Differential Problem?
Thread Starter
Intermediate
Joined: Nov 2012
Posts: 45
Likes: 0
Differential Problem?
Here is my problem. I have a 71 vette and I hear a thumping sound coming from the back of the car. Now the only time i hear it is when the car has been driving for a while say 10 miles or so. just around town i don't hear anything. The noise only appears when i make a right turn after a stop and sometime when i make a left turn after i stop.
it's only one or two thumps then gone. Now i recently replaced both trailing arm assembly with rotors and brakes. New strut rods and new u joints. Just about everything is new in the back of the car. i'm lost and it's driving me crazy. somebody please help.
Jim
it's only one or two thumps then gone. Now i recently replaced both trailing arm assembly with rotors and brakes. New strut rods and new u joints. Just about everything is new in the back of the car. i'm lost and it's driving me crazy. somebody please help.
Jim
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
Notice also that there is no 'drain' plug for the gear oil.
You are either going to have to remove the cover to get the old oil out, or use tube in the 'fill' plug, get it to the bottom of the case, and vaccum it out.
Getting the fill plug out if the least of it.
Now... if your side yokes have end play, and need to be replaced, you have to get the diff down... again the whole rear susp needs to pretty much come out.
Thread Starter
Intermediate
Joined: Nov 2012
Posts: 45
Likes: 0
I can't get the plug out so i'm going to drop it off at my mechanics shop tomorrow and let him deal with it on the lift. I believe I had the bearings and u joints replaced at the same time. we shall see tomorrow.
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Melting Slicks
Joined: Apr 2001
Posts: 2,030
Likes: 363
From: Lubbock Texas
DC
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
You might have a warped rotor? After the brakes get hot it may be more pronounced....
My rear creeks a little on tight parking lot turns but not loud. It's just the posi clutches slipping.
My rear creeks a little on tight parking lot turns but not loud. It's just the posi clutches slipping.
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
He could also install a drain plug. Pretty easy to drill a hole and tap it for a plug. There are old threads on the site that will show how to do this. It took longer to get my '73 on and off the ramps than it did to drill the hole, tap it, and replace the fluid. Do make sure you can get the fill plug loose before starting. Be a shame to drill the hole and then find out you couldn't remove the fill plug.
DC
DC
Burning Brakes
Joined: Jul 2008
Posts: 1,004
Likes: 27
From: South Louisiana offshore, Gulf of Mexico
Drain plug- heat up the case around plug w/ a propane torch.
Use a large syringe w/ a piece of flexible tubing and suck the oil out.
Thats what I did anyway
On the bumping noise, my 68 differential bushing mount was loose and the diff would thump once on acceleration, and once on deceleration due to torque.
Use a large syringe w/ a piece of flexible tubing and suck the oil out.
Thats what I did anyway
On the bumping noise, my 68 differential bushing mount was loose and the diff would thump once on acceleration, and once on deceleration due to torque.
Thread Starter
Intermediate
Joined: Nov 2012
Posts: 45
Likes: 0
thanks for all your help. i spoke with my mechanic this morning and he has a vacuum to do this. he said i can bring the car over Monday and we can put it on the lift and change the fluids. i hope this will fix the noise. wish me luck.
thanks again for your help
thanks again for your help
Burning Brakes
Joined: Sep 2006
Posts: 851
Likes: 10
From: Palm City, FL
He could also install a drain plug. Pretty easy to drill a hole and tap it for a plug. There are old threads on the site that will show how to do this. It took longer to get my '73 on and off the ramps than it did to drill the hole, tap it, and replace the fluid. Do make sure you can get the fill plug loose before starting. Be a shame to drill the hole and then find out you couldn't remove the fill plug.
DC
DC
If it was me, I would do it, but I would do it with the case down and cover off, to make sure I get all the metal out.
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
If your going to make a drain hole, I wouldn't do it this way.... there is no way you made the hole and tapped it, without getting some metal into the case.
If it was me, I would do it, but I would do it with the case down and cover off, to make sure I get all the metal out.
If it was me, I would do it, but I would do it with the case down and cover off, to make sure I get all the metal out.
The sucking out looks like a better option.Anyway, I'm going to bet the yokes have play and then it's better to lower the diff. I've never done this with the body on the car, but I can imagine the fuss doing it. I just had to replace a bolt on the front bushing of my trailing arm and that alone was a mayor PIA. I was Lucky my son with his small hand was able to push the bolt in the hole...
If you take the diff out, get it tuned. I did mine and no shattering, hammering anymore. Fine lsd operation.
Melting Slicks
Joined: Apr 2001
Posts: 2,030
Likes: 363
From: Lubbock Texas
If your going to make a drain hole, I wouldn't do it this way.... there is no way you made the hole and tapped it, without getting some metal into the case.
If it was me, I would do it, but I would do it with the case down and cover off, to make sure I get all the metal out.
If it was me, I would do it, but I would do it with the case down and cover off, to make sure I get all the metal out.
DC
Melting Slicks
Joined: Apr 2001
Posts: 2,030
Likes: 363
From: Lubbock Texas
DC