ZF-6 Owners - HELP!!
Thread Starter
Racer
Joined: Apr 2005
Posts: 484
Likes: 5
From: Madison Wisconsin
ZF-6 Owners - HELP!!
I have a 93' with 46K miles. Earlier this summer I replaced the clutch, master and slave cylinders because the clutch was very stiff and the car didn't shift well. The shifting and clutch force is much improved. However I occasionally get a groaning noise coming from the bell housing when I depress and release the clutch pedal. It's usually most noticeable on the last half of the pedal travel to the floor (both when depressed and released) and when I've driven the car for a few miles. The strange thing is it comes and goes. Sometime the pedal is as smooth glass and other times I feel as if something is rubbing and I heard this groaning noise. I know it's not the pedal itself. It appears it is coming from inside the bellhousing. Any idea?? I kept my old release bearing and it really doesn't show much wear. There are some very small marks where the fork contacts the flange and where the bearing rides on the guide tube. However from a novice perspective, it certainly didn't look like a lot of wear. When I installed the Valeo clutch I followed Perfection Clutch's instructions to the letter and used a good wheel bearing grease on all the wear points? I could certainly use anyone experience on this one.
Thanks all,
Jim
Thanks all,
Jim
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Sounds exactly like your throwout bearing is going out or defective. It makes noise when you load and unload it, the bearing races are probably chewed up.
Burning Brakes
Joined: Oct 2004
Posts: 1,019
Likes: 1
From: Weymouth Dorset
Originally Posted by CentralCoaster
Sounds exactly like your throwout bearing is going out or defective. It makes noise when you load and unload it, the bearing races are probably chewed up.
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Thread Starter
Racer
Joined: Apr 2005
Posts: 484
Likes: 5
From: Madison Wisconsin
Interesting. Thanks for the quick response. Let me throw another twist. I hear the noise regardless of when the engine is running or not. Do you still think it is the throw out bearing?
Thanks again,
Jim
Thanks again,
Jim
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Thread Starter
Racer
Joined: Apr 2005
Posts: 484
Likes: 5
From: Madison Wisconsin
Thanks for the GM clutch fluid suggestion. Unfortunately I've already tried that as well. It's more of a groan than a creak. It seems to be almost heat related in the sense that I notice most after I drive the car. Overnight the groan goes away. I also feel as if something is rubbing as I push down and release the pedal. Although it is really only the last half of the throw before it bottoms out near the floor. If I pull out the slave I can easily pivot the throw out fork on the pivot ball. Consequently I think it is either the guide tube or the throw out fork where it contacts the throw out bearing. However when I installed the clutch I really didn't see much wear on either. I welcome any thoughts.
Jim
Jim
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Might it be the clutch fork pivot ball backing-out of the bell-housing/locking nut, changing the pivot angle of the fork's contact with the release bearing (aka throw-out bearing)?
Has the engagement/dis-engagement point on the clutch/pedal changed/gotten higher (this was the symptom on ours for the loosening pivot-ball)?
hope this helps
Has the engagement/dis-engagement point on the clutch/pedal changed/gotten higher (this was the symptom on ours for the loosening pivot-ball)?
hope this helps
Thread Starter
Racer
Joined: Apr 2005
Posts: 484
Likes: 5
From: Madison Wisconsin
Thanks for the tip. It's possible, however the clutch engagement hasn't really changed since I installed the new pressure plate and I torqued the ball and locking screw to the specs when I installed them. The weird thing is the fact that it comes and goes and is only noticable at the last three inches of pedal travel in both directions. It almost seems to be heat related. I'm stumped!! Is it possible to pull the throw out fork without removing the bellhousing? I'm guessing no, but I thought I'd ask.
Race Director
Joined: Feb 2003
Posts: 11,671
Likes: 20
From: Lake Wylie SC
I thought I'd throw this in there for you. Here is a rule that most follow, when replacing the clutch always replace the pilot and release bearings. I carry it one step farther, I replace the fork and ball if I see any wear at all. From what I've read on this thread if it were me, I'd pull it apart and replace the release bearing, fork and ball. It's hard to feel or visually inspect a release bearing. The wear on a fork is critical with this clutch set up.
Thread Starter
Racer
Joined: Apr 2005
Posts: 484
Likes: 5
From: Madison Wisconsin
Thanks Strick, I appreciate the additional thoughts. A new throw out bearing came with the pressure plate. However I suspect my problem might be wear on the fork. I replaced the original pressure plate not because it was slipping, but rather because the clutch pedal was very difficult to depress and the car was difficult to shift. Two Corvette shops told me the pressure plate was probably bad. It's possible the fork wore excessively under the increased load and I just didn't notice the wear when I examined the parts. I think a new fork and pivot ball is probably in my future. Do you know if it's possible to pull the fork without pulling the bell housing??
Jim
Jim
Race Director
Joined: Feb 2003
Posts: 11,671
Likes: 20
From: Lake Wylie SC
Originally Posted by jimkari
Thanks Strick, I appreciate the additional thoughts. A new throw out bearing came with the pressure plate. However I suspect my problem might be wear on the fork. I replaced the original pressure plate not because it was slipping, but rather because the clutch pedal was very difficult to depress and the car was difficult to shift. Two Corvette shops told me the pressure plate was probably bad. It's possible the fork wore excessively under the increased load and I just didn't notice the wear when I examined the parts. I think a new fork and pivot ball is probably in my future. Do you know if it's possible to pull the fork without pulling the bell housing??
Jim
Jim
Thread Starter
Racer
Joined: Apr 2005
Posts: 484
Likes: 5
From: Madison Wisconsin
Thanks Strick. I probably tear into it in the next few weeks. f yuo don't mind me asking, what type of grease do you place on the throw out fork, pivot ball and guide tube. I used a wheel bearnig grease.
Jim
Jim
