:yesnod: 
ZF Tranny Concern !!!
Thread Starter
Instructor
Joined: Sep 2000
Posts: 163
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From: Toronto, Ontario,Canada
ZF Tranny Concern !!!
Without further due I would like to announce the purchase of my second corvette, a 1992 torch red on gray 6 spd.
I’m attempting to source out a problem with my ZF tranny…I think! (I’m still use to my 4+3)
1) in reverse I hear a wind / clunck but not the typical whine of reverse and
2) I hear that same sort of whine slowing down in 1st gear from time to
time
3) In the stop position shifting from 1st to 2nd sounds kinda clunky.
Over all the tranny is solid !!!!
With an oil change on the tranny…what would you recommend? I've been told stick with the ZF oil @ $34.00 L Canadian...ouch......
Please bear in mind that I just made the switch from a 4+3 to a ZF, so call me paranoid if you must... but I’m somewhat concerned…has anyone heard such noises before?
Thanks,
Mark
:cheers:
[Modified by mschevous85, 7:29 AM 5/23/2002]
[Modified by mschevous85, 9:03 AM 5/23/2002]
I’m attempting to source out a problem with my ZF tranny…I think! (I’m still use to my 4+3)
1) in reverse I hear a wind / clunck but not the typical whine of reverse and
2) I hear that same sort of whine slowing down in 1st gear from time to
time
3) In the stop position shifting from 1st to 2nd sounds kinda clunky.
Over all the tranny is solid !!!!
With an oil change on the tranny…what would you recommend? I've been told stick with the ZF oil @ $34.00 L Canadian...ouch......
Please bear in mind that I just made the switch from a 4+3 to a ZF, so call me paranoid if you must... but I’m somewhat concerned…has anyone heard such noises before?
Thanks,
Mark
:cheers:
[Modified by mschevous85, 7:29 AM 5/23/2002]
[Modified by mschevous85, 9:03 AM 5/23/2002]
Team Owner
Joined: Mar 1999
Posts: 89,144
Likes: 3
From: Life's tough, wear a helmet.
Re: ZF Tranny Concern !!! (mschevous85)
The ZF is a loud tranny. I don't have any clunking but the gear whine in reverse and first is quite loud. Your sounds are probably normal but without hearing them first hand I can't be 100% positive.
As for fluid change - my recommendation is to stick with the stock recommended fluid. You'll get other suggestions to go with a Red Line or some other product. Personally, I wouldn't do it. I stick with the stock recommendation. I think I have a part # for the fluid around somewhere. I'll see if I can dig it up.
As for fluid change - my recommendation is to stick with the stock recommended fluid. You'll get other suggestions to go with a Red Line or some other product. Personally, I wouldn't do it. I stick with the stock recommendation. I think I have a part # for the fluid around somewhere. I'll see if I can dig it up.
Burning Brakes
Joined: Sep 2001
Posts: 1,011
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From: Jupiter Florida
Re: ZF Tranny Concern !!! (Scoob)
Team Owner
Joined: Mar 1999
Posts: 89,144
Likes: 3
From: Life's tough, wear a helmet.
Re: ZF Tranny Concern !!! (rocketfinger)
Great link, rocketfinger!
DURABILITY:
The ZF S6-40 test program for design acceptance for release into production was defined by General Motors Uniform Test Standard (GMUTS) R15-6. This involved 15,000 miles of full-throttle up-shifts at engine redline and downshifts to redline. This was done mostly up and down a 7.2 percent grade on the GM Proving Ground In Milford, Mich., and included
wide-open-throttle runs uphill in reverse!
Another test involved 200,000 highway and proving ground test miles, while still another test involved about 80 hours of high-speed testing on various racetracks and at the GM Desert Proving Ground in Mesa, Ariz. This was followed up by a thousand miles of testing on the high banks at Talladega Super Speedway in Alabama.
:eek: :eek:
DURABILITY:
The ZF S6-40 test program for design acceptance for release into production was defined by General Motors Uniform Test Standard (GMUTS) R15-6. This involved 15,000 miles of full-throttle up-shifts at engine redline and downshifts to redline. This was done mostly up and down a 7.2 percent grade on the GM Proving Ground In Milford, Mich., and included
wide-open-throttle runs uphill in reverse!
