Rebuilding the rear axle

Scoutdog72 · 11-15-2003

1972 GT/Since I had to sandblast the rear axle (and add brackets for the stabilizer rod) it seemed wise to do a rebuild. I have the axles out but was wondering if there is a good method for removing the axle shaft bearings and seals. I also noticed a hole on the top right side of the axle carrier (about midway between the differential and the brake support plate. What is its purpose? And with out the special spline wrench how can the pinion preload nut be removed? I have the sinking feeling I'm in over my head.

Thanks for the help/Mike

namba209 · 11-15-2003

Mike, unless you are really familiar with overhauling rear-ends, I personally would leave it to the pros. There are a lot of preloads that have to be set right with shims, if it's not right the rear-end won't be happy. Also they would have the tools and expertise to remove the axle bearings. I had my ZF posi done by the local pros here inSANe DIEGO and the total cost to remove the old rear-end gear set and install the NOS ZF was under $250. I had an agreement with Gil at OGTS to send them any parts that needed to be replaced and he supplied them with all they needed. He has everything needed to overhaul the rear-end except for one part, and I can't rmemeber which one it was. The hole you are referring to is a breather port, there should be a floating plastic cap covering it. Just my $.02.

Ron

garrymc · 11-15-2003

I have the axles out but was wondering if there is a good method for removing the axle shaft bearings and seals.

I think the only way to remove the bearings is to cut them off with some kind of grinder...I might be wrong. I just did rear bearings (for the 2nd time) on my 9 inch rear Bronco and they are press on, cut off.

PROPEL · 11-15-2003

He (OGTS) has everything needed to overhaul the rear-end except for one part...

I believe that would be the pinion nut, as I remember.

kwilford · 11-15-2003

I rebuilt a GT differential once, about 20 years ago, when Myrna's GT ate a spider gear and spit it right through the rear cover!!! I bought a used internal gear set from a friend and replaced it in the old housing with new bearings and seals, and shimmed it using the mix of shims from both rear ends. I can't remember why I didn't just use the other diff, but there must have been something wrong with it.

Ron is right, the shims and pre-loads are a bit tricky, but if you follow the FSM, you should do OK. But if you don't need to rebuild the gear set, just do the outer bearings (which have integral seals, after mid 1970). And yes, you have to split the retaining rings to remove the bearings, and press on new rings (from OGTS) after you slide the new bearings on. Here's a picture from the FSM:

garrymc · 11-15-2003

and you will need a shop press to put on the new bearings...

Garry

Scoutdog72 · 11-16-2003

Thanks for the input! The diassembly is required due to the sanblasting. Plus everything is original and I've gone this far I might as well do it right. I figure with the axles out and going through all the work it would be a mistake not to have the pinion seals replaced. I can cut off the bearing seals that are press fit on with my cut off wheel and then use a sharp chisel. I'll that a search of the local shops that work with transmissions and diffentials of this vintage. So I drop a few $$$ - couple of less toys for my son at Christmas. Mike

Scoutdog72 · 11-24-2003

I tracked down a shop that can get my differential back together and do a lot better job than I can. It's only money.

I have purchased the brackets from Opel GT so I can add the stabilizer rod. They only provided one measurement which is the distance c/l between the two brackets (left to right). No problem there but what about positioning them up and down? How critical is this? Opel GT provided a drawing but the best I can do is eyeball with the spring seat.

I don't have a stabilzer rod at this time and the entire body is stripped of everything (except for the rust

). My plan was to get these welded, have the shop put the diffential back together, and then work on the brakes in the basement over the course of the winter. Where it is a lot warmer. Any help or thoughts are appreciated.

Mike

nobody · 11-24-2003

I just put that same bar on mine. I asked Gil the same question, and was told that I should put the bar and body mounts on first.What made me call was that my bar was narrower than the dimensions in the instructions. anyway then you center it up and then you can center your brackets to the axle. This way no matter where your car is sitting it won't try to go through the body or bind on the diff. Just a note that I realized while typing. My car is lowered so if I were to go back to a stock height. The geometry would change and the bar would be out of place. You could make new plates for it I guess. Sorry but after doing it there really doesn't seem to be 1 definite angle.

