skipdale

I have a different '08 Z06 tranny problem. There is a visible, not audible, vibration under loads in 5th gear. It vibtates forward and aft ~1mm about 5 times per second. Dealer has no awareness of the problem, although it has been reported on the forum by one other. She reported that GM had replaced 5th gear with no change, and that GM is now researching the issue before replacing 5th again, or replacing the tranny

JoesC5

I don't think GM understands the problem we have. When I say the car has the nibbles or grind when cold, I'm not talking ambient temp, I'm talking when the car hasn't got up to operating temp. The ambient may be 70 degrees, but the car is cold(not up to operating temp). I get the "cold" nibbles when it's 80 degrees ambient until the car gets up to operating temp. I have not driven my Z06 when the ambient was under 32 degrees. I have the nibbles everytime I cold start the car, no matter what the ambient temp is.

GM may say it is "normal" but my understanding of the word "normal" is that thay all should be that way, as it is the "norm". I guess that those that don't have the nibbles or grinds have an "abnormal" condition and should take their car in and have it repaired so that is is "normal"(ie. nibbles and grinds).

04Z16

The 32 degrees is exactly my complaint with GM. When my car is cold, not so much the weather but the car it grinds. When the temp is 70 or below the trans feels like I've got a granny gear and it keeps grinding until it is up to temp which may be 5 miles, or might be 20 miles depending on the ambient temperature.

GM threw together a service bulletin to appease and cover their A$$. GM needs to sh#$% or get off the pot. Maybe everyone who has the grind should flood the dealers with service requests and then send notice to the NHTSA to log complaints. Maybe someone will wake up and attempt a fix.

Quoted from my last visit to the dealer:
"C/S states vehicle has grind noise at first between 1-2 gears. Now is thru all the gears and worse when weather is colder. We are a second opinion, 9341 aware.
Drove vehicle and found has some noticeable grating on 1-2 shift and has a little abnormal (did not have like vehicle to compare to) grating into 3rd and 4th... was a little better when vehicle was warmer. Called TAC with Doc 2073364 and was advised probably will ot change if internals are replaced. Said to get with area rep and decide if they want to replace trans... with the intent that if it is the same cust. will be aware is a normal condition. Does in my opinion have a little objectional grating in 1-2 and into 3rd and 4th. Is not up to me will be area reps call, need to get the area rep."

Area rep did not want to replace the trans or rebuild the trans.

Thanks for the outstanding customer support GM. Documented that the trans did not feel right, area rep not even at the dealership and makes the call not to do anything with the trans.

How would everyone feel getting the car back with a write up like that??

RoatanMan

Are there any updates on any TSB's...? I only see this issue once in a while; knock wood...

NHRA95

For some strange reason my 08 LS3 Z51 never had this grinding problem when cold, but my 08 Z06 sure does.

FreeBoost

The T-56 in my '07 lasted less than 600 miles. It was so chewed up inside they didn't even try to fix it, just replaced it. The only reason GM change the trans for '08 is because the T-56 wasn't up to the task. Sounds like they exchanged one lemon for another lemon.

C66 Racing

If you use a fluid that meets their requirements, then they won't have a fit. The fluid recommended by AMSOIL for the C6 Z06 is the AMSOIL ATF which is the same fluid I'm currently using in my track duty C5 Z06 and my daily driver 06 CTS-V.

4wheels

If you used 100% Redline MTL on your fluid change, you used the wrong fluid. MTL is a bit too thick for these transmissions. Redline D4 ATF is the proper grade from Redline. If you do a lot of high speed or track driving, you can add up to 1/2 quart of MTL to D4 ATF increase the viscosity a hair & get more of the anti-wear/extreme-pressure additives, but any more and it will be somewhat tougher to shift.

04Z16

I've been looking and there was another post about a possible TSB from both Tremec and GM on this issue. The person posted it was due out in October or November, I can't find the post now was doing a search for it. Oh well, just killing time waiting for the BBB to set up the meet and greet with GM.

Hawkeye2

Bingo! Exactly like my 08 does. It does not matter what the outside temp is. The first few shifts it will grind 1 to 2. It does go away after
a period of driving.

I contacted a friend who owns a tranny shop, he told me GM's answer
about warming up synchros is hogwash! I just don't know if I want my
car at a dealership for an extended amount of time. No good will come of it. BTW it has 4,000 KM on it and has been babied. No hole shots,
no power shifts, just some spirited highway once in a while.

