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Six Speed Transmission Problem

R

RP96

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I have an LT4 with a six speed transmission. There is only 10,000 miles on the car. In fifth and sixth gear, starting at about 65 mph, the transmission sings, and it is not a pretty song. The whining only happens under load. If you let up on the throttle, it goes away. I suspect that it is a bearing on the 5th/6th gear shaft. Has anyone had a similar problem? Anybody have any luck with GM fixing it out of warranty? Thanks.
 
GOOD LUCK! Mine has problems too... it whines when it is cold... try a fluid change to sythetic... I have had good experiences with Mobil 1 (i am going to change it in mine soon)... GM may do something for you if you are the first owner of the car... otherwise they usually don't do anything
 
Yes, I have this problem too,
and I always have. (bought
car 5 yrs old, 42k mi).

Let us know if you find a fix!
 
Check out www.zfdoc.com. Bill Boudreau is an expert on the ZF transmissions. He rebuilds them and can give you some excellent advise. Note also his findings/recomendations for lubricants. Mobil 1 is not a good choice.

Dennis
Grand Sport #598
 
I looked at his website, and it didn't mention a whole lot about the tranny oil... I have used mobil 1 in my last vette, and the shifting was noticably smoother, the interior of the car by my right leg was cooler... I had over 100k on the car when i sold it with no problems.
 
6 speed noise

Watch out for the dealers. Mine was useless. My noise is not the same as yours, I took it to my local Chevy dealer who then gave me three options, Buy a new tranny for $6K, buy a rebuilt
for $4K, or remove it and ship it out for repair. The thing that upset me was they wouldn't even attempt to tell me what was wrong with it. Told me "yep you got a noise" Said that Chevy doesn't even want the dealer to work on them. Good Luck.
P.S Bill at ZF was a lot of help, take Dennis's advice. Turned out there was a fourth option, it is just a noise, there is no catastrophic failure waiting to occur, my tranny will last a long long time and I can spend that $6K on something else.
 
e-mail Bill Boudreau

Check out his web-site once again.. if the answer to your problem is not already on there, send him an e-mail describing the problem you're having. He will respond both quickly and completely. He tells you on his web-site the information about your car that he requires.
I too have just had a tranny/flywheel noise problem that he has helped diagnose. I found him to be ultra helpful, knowledgeable and much appreciated his experienced input (as did my mechanic !). Over the last 8 years, he's fixed more than 90 tranny's and has spent in excess of 6000 hours..... he knows his stuff!!
 
If I remember correctly, the ZF-6 is baised on a race tranny, and by nature it rather noisy. Its just the way it was designed. I seem to remember that in '93 there was a slight re-design of the tranny because of all the complaints Chevy was getting about it being so noisy. They reduced the noise of the tranny, but in doing so, also slightly reduced the power raiting. It is still failry noisy even though.

Jason
 
they did try to make it quieter, but I think the quieter/weaker tranny came in '94, i think it was they eliminated the reverse lockout at the same time of the redesign, and i know 93 has the lockout
 
RP96 said:
I have an LT4 with a six speed transmission. There is only 10,000 miles on the car. In fifth and sixth gear, starting at about 65 mph, the transmission sings, and it is not a pretty song. The whining only happens under load. If you let up on the throttle, it goes away. I suspect that it is a bearing on the 5th/6th gear shaft. Has anyone had a similar problem? Anybody have any luck with GM fixing it out of warranty? Thanks.

**please note: that this was a feeble attempt @Humor.........
Yes, and here is how you cure two problems w/ one bullet.......first you change the exhaust to a performance exhaust see ( http://corvetteactioncenter.com/forums/showthread.php?s=&threadid=14730 )............and that makes the whine go away. It also eliminates the problem of the cd player only accepting one cd..............the music is comin from under the front clip
:grinshot :grinshot
 

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