Another test involved 200,000 highway and proving ground test miles, while still another test involved about 80 hours of high-speed testing on various racetracks and at the GM Desert Proving Ground in Mesa, Ariz. This was followed up by a thousand miles of testing on the high banks at Talladega Super Speedway in Alabama.
:eek: :eek:
Burning Brakes
Joined: Sep 2001
Posts: 1,011
Likes: 0
From: Jupiter Florida
Re: ZF Tranny Concern !!! (Scoob)
...included
wide-open-throttle runs uphill in reverse!
wide-open-throttle runs uphill in reverse!
Well...I was trying to think of something interesting to do with my lunch hour...
[Modified by rocketfinger, 4:34 PM 5/23/2002]
Team Owner
Joined: Oct 1999
Posts: 31,977
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From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
Re: ZF Tranny Concern !!! (rocketfinger)
I understand the BMW fluid is synthetic. Yes be very careful shallow clutching. The ZF is a noisy trans. with the 94 and earlier being the noisiest.
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Team Owner
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From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
Re: ZF Tranny Concern !!! (Paul G)
Power shifting is shifting without letting off the gas. Shallow clutching is not going full travel on the clutch. The two combined make for busted synchros if you screw up and the cltuch does not go for enough or is let out to quick.
Burning Brakes
Joined: Nov 2001
Posts: 1,241
Likes: 9
From: Houston TX
Re: ZF Tranny Concern !!! (mschevous85)
the hydraulic clutch actuation is less than perfect. there is lag. there are tricks to help, but i'm not convinced any are good fixes.
as for the rhythmic whine in 1st/reverse, this is an artifact of the dual-mass flywheel, as far as i can tell. it must be winding up and releasing, as it seems to happen more on cars with high mileage and/or abused flywheels.
as for the rhythmic whine in 1st/reverse, this is an artifact of the dual-mass flywheel, as far as i can tell. it must be winding up and releasing, as it seems to happen more on cars with high mileage and/or abused flywheels.
Drifting
Joined: Apr 2000
Posts: 1,803
Likes: 1
From: PA
Re: ZF Tranny Concern !!! (MSR)
Clunking with clutch depressed is symptomatic of low hydraulic clutch fluid. Sounds like your clutch is not fully disengaging. You should check clutch fluid level yearly and replace the master and slave unit if there is seepage or fluid loss. This is the one thing that will destroy a ZF (aside from powershifting or inappropriate trans fluid). I can not believe GM is selling the original ZF spec tranny fluid in Canada for $34/quart. It can be ordered for $8 US funds at absolutely ANY GM dealer (Cadillac, Saturn etc).
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: ZF Tranny Concern !!! (Rick93Z07)
the whine in 1st gear is caused by the cut of the gears... they are straight cut.
also, BMW makes a synthetic 10-60 gear oil that they used in the ZF6 when the tranny was used by BMW in the 850i...
congrats on the new Vette!!! I am kinda partial to the 92.. :)
[Modified by bogus, 4:33 PM 5/23/2002]
also, BMW makes a synthetic 10-60 gear oil that they used in the ZF6 when the tranny was used by BMW in the 850i...
congrats on the new Vette!!! I am kinda partial to the 92.. :)
[Modified by bogus, 4:33 PM 5/23/2002]
Team Owner
Joined: Apr 2001
Posts: 22,267
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From: Dallas TX
Re: ZF Tranny Concern !!! (Scoob)
Great link, rocketfinger!
DURABILITY:
The ZF S6-40 test program for design acceptance for release into production was defined by General Motors Uniform Test Standard (GMUTS) R15-6. This involved 15,000 miles of full-throttle up-shifts at engine redline and downshifts to redline. This was done mostly up and down a 7.2 percent grade on the GM Proving Ground In Milford, Mich., and included
wide-open-throttle runs uphill in reverse!
