clutch amongst other things

[hondasash]

Your opinion - shuttering after installation of new clutch - solved

Dear Gents,

have already used the search function and already found some comments, anyhow would like to have your opinion:

Have had a major service done at my 91 NSX > amongst others the car got new OEM clutch plus more or less new tranny.
Car drives fine, all gears get in smoothly BUT I have shuttering = vibrations when clutch engages during downshifting in low RPMS, when starting from first gear and when having the reversed gear in.
Upshifting / shifting in higher RPMs is more or less free of shuttering.

My mechanic which I trust very well said, has recognized that as well when doing an installation lap after everything was installed but he also cannot explain why
I have this vibrations.
He did the initialization of the clutch etc, everything acc. to the manual.

Do you thing the cluth needs a break in time till everyhing works perfect?
I have the SLIGHT feeling that the second day I drove the car, the shuttering was a little bit less but that might only be a feeling

 

[watchdogd]

I am a relatively new owner so I do not have experience with a new clutch but I have it on my clutch occasionally on starting from first which has about 40k miles.

I've read in previous threads that for new clutches it can take 500 to 1000 miles to break in before the shudder goes away and in some cases even clutches with very low miles have it return.

 

[goldNSX]

Could be anything but it's not unusual to have some shudder while down-shifting in an NSX. Depends on how much is much/too much. I use to do rev-matching to prevent a mild shudder. Without it it shudders slightly while downshifting.

Not sure if your mechanic torqued the mounts in the required sequence. But my guess is that your front engine mount is tired/shot.

 

[hondasash]

Mmh.
Also heard it could also be a non greased throw out bearing, non greased main shaft, non clean flywheel etc. etc.

Have had a real big service incl coupling, trans, cooling hoses , LMAs, timing belt etc.
I hate it when the car Is not behaving perfect..:

Could be anything but it's not unusual to have some shudder while down-shifting in an NSX. Depends on how much is much/too much. I use to do rev-matching to prevent a mild shudder. Without it it shudders slightly while downshifting.

Not sure if your mechanic torqued the mounts in the required sequence. But my guess is that your front engine mount is tired/shot.

 

[goldNSX]

Has your mechanic worked on NSXs before?

 

[hondasash]

Yes

Has your mechanic worked on NSXs before?

 

[goldNSX]

What does the 'more or less new tranny' include?

 

[hondasash]

Bought a 15k mile, top maintained tranny from my fellow procar and put it in during Service.
Had syncro issues 1st and 2nd gear in high Rpm...

Shifting is so much better now.

What does the 'more or less new tranny' include?

 

[Old Guy]

Mmh.
Also heard it could also be a non greased throw out bearing, non greased main shaft, non clean flywheel etc. etc.

Have had a real big service incl coupling, trans, cooling hoses , LMAs, timing belt etc.
I hate it when the car Is not behaving perfect..:

If the release mechanism (throw out bearing, fork) was not lubricated, you can get a 'gritty' feel through the clutch pedal as you press and release it. This can make it slightly more difficult to get smooth engagement in the clutch. The common culprit, which is usually accompanied by a slight squeak is the contact point between the plunger and the end of the release fork. The test for this is with the engine off, press the clutch pedal and check the feel and listen for noise. If it feels fine and no noise is present then its not likely that the release mechanism is the problem. If the car is up on a hoist its not that hard to grease the contact point with a little dab of Honda Urea grease. Non lubrication of the actual release bearing is a bigger headache!

I am guessing that your old clutch was worn and might have been slipping a little? The slipping part can make for a smoother engagement. Your new clutch may have a much sharper / quicker engagement which may mean that you have to relearn your clutch technique in order to have a smooth engagement. I have the later dual mass flywheel arrangement and getting smooth lurch and shudder free take offs in stop and go traffic without reving the engine high does require some concentration, even after 8 years of ownership. As an observation, I have never found Honda clutches to be particularly nice. All of them seemed to have very narrow and relatively high engagement points - and that includes 3 different Honda 4 cyl motorcycles which had wet multi plate clutches. It must just be the way Honda likes to design them.

Did you install a complete new Honda clutch kit including flywheels? Flywheel surface problems can lead to engagement problems; however, that is not so likely with a complete new clutch package. In my very limited experience, contamination on the clutch discs can lead to slippage which does not seem to be your problem.

 

[goldNSX]

Did you get the vibrations from day one after the big service? If yes then something is fishy. How did you break in the clutch?

 

[hondasash]

Yes, from day 1.
Drove 350 miles since then, more or less easy drive. Will go ahead driving for some days, if it is not becoming much better he offered me a redo of the coupling on guaranty.
Complete new clutch kit incl. OEM fly wheel was installed, no unusual sound when Pressing clutch Pedal (i know what you mean)

The old clutch was pretty ok, but as everything was changed i did it as well

Did you get the vibrations from day one after the big service? If yes then something is fishy. How did you break in the clutch?

 

[goldNSX]

Yes, from day 1.
Drove 350 miles since then, more or less easy drive. Will go ahead driving for some days, if it is not becoming much better he offered me a redo of the coupling on guaranty.
Complete new clutch kit incl. OEM fly wheel was installed,

A new Honda clutch feels like butter on the first miles, no shudder at all because the friction material has to break in first. While breaking in a clutch you can do more bad things than good ones. If you don't baby it for the first xxx miles it's pretty easy to overheat a clutch when new. Depending on how it has been broken in more or less shudder can result. But as you say it's from day 1 it's hard to believe that your mechanic ruined it by ... whatever. After some time (1000 miles?) every NSX I drove so far had some slight shudder while taking off if the critical frequency/revs were reached. It's not uncommon but with the stress on 'slight' or as [MENTION=26435]Old Guy[/MENTION] mentions: it needs some concentration in stop and go traffic to not let it shudder.

My guess is that it's not the clutch itself but some narrowband resonance in the drivetrain/mountings.

 

[hondasash]

Thx for your advice so far

 

[watchdogd]

I use to experience with shuddering from an old Accord years ago, but coming from a GS-R and S2000 which never shuttered, I am surprised that such a nice car like the NSX would have that as a common behavior. I've only had my car about 1500 miles and gotten use to it, but also glad to hear and read that it's somewhat common .

 

[goldNSX]

I use to experience with shuddering from an old Accord years ago, but coming from a GS-R and S2000 which never shuttered, I am surprised that such a nice car like the NSX would have that as a common behavior. I've only had my car about 1500 miles and gotten use to it, but also glad to hear and read that it's somewhat common .

I'm not saying that the behaviour of the clutch is annoying or a design fault. I've just observed that even a broken-in new OEM clutch can shudder a little bit (not excessively!) if the circumstances are right:
- at certain revs in combination of throttle and intended acceleration etc.
- sometimes depends on clutch cold/warm
If I register some shudder while taking off from a full stop I just release the throttle or clutch pedal a little bit, it's already an automatic procedure to avoid it. So no problem at all. When I testdrove the car before buying it there was strong shudder every time you took off. That was not acceptable and the dealer had to change it.

 

[hondasash]

And what did the dealer to to change it?

 

[goldNSX]

And what did the dealer to to change it?

New (OEM) clutch.

 

[hondasash]

Just wanted to update you: Got installed a new clutch again (on warranty), now everything works fine.
No idea what the issue was, maybe the (old) new clutch ittself