All right so heres the deal, saturday we swapped the 10-bolt out for a moser 12-bolt, rebuilt the tranny, bearings, syncros, everything, new umi torque arm, spec 4. Alotta work and changes all at once. So heres the thing sitting still with the clutch out theres chatter, its allways been there as long as ive owned the car (3-yrs). Push the clutch in it goes away, let it out and right back to chattering. Next problem, when im under 2k in any gear, it vibrates/growls violently under acceleration. stops over when you climp over 2k. Below 2k under throttle vibration/growls. under 2k off the throttle nothing. everything in the tranny is new, we pulled it back out tore it open again and found nothing, everything looked great. Any suggestions?

 

Nobody?

 

I am also interested, have very simular noise at same rpms . Someone told me it has something to do with flywheel/clutch assembly balancing or bad pilot bushing. But my guess - something in tranny. Is it growls less when it's cold (mine do this)?

 

In my experience, your first problem (chattering in neutral with clutch out) is the throwout bearing rattling against the clutch fork. It goes away when you push in the pedal because the fork begins applying pressure to the TO bearing and stops it from rattling. Very common even with new TO bearings. I've had stock, SPEC, and SLP clutches (with new TO bearings) that have all done this to varying degrees. No known solution that I've seen or heard of yet...just one of minor annoyances you learn to "tune out" over time.

Your second problem (groaning & other assorted tranny noises under load at low rpms) is also very common and "just one of those things". Yours does sound worse than normal though....do you have an aftermarket shifter? If so, these always amplify the tranny noises. Mine does the same thing and got much worse when I put in a shifter (Pro 5.0). It's still there but I made it much better by lining the inside of the shift boot with Dynamat (sound deadening material) and slipping an O-ring over the bolts that mount the shifter handle to the base. These 2 things quieted everything down considerably, but it is still there and still noticeable. Unfortunately, I haven't seen or heard of a solid "fix" for this either. Seems to be normal with the T56...

 

Well I could understand, the t/o against the clutch fork. Ive actually thought that. Now for the shifter thing i think thats BS, Ive had the same shifter since ive owned the car but i have never seen heard this till i rebuilt the tranny. It is a spec 4 clutch think that has something to do with it? Thats the only thing changed other than the tranny rebuild (in the tranny wise) . We pulled the tranny back out and tore it down again just to make sure, but still nothing.

 

People will tell you pilot bearing, throwout bearing, or the heavy duty nature of the tranny itself. No one seems to have a clear solution, but most everyone agrees its ‘cosmetic’ and doesn’t indicate a durability problem.

I never had noise with the clutch out in neutral, but i always had a decent tranny groan @~1200 rpms with the stock clutch. Last year I put in a new street twin with Al flywheel. I replaced the pilot bushing with a new pilot bearing (the 6.2l diesel one that works) as a cheap attempt to fix this. The throwout bearing was new with the new clutch also. I hoped this would take care of it, but it didn’t. I have the same old groan, just now at ~1700 rpms instead. I just changed the mass of the flywheel, clutch, and other rotating parts, so a different harmonic frequency isn’t that surprising.

My cousin’s C5 has made a very similar groan around 1000 rpms since practically new. That car has an obviously different clutch setup and the T56 is mounted on the rear transaxle instead of the motor bellhousing. That makes me scratch my head even more.

Since i'm not a fan of pulling the tranny, paying for rebuilds, and lining up a dual disc clutch for re-intall..... I’ve just come to accept it, to cherish it, to love it.

Good luck,
-Brent

 

The more i drive it the more i think its the nature of the clutch, Ive never had a clutch this harsh (spec 4). I think the groan is the clutch, but it is outrageous of the way it sounds. Maby when the clutch finishs its break in cycle it will clear up a lil bit. As far as the neutral thing im just gonna suck it up and live with it i guess.

 

Believe it.
Your right on the point with the TOB rattle noise.
The growling is very normal for T56 and is made worse with the addition of an aftermarket shifter. The stock shifter is heavily is full of rubber and dampened to reduce the noise. A rubber or cork gasket under the aftermarket shifter will help. This noise is normal and harmless, just annoying.
The growl mine makes is louder when my hand is on the shifter, if I release it it gets quieter.

 

Mine is def. T56 problem. After changing my trans. fluid to Mobil-1 it was like 50% louder and growl so much, it scared innocent drivers around
Replaced fluid with Royal Purple Synchromax - it's much better now, noise is at a level, I had with regular synchromesh before.
Edit: and I have Pro 5.0 with no gaskets, except some RTV under it.

 

my car is the same way. I think its a combination of normal T56 issues and sub-par spec quality (my spec 3 chatters like crazy with about 2k on it).

 

My car does the same exact thing, under 2k rpm. It sounds like marbles in a can and it gets pretty loud, loud enough to hear outside the car. But if you keep the rpms up in the proper gear at all times you wont hear it much. I can hear it if I put it in 3rd when going 10mph and give it 25%-50% throttle.

 

My T56 on my WS6 has always done that growling noise. in 1st and 2nd at low RPM's. Heavy load makes it worst. My dad has a 03 Cobra with a T56 and his is even louder inside.