A noise from the rear end
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 26
Likes: 3
From: Aliso Viejo CA
A noise from the rear end
Well, my car ('72, 4-speed) has developed a new noise coming from around the differential. I've searched the forum and haven't found quite the same thing, so I thought I'd ask.
When driving, it sounds like the car is dragging a tin can. Only happens when the car is moving (not at idle), isn't affected by clutch position, gear, or engine speed. It's not loud enough to hear from inside the car, except when I pass something that reflects the sound, like another car or a wall.
I got under the car and had my wife turn the rear wheels, and I could hear the noise. At hand-turned speed, it sounds like an intermittent metallic scraping noise or "ring". The noise is coming the area of the U-joint at the front of the differential. It doesn't sound at all to me like there is any noise from the internal workings of the diff, which I hope is a good sign...
I've never heard a bad U-joint, but my noise doesn't match the description I've heard (like a clunk). I don't see any play in the U-joint, either. I'm suspicious of the cover between the U-joint and differential housing, which turns with the driveshaft. Could it be scraping and causing this noise? Can it be lubricated/resealed/adjusted?
Any ideas? Think it's worth replacing the U-joint or differential oil, just to check?
When driving, it sounds like the car is dragging a tin can. Only happens when the car is moving (not at idle), isn't affected by clutch position, gear, or engine speed. It's not loud enough to hear from inside the car, except when I pass something that reflects the sound, like another car or a wall.
I got under the car and had my wife turn the rear wheels, and I could hear the noise. At hand-turned speed, it sounds like an intermittent metallic scraping noise or "ring". The noise is coming the area of the U-joint at the front of the differential. It doesn't sound at all to me like there is any noise from the internal workings of the diff, which I hope is a good sign...
I've never heard a bad U-joint, but my noise doesn't match the description I've heard (like a clunk). I don't see any play in the U-joint, either. I'm suspicious of the cover between the U-joint and differential housing, which turns with the driveshaft. Could it be scraping and causing this noise? Can it be lubricated/resealed/adjusted?
Any ideas? Think it's worth replacing the U-joint or differential oil, just to check?
Drifting
Joined: Aug 2009
Posts: 1,635
Likes: 8
From: Enid Oklahoma
It could be the pinion bearing..... however they usually whine, but if the bearing os actually going it can sound metallic. It never hurts to change the fluid and see if it gets worse or better. I know you will get ideas and someone may give you a better one, good luck!
Melting Slicks
Joined: Mar 2009
Posts: 3,126
Likes: 15
Remove the driveshaft and ck. u-joints. Then turn pinion yolk with driveshaft removed. Do you see any rust colored dust around the driveshaft u-joints? If you do, then they are bad. It would not be an option to try to do the pinion bearing with diff. in the car. mike...
Last edited by mds3013; Aug 20, 2010 at 06:32 PM.
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 26
Likes: 3
From: Aliso Viejo CA
I'll wrap this up for anyone searching in the future...
The problem turned out to be that the dust deflector on the front of the differential had come loose, and was rattling around. It's supposed to be fixed to the front yoke, so I just stuck it in lace with JB Weld, and the noise went away.
Someone else had the same problem in this post: http://forums.corvetteforum.com/c3-g...on-flange.html
The problem turned out to be that the dust deflector on the front of the differential had come loose, and was rattling around. It's supposed to be fixed to the front yoke, so I just stuck it in lace with JB Weld, and the noise went away.
Someone else had the same problem in this post: http://forums.corvetteforum.com/c3-g...on-flange.html
