The snap ring has come off the splined end of the driver side stub axle inside the differential on my 68 convert. Has anyone ever removed the differential cover plate without taking the differential completely out of the car? I know the answer, but thought maybe someone more clever than me found a way to do it.

 

I've heard that some cars the differential will roll out like a 9 inch. Never seen it or tried.

 

My 69 factory Chassis Service Manual says that's the way it's supposed to be done. For installation it says:
"cut the heads off two 1/2"-13 x 1-1/4" bolts and slot unthreaded end. Install these aligning studs in two below center carrier bolt holes, one on each side. Raise carrier into position aligning studs into cover. Install carrier-to-cover bolts and tighten securely."
I have to do the same job this winter and think I will try it this way.

 

The cover bolts are 7/16-14, there are no 1/2-13 in a vette diff?
Technically you can split the diff from the cover in the car, the old manuals stated the procedure. I would strongly advise you not try it. It is much safer to remove the diff to service it.

 

I can say that I have pulled so many Eaton Differential out of these cars that I would not waste my time trying to do what the 'book' says to save time. Not knowing what Al;L of the written text is telling us to do...and only a small portion that Grant has provided.

Now those who want to do it...I hope all goes well. but I can tell you that if I had your car and another in my shop side by side...chances are I would beat you in getting the cover off and back on even with the differential siting on a floor jack still under the car. No need to cut any bolt head off due to if you already had a bolt needed that already had the head cut off it can be used a the guide pin like GM described..

The trick as I have found is getting the differential cross member down far enough so you can get to the four bolts that hold the cross member to the rear end cover so you can easily access the top two bolts for the rear end cover.

The front differential mount bushing bolt does not need to come out but you darn near take the nut off.

As for the rear leaf spring is need to be uncaged at each trailing arms and unless you want to deal with the added weight of the steel spring being attached to the rear end cover...remove it and then you MUST correctly re-install the bolts and get them torqued WHEN the car is back on the ground so the spring is flat against the rear end cover. IF YOU TRY to tighten up the spring mounting plate bolts to the roughly 60 lbs/ft to 80 lbs/ft of torque when the car is up in the air and it has a steel spring YOU WILL BREAK the rear end cover. Especially if it is a factory rear end cover.

The lower strut rod bracket can be removed and lowered if you want to hassle with it still being in the way.

Hopefully when you get in there your side yoke has not worn down all the way to where the land or groove for the snap ring is no longer there. IF it is...then a new side yoke is needed...obviously. And you might as well get a new fresh pinion shaft also so the new side yoke you buy is not riding against worn rough pinion shaft ....thus tearing it up right off the bat.

Before you start you might want to check the integrity of your clutches in the differential which can be done by using a torque wrench and follow what the service manual states in how to check them,. If my memory serves me correctly an old differential should hold at 40 lbs/ft while a fresh one will at 70 lbs/ft.

Pointless to do ay of this if it is worn out....unless you do not care.

DUB

 

Below is the removal and installation instructions from my 69 Chassis Service Manual. I wonder if the reason for the 1/2-13 bolts as guide pins in so they are loose in the holes and very easy on the threads to remove? No idea unless it's a mistake which is not uncommon.... Arrow in the pic shows the "aligning studs" talked about in the installation instructions.

 

DUB said "The trick as I have found is getting the differential cross member down far enough so you can get to the four bolts that hold the cross member to the rear end cover so you can easily access the top two bolts for the rear end cover."

Thanks, DUB. That was my main concern- how to get to those bolts that hold the cross member to the differential housing. If you don't get them out, you can't remove the cover plate. I am hoping I can get my hands in there to loosen the bolts and then be able to see enough to determine if the end of the axle shaft is good or if it worn so much that the new c clip will come off again. Worst case is that by this point, it will not be that much more work to take the !#$%^&* thing completely out of the car. I shudda boughtta Honda.

 

Well you can do it one way or the other, me I would never split it like that. The diff weighs 100lbs and is full of nasty skunk smelling oil. Even if you suck out most of it there will still be some in there.

Ed's picture with the cover off shows the only holes in the housing, they are all 7/16-14 the 1/2-13 are not going to fit them. I really don't know what the author was thinking? The safest way is to drop the diff and cross member, even the old shade tree method of cutting the floor board over the 4 bolts I like better then splitting it.

Be safe

 

Thanks, Ed T. At which point do I have to break my arm to do it your way? (;

 

I use a six point 5/8" socket to get the four bolts that hold the cross member to the rear end cover off.

I sue my long breaker bar to get them loose than switch to my swivel head 1/2" drive hand ratchet or whatever will work.

Generally I DO NOT do this due to like I wrote I have pulled so many rear differentials it is not a big deal to drop it out from under the car and put it back in.

But it was asked IF it can be done....which it can.

Switching out a rear end cover is ONE THING but messing around with the pinion shaft and side yokes may be better done when you have it on your work bench or jig to be able to work on it easier.

When I pull them I also leave the half shafts attached to the side yokes and the main drive shat attached to the differential and I remove them when I get it on the ground due to it is faster and easier to get to the nuts and bolts to remove them.

I also have the rear of the car up higher and not level so when I pull the drive shaft with the transmission yoke still attached...the transmission does not leak fluid.

The tricky spot is when you go back in when it has the drive shaft attached. Indexing the transmission yoke is not that big of a hassle. You just have to have the differential at the correct height to do so, so you can slide it in without it binding...then the front differential mount bushing can be a but tricky but from what I have found it is still faster than me hassling with putting the driveshaft in after the differential is installed.

DUB