Another test involved 200,000 highway and proving ground test miles, while still another test involved about 80 hours of high-speed testing on various racetracks and at the GM Desert Proving Ground in Mesa, Ariz. This was followed up by a thousand miles of testing on the high banks at Talladega Super Speedway in Alabama.
:eek: :eek:
DURABILITY:
The ZF S6-40 test program for design acceptance for release into production was defined by General Motors Uniform Test Standard (GMUTS) R15-6. This involved 15,000 miles of full-throttle up-shifts at engine redline and downshifts to redline. This was done mostly up and down a 7.2 percent grade on the GM Proving Ground In Milford, Mich., and included
wide-open-throttle runs uphill in reverse!
Another test involved 200,000 highway and proving ground test miles, while still another test involved about 80 hours of high-speed testing on various racetracks and at the GM Desert Proving Ground in Mesa, Ariz. This was followed up by a thousand miles of testing on the high banks at Talladega Super Speedway in Alabama.
:eek: :eek:
[Modified by Glock'94, 4:21 PM 5/23/2002]
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: ZF Tranny Concern !!! (rocketfinger)
...included
wide-open-throttle runs uphill in reverse!
:eek:
Well...I was trying to think of something interesting to do with my lunch hour...
[Modified by rocketfinger, 4:34 PM 5/23/2002]
wide-open-throttle runs uphill in reverse!
:eek:
Well...I was trying to think of something interesting to do with my lunch hour...
[Modified by rocketfinger, 4:34 PM 5/23/2002]
Team Owner
Joined: Oct 1999
Posts: 31,977
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From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
Re: ZF Tranny Concern !!! (Bob Mosaic)
How many quarts does it hold, and what is the part #?
Thank you very much,
Robert
Thank you very much,
Robert
Le Mans Master
Joined: Nov 1999
Posts: 7,687
Likes: 2
From: San Antonio TX
Re: ZF Tranny Concern !!! (Scoob)
Great link, rocketfinger!
DURABILITY:
The ZF S6-40 test program for design acceptance for release into production was defined by General Motors Uniform Test Standard (GMUTS) R15-6. This involved 15,000 miles of full-throttle up-shifts at engine redline and downshifts to redline. This was done mostly up and down a 7.2 percent grade on the GM Proving Ground In Milford, Mich., and included
wide-open-throttle runs uphill in reverse!
Another test involved 200,000 highway and proving ground test miles, while still another test involved about 80 hours of high-speed testing on various racetracks and at the GM Desert Proving Ground in Mesa, Ariz. This was followed up by a thousand miles of testing on the high banks at Talladega Super Speedway in Alabama.
:eek: :eek:
DURABILITY:
The ZF S6-40 test program for design acceptance for release into production was defined by General Motors Uniform Test Standard (GMUTS) R15-6. This involved 15,000 miles of full-throttle up-shifts at engine redline and downshifts to redline. This was done mostly up and down a 7.2 percent grade on the GM Proving Ground In Milford, Mich., and included
wide-open-throttle runs uphill in reverse!
Another test involved 200,000 highway and proving ground test miles, while still another test involved about 80 hours of high-speed testing on various racetracks and at the GM Desert Proving Ground in Mesa, Ariz. This was followed up by a thousand miles of testing on the high banks at Talladega Super Speedway in Alabama.
:eek: :eek:
Pro
Joined: Feb 2001
Posts: 662
Likes: 0
From: Denver CO
Re: ZF Tranny Concern !!! (mschevous85)
Thanks for the help with the part #!!!
One morre question about a DM flywheel...Should it be able to turn about 1/8 to 1/4 of a turn with minimal effort before the motor begins to spin? I thought I had a problem with the PP, but I believe it is a problem with the flywheel. I can rotate the machine piece of the flywheel a little before they motor even spins...IS this OK????? Or do i need a new flywheel???
Help please,
Robert
One morre question about a DM flywheel...Should it be able to turn about 1/8 to 1/4 of a turn with minimal effort before the motor begins to spin? I thought I had a problem with the PP, but I believe it is a problem with the flywheel. I can rotate the machine piece of the flywheel a little before they motor even spins...IS this OK????? Or do i need a new flywheel???
Help please,
Robert
