Transmission Rattle??
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
Transmission Rattle??
This may be a very dumb question but is there anything in a manual transmission that can rattle or knock? My buddy has a 90 with a 6 speed and there seems to be an inconsistent knock coming from the tranny. The tranny shifts and drives great. I always thought that there are only gears in a manual that wouldnt really make a sound like this. Thanks!
Last edited by jimmers; May 28, 2007 at 10:36 PM.
Melting Slicks
Joined: Dec 2004
Posts: 3,285
Likes: 51
From: Jacksonville, FL
St. Jude Donor '08 thru '26
The 90 zf6's make a bunch of noise, in first thru fourth, a lot of whine from the straight(or nearly straight) cut gears. Also in neutral sometimes they sound like they have rocks rolling around in there. The D/M fly wheel will also make slight knocking noises if the motor isn't exactly smooth at idle. The D/M also starts knocking a bit when the springs are going south but usually those springs last for 100K miles before they go south.
Overall my 90's 6spd sounds a lot like my old M22 from my C3 only a bit louder. I'd venture a guess to say that what you hear might be normal for a black tag zf6spd. Go over to zfdoc.com and they have some good stuff to read to get to know our 6spds.
Tom
Overall my 90's 6spd sounds a lot like my old M22 from my C3 only a bit louder. I'd venture a guess to say that what you hear might be normal for a black tag zf6spd. Go over to zfdoc.com and they have some good stuff to read to get to know our 6spds.
Tom
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
Ok well I crawled under his car tonight and it really seems like this noise is coming from the tranny. Its pretty loud at idle, but when you drive it, it goes away. Should he been concerned?? I've done reading about the 6 speeds and the "marbles in a can" sound is normal, but it is pretty loud. Thanks!
Racer
Joined: Aug 2005
Posts: 385
Likes: 0
From: Apopka Florida
It's normal. ZF6's rattle from the factory, nothing is wrong. The dualmass flywheel was supposed to dampen the sound, but it doesn't do the job all that great. When guys switch to single mass flywheels, that rattle gets even louder. If the flywheel has over 100k - 120k it will start is own rattling and should be replaced. Many C4 guys have been down this path before. Welcome to the club.
When the car is in gear the clutch is engaged and the rattle will quiet, sounds right to me.
Normal, Normal, Normal. If it isn't rattling, it isn't a C4.
When the car is in gear the clutch is engaged and the rattle will quiet, sounds right to me.
Normal, Normal, Normal. If it isn't rattling, it isn't a C4.
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
It's normal. ZF6's rattle from the factory, nothing is wrong. The dualmass flywheel was supposed to dampen the sound, but it doesn't do the job all that great. When guys switch to single mass flywheels, that rattle gets even louder. If the flywheel has over 100k - 120k it will start is own rattling and should be replaced. Many C4 guys have been down this path before. Welcome to the club.
When the car is in gear the clutch is engaged and the rattle will quiet, sounds right to me.
Normal, Normal, Normal. If it isn't rattling, it isn't a C4.
When the car is in gear the clutch is engaged and the rattle will quiet, sounds right to me.
Normal, Normal, Normal. If it isn't rattling, it isn't a C4.
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Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
Well he took it to a mechanic that we know and he seems to think it's the clutch release bearing. Does that make sense to anyone? If it where that wouldn't it go away when you press the clutch in?
Last edited by jimmers; May 30, 2007 at 05:54 PM.
Melting Slicks
Joined: Apr 2007
Posts: 2,616
Likes: 111
The noise is normal. I would not have it looked at unless there is a driveabiliy issue. Believe me, I have a new ZF with a single mass, alum. FW....noisy....noisy....I also had (and still have it stored in my garage) a '93 ZF black tag that did the same thing....engage the clutch it goes away...let the clutch out in neutral and it sounds like something is terribly wrong....there should be quite a few threads on this if you search it....I think you will find others echo this....
Last edited by 856SPEED; May 30, 2007 at 07:48 PM.
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
The noise is normal. I would not have it looked at unless there is a driveabiliy issue. Believe me, I have a new ZF with a single mass, alum. FW....noisy....noisy....I also had (and still have it stored in my garage) a '93 ZF black tag that did the same thing....engage the clutch it goes away...let the clutch out in neutral and it sounds like something is terribly wrong....there should be quite a few threads on this if you search it....I think you will find others echo this....
Melting Slicks
Joined: Apr 2007
Posts: 2,616
Likes: 111
Well, there could be a mechanical problem, since I don't know the car. Hopefully there is not. If you heard mine, especially at a low RPM idle, the rattle is very profound, move the engine up the RPM a little at idle (say above 900 RPM), or engage the clutch, the rattle immediately goes away. Under driving conditions, it performs flawlessly. However, I am using a 12.5 lb. alum., SM, FW which is going to produce noise in these trannys. The situation you are referring to may have a problem somewhere. I hope it doesn't. If a factory, DM, steel, FW is in the vehicle you are describing and it is still very noisy, there could be a problem.
Racer
Joined: Aug 2005
Posts: 385
Likes: 0
From: Apopka Florida
Sounds like an excuse to charge him a butt load of money. I had a bad driverside cat that was rattling and I swore my tranny was junk. Make sure to listen with a stethoscope. I started the car and touched the tranny with the stethoscrop and it was smooth, cat was garbage. They were so close in location I swore my tranny was junk, but just the cat. 118k on my ZF6 with the orginal clutch and flywheel and it is just now starting to slip. I would be wary of mechanics when it comes to C4's, its not a T5 its a ZF6, one of a kind.
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
Sounds like an excuse to charge him a butt load of money. I had a bad driverside cat that was rattling and I swore my tranny was junk. Make sure to listen with a stethoscope. I started the car and touched the tranny with the stethoscrop and it was smooth, cat was garbage. They were so close in location I swore my tranny was junk, but just the cat. 118k on my ZF6 with the orginal clutch and flywheel and it is just now starting to slip. I would be wary of mechanics when it comes to C4's, its not a T5 its a ZF6, one of a kind.
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
I think i've got the same issue, what did you to resolve?
All of a sudden I've got this loud rattling noise coming from the transmission. I tried holding on to the pipes/cat/heat shields and the rattle didn't go away... pretty sure it's coming from the transmission on my ZF6.
Could it just be low on fluid?
All of a sudden I've got this loud rattling noise coming from the transmission. I tried holding on to the pipes/cat/heat shields and the rattle didn't go away... pretty sure it's coming from the transmission on my ZF6.
Could it just be low on fluid?
Drifting
Joined: Mar 2004
Posts: 1,443
Likes: 4
From: Grand Rapids Mi
Have driven several 89 ZF-6 cars besides two I own. They have had varying amount of noise especially in first and reverse. Some of early 89 flywheel/transmissions have a fair amount of noise when stopped with clutch disengaged! Some of first owners in 89 had everything replaced under warranty to get less noise, didn't always help. As years went by and transmission kept changing noise gets better, can really notice in 94-96 cars.
Last edited by C-4 Now; Aug 13, 2008 at 07:23 PM.
