Need help with clunking noise...
Thread Starter
Intermediate
Joined: Nov 2004
Posts: 41
Likes: 0
From: Western PA
Need help with clunking noise...
While making slow right and left turns, the back of my 78 has a clunking and binding type of noise. Just does it at slow speeds.
Could it be half shafts or what?
It is my first Vette and I am new to this game and any help would be appreciated.
Thanx
Could it be half shafts or what?
It is my first Vette and I am new to this game and any help would be appreciated.
Thanx
Drifting
Joined: Aug 2002
Posts: 1,731
Likes: 22
From: Marietta Ga.
First thing to do is change out rear end lube and be sure to put two bottles of the GM posi lub in, then do figure 8s in a parking lot and see if it goes away.
Here's a past thread
http://forums.corvetteforum.com/show...ght=rear+clunk
do a search in the C3 general section on rear clunk and you will get all the possible causes.
Here's a past thread
http://forums.corvetteforum.com/show...ght=rear+clunk
do a search in the C3 general section on rear clunk and you will get all the possible causes.
Last edited by 72GACRZR; Nov 30, 2004 at 06:42 PM.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Could be the Ujoints, or the posi unit. Also might be the stub axles in the posi, check to see if there is in and out movement. If there is the stub axles are worn and the rear should be rebuilt.
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
The first thing to check, which is the easiest and most likely is the problem, is the differential fluid. It contains special additives for the posi traction clutches built into the diff. The fluid most likely needs changing. You can buy a "rose" gun which is simply a device to suck the old fluid out thru the refill plug on the diff and add new fluid including the special additive. This should cure the problem. One way to check for this is to drive slowly in figure eights in a parking lot. If you hear the noises you referred to this is usually the problem. New fluid with the additives allow the clutches to slip during turns and as the fluid wears it finally gets to the point where the clutches will not slip anymore. Or you can go to a chevy dealer and have them change it for you. Either way it should solve your problem. Good luck with your vette! 
Thread Starter
Intermediate
Joined: Nov 2004
Posts: 41
Likes: 0
From: Western PA
I have had it for about 6 weeks and have only had it out about 5 or 6 times. First few times out I did not notice this.
It has just been the last 2 or 3 times that it has started doing this.
Thanx
It has just been the last 2 or 3 times that it has started doing this.
Thanx