VicCaerter

Mine does the same crap and that is exactly how I would describe it.

04Z16

But just trust the General and give them another $34 Billion to continue screwing our eyes out.

WFO

My 08 daily driver Z with 9,800 miles has been performing great...seriously. Love this car.

I follow the old school muscle-car warm up...at least 100 degrees oil temp and then allow RPM's to rise above 2k mark. Shifts like I expect it would. Make sure your clutch is adjusted properly. Change out clutch fluid regularly as you see it get dark.

Like Vendors can do...mid stream change of parts and /or raw material suppliers, machining methodolgies, etc., all without notice. You/we/they end up finding out problematic issues later when they try to stop the bleeding on a problem. Hopefully someone in a decision making capacity will do the right thing.

Just an aside: Going off here. As part of any "Government bailout" might be, should be, to require automakers in need of same to get their product and service aligned with competition and nail down product and customer satisfaction approaching Malcolm Baldrige levels or better.

To do that you might have to change the work ethic from top to bottom. Senior execs with "out of whack" bonuses for non-performance and high priced labor. Better yet, instill more of a "performance" related bonuse structure..not the apathy encouraging high hourly rates that breed no creativity, motivation, thankless and crap attitudes that over payed execs and hostage holding Union jobs "might" tend to create.

Appreciation for having a great job and benefits is second to a company that actually can, make a profit. A place for investors/shareholders to invest, stocks that return on those investments. Then go back and hire/re-train the candidates that actually want to be there, that don't abuse sick leave and make excuses for less than the best they can do. Performance should be the rule.

But then, this is a whole other movie for another thread. Just my .00002 cents.

Thanks for the rant. I love this Forum.

TZ06

Mine is an 08 Z06 as well with the same problems plus once in a while
I experience slow clutch release which results in burned clutch smell.
I am driving shifters since almost 25 years but after exactly 988 miles
I still feel like a driver student sometimes not being able to do a proper
start with the car.
Had it in twice now. Both resulted in that they could not repeat the problems I reported.


Now here comes something new......
I picked the car up two days ago. After 2 miles while trying to shift
from 2nd to 3rd @ 1500 rpm I could not shift anymore.
The shift stick was completely stucked in neutral. I couldn't put any gear in. Clutch felt ok or at least not different.
Switched the engine off and still the same.
After more than 10 minutes my wife came... explained her what happened. She gets in the car and shifts every gear as smooth as you
could imagine.

The dealership picked the car up and promised to find the problem.

Has anyone here had this problem of a stucked shift stick ???

Shall keep you posted about my story.

04Z16

Sounds like a possible problem with the CAGS.

Daytona-flyer

I too have to be slow on the first and second time I shift from first gear. However after that it shifts fine.

Outside air temp. has little or no effect. It seems to be more of a lube issue. Once the fluid has a chance to move around a bit, it stops.

Eric

geezin56

I have an 08 z06, purchased 12/06 (don't know build date off hand). Same problem as others have reported. 1-2 shift grinds consistently after cold start and I'm generally shifting at fairly low rpm as there are a number of stop lights when I leave home. I've had this problem since I purchased the car a year ago. I haven't noticed that outside temp makes any difference. I'm the first to admit I'm most likely not what you'd call an "expert" when it comes to shifting, but have been driving man trans for over 12 years now and this one makes me feel (and sound) like a kid trying to learn to shift.

The 2-3 shift is somewhat "notchy", but I only feel/hear the grind when going from 1-2.

OneSickZ06

I had a slight grind when cold going from 1st to 2nd when the car had under 10K miles. Now it shifts good without any grind but you can still feel the gears seat together. My problem with the transmission has been the reverse. Grinds going into it every once and a while. PITA. The other problem I've had is with the driver seat leather. It keeps unstiching itself. they are going to replace it one more time and we'll see how it goes.

Tom Beames

My 07Z did the same thing-grind at 1 to 2 and again at 3 to 4. It would stop once the trans. fluid would warm up. I watched the oil temp gauge as a CF member ("Ranger") suggested and when the engine oil was in normal operating temp. I could assume that that the trans. oil was "warmed" up. It worked but remained very frustrating. I subsequently traded the car for a Suburban and bought an 04Z. LOVE the car and NO trans. problems. BUT, I do miss the 505HP!!!!!

Tom Beames
GR8KAR

2MuchRiceMakesMeSick

Anyone with this problem install a MGW shifter?