Scoutdog72 · 11-25-2003

Thanks for the info. After thinking about it I can still prep the rear axle and do all the work. At the right time I can always scarp away the paint and weld them into position.

11-15-2003	#1 (permalink)
Scoutdog72 Opeler Join Date: Jan 2003 Location: Massachusetts Posts: 31	Unanswered: Rebuilding the rear axle 1972 GT/Since I had to sandblast the rear axle (and add brackets for the stabilizer rod) it seemed wise to do a rebuild. I have the axles out but was wondering if there is a good method for removing the axle shaft bearings and seals. I also noticed a hole on the top right side of the axle carrier (about midway between the differential and the brake support plate. What is its purpose? And with out the special spline wrench how can the pinion preload nut be removed? I have the sinking feeling I'm in over my head. Thanks for the help/Mike

11-16-2003	#7 (permalink)
Scoutdog72 Opeler Join Date: Jan 2003 Location: Massachusetts Posts: 31	all good replies Thanks for the input! The diassembly is required due to the sanblasting. Plus everything is original and I've gone this far I might as well do it right. I figure with the axles out and going through all the work it would be a mistake not to have the pinion seals replaced. I can cut off the bearing seals that are press fit on with my cut off wheel and then use a sharp chisel. I'll that a search of the local shops that work with transmissions and diffentials of this vintage. So I drop a few $$$ - couple of less toys for my son at Christmas. Mike

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11-15-2003	#2 (permalink)
namba209 6,000 Post Club Join Date: Aug 2002 Location: Imperial Beach, CA South of San Diego Posts: 6,054 Provided Answers: 6	Mike, unless you are really familiar with overhauling rear-ends, I personally would leave it to the pros. There are a lot of preloads that have to be set right with shims, if it's not right the rear-end won't be happy. Also they would have the tools and expertise to remove the axle bearings. I had my ZF posi done by the local pros here inSANe DIEGO and the total cost to remove the old rear-end gear set and install the NOS ZF was under $250. I had an agreement with Gil at OGTS to send them any parts that needed to be replaced and he supplied them with all they needed. He has everything needed to overhaul the rear-end except for one part, and I can't rmemeber which one it was. The hole you are referring to is a breather port, there should be a floating plastic cap covering it. Just my $.02. Ron

11-15-2003	#6 (permalink)
garrymc Member Join Date: Feb 2003 Location: Phoenix Posts: 235	and you will need a shop press to put on the new bearings... Garry

11-24-2003	#8 (permalink)
Scoutdog72 Opeler Join Date: Jan 2003 Location: Massachusetts Posts: 31	I tracked down a shop that can get my differential back together and do a lot better job than I can. It's only money. I have purchased the brackets from Opel GT so I can add the stabilizer rod. They only provided one measurement which is the distance c/l between the two brackets (left to right). No problem there but what about positioning them up and down? How critical is this? Opel GT provided a drawing but the best I can do is eyeball with the spring seat. I don't have a stabilzer rod at this time and the entire body is stripped of everything (except for the rust ). My plan was to get these welded, have the shop put the diffential back together, and then work on the brakes in the basement over the course of the winter. Where it is a lot warmer. Any help or thoughts are appreciated. Mike

11-24-2003	#9 (permalink)
nobody No Access Join Date: Nov 2003 Location: in transit Posts: 3,873 Provided Answers: 1	I just put that same bar on mine. I asked Gil the same question, and was told that I should put the bar and body mounts on first.What made me call was that my bar was narrower than the dimensions in the instructions. anyway then you center it up and then you can center your brackets to the axle. This way no matter where your car is sitting it won't try to go through the body or bind on the diff. Just a note that I realized while typing. My car is lowered so if I were to go back to a stock height. The geometry would change and the bar would be out of place. You could make new plates for it I guess. Sorry but after doing it there really doesn't seem to be 1 definite angle.

11-25-2003	#10 (permalink)
Scoutdog72 Opeler Join Date: Jan 2003 Location: Massachusetts Posts: 31	Thanks for the info. After thinking about it I can still prep the rear axle and do all the work. At the right time I can always scarp away the paint and weld them into position.

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