ZF six speed problem
06-25-2018, 01:15 PM
#21
Race Director
Weird.
for me he had me take a measurement with calipers and give him the measurement.
a few weeks later i got a new shim that measured several thousandths of an inch thicker, and a new end plug to replace the one i had to pull to get out the shim.
i made my reply because i didnt want the OP to try the shim (and not be thick enough) and then claim the shimming doesnt work.
On a sidenote:
zfdoc is a great guy but im not sure how much time he still devotes to his job repairing the zf anymore.
for me he had me take a measurement with calipers and give him the measurement.
a few weeks later i got a new shim that measured several thousandths of an inch thicker, and a new end plug to replace the one i had to pull to get out the shim.
i made my reply because i didnt want the OP to try the shim (and not be thick enough) and then claim the shimming doesnt work.
On a sidenote:
zfdoc is a great guy but im not sure how much time he still devotes to his job repairing the zf anymore.
06-25-2018, 03:13 PM
#22
Weird.
for me he had me take a measurement with calipers and give him the measurement.
a few weeks later i got a new shim that measured several thousandths of an inch thicker, and a new end plug to replace the one i had to pull to get out the shim.
i made my reply because i didnt want the OP to try the shim (and not be thick enough) and then claim the shimming doesnt work.
On a sidenote:
zfdoc is a great guy but im not sure how much time he still devotes to his job repairing the zf anymore.
for me he had me take a measurement with calipers and give him the measurement.
a few weeks later i got a new shim that measured several thousandths of an inch thicker, and a new end plug to replace the one i had to pull to get out the shim.
i made my reply because i didnt want the OP to try the shim (and not be thick enough) and then claim the shimming doesnt work.
On a sidenote:
zfdoc is a great guy but im not sure how much time he still devotes to his job repairing the zf anymore.
Last edited by TheGreek!; 06-25-2018 at 03:16 PM.
06-27-2018, 05:56 PM
#24
IMHO - your comment that it's quieter when cold is quite telling. Most likely the oil in the tranny is thicker when it's colder - and that is doing a better job of keeping the gear noise in check.
Point 1 - pulling the ZF gearbox is NOT a fun job - I've done it more than once and while there are some tricks that make the job a bit easier - the ZF box weighs over 125 LB, and there is nothing flat on the underside of the ZF tranny to let it lie flat on a tranny jack.
Look - you know the Previous Owner changed the clutch - so it's likely that he changed the trans fluid as well - who knows what fluid is in the box now ... Drain it out - and replace with something like Redline, Amsoil, or whatever fluid you prefer - as I said in my reply to your other post - do some searching on this forum about fluid choices - lots of info out there - but If I were you - I'd stay with the thicker fluids as they will help attenuate the gear noise - but without a DMF - don't expect the tranny to be quiet - it ain't gonna happen - particularly when the fluid is "warm".
Point 1 - pulling the ZF gearbox is NOT a fun job - I've done it more than once and while there are some tricks that make the job a bit easier - the ZF box weighs over 125 LB, and there is nothing flat on the underside of the ZF tranny to let it lie flat on a tranny jack.
Look - you know the Previous Owner changed the clutch - so it's likely that he changed the trans fluid as well - who knows what fluid is in the box now ... Drain it out - and replace with something like Redline, Amsoil, or whatever fluid you prefer - as I said in my reply to your other post - do some searching on this forum about fluid choices - lots of info out there - but If I were you - I'd stay with the thicker fluids as they will help attenuate the gear noise - but without a DMF - don't expect the tranny to be quiet - it ain't gonna happen - particularly when the fluid is "warm".
06-27-2018, 09:54 PM
#25
Intermediate
IMHO - your comment that it's quieter when cold is quite telling. Most likely the oil in the tranny is thicker when it's colder - and that is doing a better job of keeping the gear noise in check.
Point 1 - pulling the ZF gearbox is NOT a fun job - I've done it more than once and while there are some tricks that make the job a bit easier - the ZF box weighs over 125 LB, and there is nothing flat on the underside of the ZF tranny to let it lie flat on a tranny jack.
Look - you know the Previous Owner changed the clutch - so it's likely that he changed the trans fluid as well - who knows what fluid is in the box now ... Drain it out - and replace with something like Redline, Amsoil, or whatever fluid you prefer - as I said in my reply to your other post - do some searching on this forum about fluid choices - lots of info out there - but If I were you - I'd stay with the thicker fluids as they will help attenuate the gear noise - but without a DMF - don't expect the tranny to be quiet - it ain't gonna happen - particularly when the fluid is "warm".
