Transmission issues 06 Z06?

[Sirped]

I am just wondering if any of you out there with the new Z06 are hearing a type of grinding noise while slow excelleration in first gear? It's only during low RPM gas on and then goes away. I have only put 300 easy miles on the car so far. Thanks.

[navyasw02]

That's just the way they sound. There are a few articles posted about it already. I thought the same thing when I first got it, but it sounds better after you put some more miles on it and after a while you dont notice it anymore anyway. Just think of it as the car telling you it wants to go faster...

[JCEng]

Normal. It's actually an internal vibration known as "gear rattle" in the industry. The BW/Tremec T56 simply exhibits this character- many gearboxes have throughout the years - typically larger, higher capacity ones at that. Remember, your box has to handle nearly 500 ft-lbf of input torque! There are very few transmissions this strong out there - probably a market opportunity for someone.

Since it's actually a vibration, various measures can be taken to deal with it - a dual-mass flywheel is the most common. (That actually means a layer of rubber in steel "sandwich" that literally absorbs torsional movement.) Chevy tried this on the C6 but gained tenths on acceleration times. The performance loss wasn't worth it. Sometimes tighter clearances (and tolerances) can help - but that may be beyond Tremec's capability - and sometimes the relationships between rotating masses/inertias, stiffnesses and geometries involved in a particular gearbox configuration just are predisposed to this condition (I suspect that here).

No worries!

[clogan]

It's normal. My two previous Mustang Cobras did the same thing.

No worries.

CW

[c6zdude]

I was under the impression it was inherent to the front engine / rear transmission layout, called "power train lash" or something like that. Porsche 944s with the same layout suffer from it as well. Situation normal.

[jrz1]

I recently began hearing a clunking noise intermittently when driving slowly in first gear. Sounds like transmission problems. It was not there for the first 3500 miles. It's in the rear and almost sounds like suspension creaking but I think it's transmission related clunking in first gear only. It is not normal. I may take the car in soon if I hear it again.

[06ZO6]

see Dragging Sound thread ... thanks for the info -- this seems to answer the questions I have been posting on that thread with no response.

[Sirped]

Thanks guys, makes me feel a lot better. KP

[jrz1]

Took car in. Tech thinks the noise is related to a service bulletin out which says to check differential (I think it was the differential) fluid level/change fluid and add an additive. Makes more noise when cold so they wanted to keep overnight to check again in the AM after changing fluid.

[Tony Skarbic]

COLD, where are you at? It's 118 here in sunny California.

[jrz1]

its a relative term. I'm in Charlotte NC and "cold" in the AM is probably 75.

[smook]

No rattle here! Hot or Cold.



-zBill.