Help, changing rear diff seals
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
What year of rear diff are you referring to?
Maybe this will help to answer the question, although let me first preface this by admitting to not being an expert:
1. In order to get the old seal off and a new seal on the half shafts must be removed from the axle yoke end at the very least.
2. The stub axles need to be removed to install new seals.
3. The stub axles can't be removed unless the rear cover is removed (this is debatable because maybe the axle clips aren't there).
4. The rear cover can't be removed unless the leaf spring is removed.
5. Exhaust is optional depending on what version/year.
6. If you have gone this far what is a few more bolts, depending on year of course.
I want to answer No it cannot, but there will be a few brave souls who'll say that it can be done without removing the diff unit.
Maybe this will help to answer the question, although let me first preface this by admitting to not being an expert:
1. In order to get the old seal off and a new seal on the half shafts must be removed from the axle yoke end at the very least.
2. The stub axles need to be removed to install new seals.
3. The stub axles can't be removed unless the rear cover is removed (this is debatable because maybe the axle clips aren't there).
4. The rear cover can't be removed unless the leaf spring is removed.
5. Exhaust is optional depending on what version/year.
6. If you have gone this far what is a few more bolts, depending on year of course.
I want to answer No it cannot, but there will be a few brave souls who'll say that it can be done without removing the diff unit.
Melting Slicks
Joined: Apr 2008
Posts: 2,625
Likes: 242
From: Russell Ontario
St. Jude Donor '09
I have done mine "both outputs" and I just pulled the diff , it was easier, and I pressure washed the whole unit! It took about an hour to pull it out,I have an 80 and the whole thing only weighs about 50lbs , if the side yokes don't come out easely check the end were the clip was, the end is probably "burred" You can tap them gently or file them! keep us updated , I have pics if you want them, Ron
Last edited by RonR80; Feb 4, 2010 at 08:37 AM. Reason: spelling
Racer
Joined: Jan 2007
Posts: 314
Likes: 0
From: Pittsfield, Ohio
"While I'm at it" 
Thats what happend to me anyways. A two hour, two seal replacement job morphed into a new gear ratio, HD carbon carrier clutch pack kit, u joints, shocks, installing the rear 1/2 of a VBP big daddy kit, pulling the tank, wiring, painting, on and on..
(hey it was winter anyways)
Thats what happend to me anyways. A two hour, two seal replacement job morphed into a new gear ratio, HD carbon carrier clutch pack kit, u joints, shocks, installing the rear 1/2 of a VBP big daddy kit, pulling the tank, wiring, painting, on and on..
(hey it was winter anyways)
Last edited by 2armor; Feb 4, 2010 at 09:42 AM.
Thread Starter
Racer
Joined: Dec 2008
Posts: 255
Likes: 4
Thanks guys, sorry the car is a 1970. I removed the leaf spring (rebuilding the spring and new end bushings) and the exhaust and spare tire tub. My question is, the rear is bolted at the top with 4 bolts to the cross member. Do you have to remove the crossmember or is there a way I cannot see to just remove the bolts. If you have to remove the cross member are there nuts on the bolts which go through the bushings or can they just be turned out (it seems preety tough to get to the top if there are nuts there). Thanks all for your help
Thread Starter
Racer
Joined: Dec 2008
Posts: 255
Likes: 4
Another stupid question, can you unbolt and remove the cover while still bolted to the crossmember and just pull the diff out from the front leaving cover bolted to crossmember after removing driveshaft and front diff mount? I hear removing the crossmember is a b*tch.
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Thread Starter
Racer
Joined: Dec 2008
Posts: 255
Likes: 4
rear seals
What does the reinforcement plate reinforce? So I guess the crossmember has to come down? I will order rubber bushings. I am sure they are a real party to replace after 40 years.
A penguin brings his leaky car into a repair facility. While its being repaired he gets himself a vanilla ice cream cone. When he gets back there is another penguin waiting for his car. The 2nd penguin says to the first penguin, did you blow a seal? He answered, No it's just a little ice cream.
A penguin brings his leaky car into a repair facility. While its being repaired he gets himself a vanilla ice cream cone. When he gets back there is another penguin waiting for his car. The 2nd penguin says to the first penguin, did you blow a seal? He answered, No it's just a little ice cream.