Point 1 - pulling the ZF gearbox is NOT a fun job - I've done it more than once and while there are some tricks that make the job a bit easier - the ZF box weighs over 125 LB, and there is nothing flat on the underside of the ZF tranny to let it lie flat on a tranny jack.
Look - you know the Previous Owner changed the clutch - so it's likely that he changed the trans fluid as well - who knows what fluid is in the box now ... Drain it out - and replace with something like Redline, Amsoil, or whatever fluid you prefer - as I said in my reply to your other post - do some searching on this forum about fluid choices - lots of info out there - but If I were you - I'd stay with the thicker fluids as they will help attenuate the gear noise - but without a DMF - don't expect the tranny to be quiet - it ain't gonna happen - particularly when the fluid is "warm".
06-28-2018, 07:21 AM
#26
Race Director
Its my belief the dual mass flywheel is a heavy, performance robbing POS which is better suited as a boat anchor.
This heavy flywheel falls in with the l98 TPI low end TQ / other philosophies that GM has since abandoned.
the car is not a cadillac
This heavy flywheel falls in with the l98 TPI low end TQ / other philosophies that GM has since abandoned.
the car is not a cadillac
06-28-2018, 06:28 PM
#27
Sure...
1. Get the car up in the air - try to get the car a good foot in the air. Having the car way up in the air also helps to be able to tilt the tranny more aggressively to allow the shift lever to clear the body.
2. The "C" Beam (a.k.a. Torque arm) is not fun to remove - but if you pull the two bolts that hold the "batwing" (a.k.a. the rear diff mount) in place - the angles get a lot better to deal with. (Put a jack under the diff to control the rear diff assembly while doing this).
3. If the tranny comes out - but the bellhousing just doesn't want to come off - it could be that the release bearing is holding things up (this frequently happens with very worn clutch discs). If that is the case - pop the little cover that's installed over the rear access to the pivot ball. Use an allen wrench (12mm ???) to "unscrew" that pivot ball (remember - you're working backwards - so unscrewing from the back is "tightening". Once the pivot ball is unscrewed - the bellhousing should come right off.
4. The shift **** sounds like something that should be very easy to remove - sometimes that is NOT the case - I once had to cut one off with a hacksaw. Once you pop the plastic piece with shift pattern label - you will see a "square" metal pin that has to be removed in order to unscrew the shift know. That pin has to come straight Up (as in towards the car's roof). Sometimes small vice grips will get it out.- if not try drilling and tapping it - screwing in a bolt and prying it out that way..
1. Get the car up in the air - try to get the car a good foot in the air. Having the car way up in the air also helps to be able to tilt the tranny more aggressively to allow the shift lever to clear the body.
2. The "C" Beam (a.k.a. Torque arm) is not fun to remove - but if you pull the two bolts that hold the "batwing" (a.k.a. the rear diff mount) in place - the angles get a lot better to deal with. (Put a jack under the diff to control the rear diff assembly while doing this).
3. If the tranny comes out - but the bellhousing just doesn't want to come off - it could be that the release bearing is holding things up (this frequently happens with very worn clutch discs). If that is the case - pop the little cover that's installed over the rear access to the pivot ball. Use an allen wrench (12mm ???) to "unscrew" that pivot ball (remember - you're working backwards - so unscrewing from the back is "tightening". Once the pivot ball is unscrewed - the bellhousing should come right off.
4. The shift **** sounds like something that should be very easy to remove - sometimes that is NOT the case - I once had to cut one off with a hacksaw. Once you pop the plastic piece with shift pattern label - you will see a "square" metal pin that has to be removed in order to unscrew the shift know. That pin has to come straight Up (as in towards the car's roof). Sometimes small vice grips will get it out.- if not try drilling and tapping it - screwing in a bolt and prying it out that way..
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mvettewhite (06-29-2018)
06-28-2018, 06:32 PM
#28
06-28-2018, 06:37 PM
#29
If it were up to me - all Vettes would come with the Z51 handling package - and if you don't like the ride - Tough **** - the Cadillac dealer is just down the street - but that is NOT how the GM execs feel....
06-28-2018, 07:04 PM
#30
Team Owner
Pro Mechanic
Everyone has focused in on the elements that cause the "ZF RATTLE"....but that is a rattle. Are we sure that's the problem?
