Differential Issues - Not Good!
Thread Starter
Heel & Toe
Joined: Feb 2017
Posts: 17
Likes: 2
From: OH
Differential Issues - Not Good!
Had an issue this morning with binding and had to get towed home. When it was being loaded the differential drained onto the flatbed. Found a hole in the body looks like something punched through due to the binding. I will drop the differential and assess it. Have not had to work on these before so any suggestions are appreciated. I have some skill but have never had to work on these. I have a good idea on how to drop it, etc. Now to research costs associated with replacement. I am expecting another case is needed and new some internals. Not a good start to the day...
Last edited by mike1969; Apr 20, 2017 at 11:41 AM.
Le Mans Master
Joined: Mar 2001
Posts: 5,738
Likes: 644
From: Lincoln, CA
It's not hard to remove just time consuming.
I too used a floor jack with straps to hold it in place. I keep a few threads on the cross member bolts to keep it from dropping until I'm ready to lower it.
When mine comes back from tracdogg2 I'm going to use a trans jack to hold it in place.
I too used a floor jack with straps to hold it in place. I keep a few threads on the cross member bolts to keep it from dropping until I'm ready to lower it.
When mine comes back from tracdogg2 I'm going to use a trans jack to hold it in place.
Race Director
Joined: May 2006
Posts: 18,729
Likes: 2,579
I had the same thing happen to me at about 60 mph on the Long Island Expressway. What fun! At the time I had been doing a lot of autocross and HPDE events. The bolts holding the ring gear had loosened and apparently one of the bolt heads sheared and went through the case. It became an excuse to go from a 3:55 to a 3:70.
Last edited by MelWff; Apr 21, 2017 at 11:58 AM.
Melting Slicks
Joined: Jul 2009
Posts: 2,091
Likes: 40
I had the same thing happen to me at about 60 mph on the Long Island Expressway. What fun! At the time I had been doing a lot of autocross and HPDE events. The bolts holding the rear gear had loosened and apparently one of the bolt heads sheared and went through the case. It became an excuse to go from a 3:55 to a 3:70.
your lucky to be alive to tell about that ....wonder people did not just drive right over top of you ......
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Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
Yup the diffy died.
The rear spring is not far behind.
While I'd love to sell you my old 7 leaf 45 lbs lump....the slick replacement is the 360 in. lbs fiberglas spring.
You'll be amazed.
Ps they make upgraded cases now in aluminum for the diffy.
The rear spring is not far behind.
While I'd love to sell you my old 7 leaf 45 lbs lump....the slick replacement is the 360 in. lbs fiberglas spring.
You'll be amazed.
Ps they make upgraded cases now in aluminum for the diffy.
Thread Starter
Heel & Toe
Joined: Feb 2017
Posts: 17
Likes: 2
From: OH
Thanks for the information... I'll be sure to look into those options....👍
Thread Starter
Heel & Toe
Joined: Feb 2017
Posts: 17
Likes: 2
From: OH
Getting parts ready to put the rear end back together. Was wondering if anyone knows what this silvery grease is on the cross member bushings? I checked in the AIM but wasn't able to find anything on it. Thanks
Melting Slicks
Joined: Feb 2017
Posts: 3,232
Likes: 1,232
From: PHX AZ
The 'silvery grease' is MOLYBENDUM DI-SULPHIDE....this is an extreme high pressure grease that 'plates' itself to moving parts.
those of us that have 'funny furrin cars' are very familiar with this, in that All EURO cars have this in the C.V. joints....from the factory.
Pronounced mol-ib-denim.
unkahal
those of us that have 'funny furrin cars' are very familiar with this, in that All EURO cars have this in the C.V. joints....from the factory.
Pronounced mol-ib-denim.
unkahal
Thread Starter
Heel & Toe
Joined: Feb 2017
Posts: 17
Likes: 2
From: OH
I have another question about C3 differentials. I see some differentials state 63-79 but others state 63-77 and 78-79. My question is: I have a '78 differential but the cover is from a '69 - should the '69 cover fit on the '78 differential - what are the differences? If I stick with the '78 what will I need to change? Will I need to change something else out? I am not worried about matching since this is a driver. Thanks everyone. BTW - the issue was that three bolts sheared off the ring gear mount.
Racer
Joined: Oct 2016
Posts: 336
Likes: 69
From: Staten Island New York
I have another question about C3 differentials. I see some differentials state 63-79 but others state 63-77 and 78-79. My question is: I have a '78 differential but the cover is from a '69 - should the '69 cover fit on the '78 differential - what are the differences? If I stick with the '78 what will I need to change? Will I need to change something else out? I am not worried about matching since this is a driver. Thanks everyone. BTW - the issue was that three bolts sheared off the ring gear mount.
somebody did not use RED Lock-Tite
............................. tom n carol
Last edited by MISTERZ06; May 3, 2017 at 09:11 AM.
Thread Starter
Heel & Toe
Joined: Feb 2017
Posts: 17
Likes: 2
From: OH
I hope that is not the case. It was done by a qualified Corvette shop in April '95. Of course it sat from '99-'16 - but I did replace the diff fluid and limited slip fluid last fall (about 500 miles ago).
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
I have another question about C3 differentials. I see some differentials state 63-79 but others state 63-77 and 78-79. My question is: I have a '78 differential but the cover is from a '69 - should the '69 cover fit on the '78 differential - what are the differences? If I stick with the '78 what will I need to change? Will I need to change something else out? I am not worried about matching since this is a driver. Thanks everyone. BTW - the issue was that three bolts sheared off the ring gear mount.
Thread Starter
Heel & Toe
Joined: Feb 2017
Posts: 17
Likes: 2
From: OH
Would I be right to say that I would be able to use the 2 1/2" spring on the '69 Vette then (If I purchased one along with the bracket)? Otherwise I would need to find a pre-78 differential case?
Last edited by mike1969; May 3, 2017 at 12:23 PM.