Racer
Joined: Nov 2005
Posts: 409
Likes: 5
From: Orange County CA
I removed my differential twice without dropping the crossmember.. My crossmember would not come out, at least not without any force that I felt comfortable putting on it..I had to remove it again after I realized one of the clips that holds the axle stub fell off. I didnt realize it until after the spring and all connecting parts were back in..
I used a 5/8 deep socket on a long flex head ratchet through the access holes on top of the crossmember.. Not too difficult..I used new bolts and chased the threads in the rear end before reinstalling it to make it easier to start the bolts.
Make sure to use some kind of jack under the diff when you remove it.. it is pretty heavy. I used a transmission jack from Harbor Freight.. worked like a charm..
I would replace the pinion seal and check the bearings while you have it out..
I used a 5/8 deep socket on a long flex head ratchet through the access holes on top of the crossmember.. Not too difficult..I used new bolts and chased the threads in the rear end before reinstalling it to make it easier to start the bolts.
Make sure to use some kind of jack under the diff when you remove it.. it is pretty heavy. I used a transmission jack from Harbor Freight.. worked like a charm..
I would replace the pinion seal and check the bearings while you have it out..
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
Rick B.
Thread Starter
Racer
Joined: Dec 2008
Posts: 255
Likes: 4
Thanks for all your help, I have, in the end removed the whole rear from the car. I got the cross member out with lots of lubricant and a very long pry bar. I surpported the diff with a jack but was lucky to have friend over helping me. I am also lucky to have a four post lift so I didnt have to do it laying on my back. It does appear that one of the yokes is a little sloppy so I will replace the bearings and seals. Now that I have the diff sitting on my work bench I hope these procedures wont be too difficult. I will also change strut rod bushings and replace leaf spring separators and end rubbers. Seems like I will have time in since we ar expecting a snow storm this weekend. What is the deal with replaceing the cross member bushings? It looks like they have some tabs that need to be lifted to be removed. Thanks again for all your help.
Racer
Joined: Nov 2006
Posts: 264
Likes: 0
From: McLouth Kansas
When you install the crossmember back in the car,,,grease up the bushings with some water proof grease,,I used a grease from a motorcycle shop called "Belray" it comes in a little tub. There for if you need to remove the crossmember sometime in the future it will come down much easier.
And add a drain hole in the bottom of the housing,,,tap it out for a 1/8 pipe plug, making a oil change much easier.
And add a drain hole in the bottom of the housing,,,tap it out for a 1/8 pipe plug, making a oil change much easier.
Racer
Joined: Jan 2007
Posts: 314
Likes: 0
From: Pittsfield, Ohio
When you install the crossmember back in the car,,,grease up the bushings with some water proof grease,,I used a grease from a motorcycle shop called "Belray" it comes in a little tub. There for if you need to remove the crossmember sometime in the future it will come down much easier.
And add a drain hole in the bottom of the housing,,,tap it out for a 1/8 pipe plug, making a oil change much easier.
And add a drain hole in the bottom of the housing,,,tap it out for a 1/8 pipe plug, making a oil change much easier.
I used the exact same grease too! U must be a fellow offroad enthusist. That silver aluminum round disc is the reinforcement I mentioned earlier. I ordered mine from VB&P but its concept can easily be made from 1/4" steel or aluminum if you have the material. I couldn't locate the part on vbp site to list here as their site is not real user friendly IMO like some sites. I guess if you know the proper name a search would be successful though.
The first time I took my upper diff support crossbar off, I had to use a breaker bar to separte the crossmember rubber socket from the frame pin .. I though a was going to bust a nut.
Last edited by 2armor; Feb 5, 2010 at 11:51 AM.
Thread Starter
Racer
Joined: Dec 2008
Posts: 255
Likes: 4
What is the purpose of the reinforcement plate under the x-member? Is it a safety thing? I have been checking the diff and found that one of the yokes has some play in it. would new bearings take care of that or could it be something more complicated? How tough are the bearings to put in once the rear cover is off and the diff is on the work bench?
Racer
Joined: Jan 2007
Posts: 314
Likes: 0
From: Pittsfield, Ohio
The disc is the same size radius wise as that crimped in rubber damper on the crossmember. It gets mounted on the bottom side of the crossmember. Mine rubber insert frame had like little tabs bent over holding it in all the way around the insert. The crossmember retaining bolt (I used Grade 8) goes through the disk to enforce those tabs from bending/loosening under torque.
I hope I described it correctly. Too bad I dont have a picture of it on the car for ya..
I hope I described it correctly. Too bad I dont have a picture of it on the car for ya..