I think the problem may be something else. ZF rattle doesn't typically happen when underway/under load. And trans whine should diminish in higher gears....with none in 4th gear. I think it's something else.
06-28-2018, 08:24 PM
#31
Everyone has focused in on the elements that cause the "ZF RATTLE"....but that is a rattle. Are we sure that's the problem?
I think the problem may be something else. ZF rattle doesn't typically happen when underway/under load. And trans whine should diminish in higher gears....with none in 4th gear. I think it's something else.
I think the problem may be something else. ZF rattle doesn't typically happen when underway/under load. And trans whine should diminish in higher gears....with none in 4th gear. I think it's something else.
06-28-2018, 08:50 PM
#32
Team Owner
Pro Mechanic
This might help; here is my car. '92 LT1/ZF6. This sound is pretty normal. Is this the sound that you're talking about? NOTE: right at the beginning of the vid where I start from a stop, then listen at 0:30 when I go WOT in frst gear.
Last edited by Tom400CFI; 06-28-2018 at 08:51 PM.
06-28-2018, 10:28 PM
#33
This might help; here is my car. '92 LT1/ZF6. This sound is pretty normal. Is this the sound that you're talking about? NOTE: right at the beginning of the vid where I start from a stop, then listen at 0:30 when I go WOT in frst gear.
https://youtu.be/Qt_wwhModG8
https://youtu.be/Qt_wwhModG8
06-28-2018, 11:15 PM
#34
I run the Fidanza ALFW with a Stage II Carolina sprung hub clutch; pretty much what you have.
I will bet $100 zf doc will tell you that aluminum FW is the cause of that rattle and he will recommend his shim to solve the problem; or of course finding an EOM stock dual mass FW. There is a huge difference in quietness in the dual mass (in any gear, any speed, w or w/o clutch engaged).
I will bet $100 zf doc will tell you that aluminum FW is the cause of that rattle and he will recommend his shim to solve the problem; or of course finding an EOM stock dual mass FW. There is a huge difference in quietness in the dual mass (in any gear, any speed, w or w/o clutch engaged).
Last edited by 856SPEED; 06-28-2018 at 11:16 PM.
06-28-2018, 11:45 PM
#35
Team Owner
Pro Mechanic
^ OP didn't say he had a rattle...he said he had a buzzing sound while accelerating. That's not "ZF rattle", as far as I understand it.
For real? Did you listen right at 0:30 when I hit it? Loudest thing in the car for the first 3-4 seconds is the trans. (?)
For real? Did you listen right at 0:30 when I hit it? Loudest thing in the car for the first 3-4 seconds is the trans. (?)
Last edited by Tom400CFI; 06-28-2018 at 11:46 PM.
06-29-2018, 12:33 AM
#36
Maybe its the speakers in my laptop but all I hear is the engine and what sounds like wind noise or something. Were you driving with the windows open? Either way I don't hear any trans noise, at least not the noise that I hear from my trans anyway.
06-29-2018, 12:35 AM
#37
Team Owner
Pro Mechanic
06-29-2018, 08:44 AM
#38
semantics...rattle.....buzz....people describe things in their own way. I run that set up and very familiar with what his experiences are, or at least I believe so....we shall see what ZF doc says....aluminum single mass FW’s really let you hear all kinds of noises....and it’s loud...nothing like your video, I can tell ya..
06-29-2018, 11:18 AM
#39
Team Owner
Pro Mechanic
Copy that. 
06-29-2018, 03:19 PM
#40
BTW;
another option is to move the idle speed up until the noise is minimal....that’s where mine was annoying...w/o the clutch engaged.
I moved my idle speed up to 1,000 RPM which nearly eliminated the “ rocks in a can” sound w/o the clutch engaged...Now, I run a Holley HP ECM making that adjustment much easier.... but with my cam, the idle is smooth...just not as lumpy like it used to be...
another option is to move the idle speed up until the noise is minimal....that’s where mine was annoying...w/o the clutch engaged.
I moved my idle speed up to 1,000 RPM which nearly eliminated the “ rocks in a can” sound w/o the clutch engaged...Now, I run a Holley HP ECM making that adjustment much easier.... but with my cam, the idle is smooth...just not as lumpy like it used to be...
Last edited by 856SPEED; 06-29-2018 at 03:19 PM.