The Stovebolt Site Forums The Shop Area Engine Shop Differential Dissasembly

I need some help. I'm trying to pull the axles on my truck. I've unbolted the diff, but cant remove it. Can someone explain how to get it apart?

mmcdaniel69,

Hope I'm on the same page as you are!! You have to remove the axles before you can remove the differential. You don't have to remove the differential to remove the axles. Instead of trying to explain the operation to remove the axles, I have linked a shop manual description of this operation. Once you see it, all will become clear...I hope.

http://chevy.tocmp.com/1942shop/42csm0401.htm


Stuart

You have to remove the axle shaft spacer screw, which is located on the carrier itself. (it'll be the only screw looking thing on the whole assembly, you might have to turn the carrier to find it, it has a flat head slot). Then remove the rod that goes through the spacer, then the spacer (rectangular box shaped piece in the middle of everything). Things should just fall out after that. Remove the spider gears, then, push the axles inward and remove the c-washer. Then, the axles will pull right out. At this point, it is easier now to unbolt the torque tube from the axle housing. Then you just take it apart according to the manual. I don't know what you are trying to do with yours, but I replaced the 4.11's on mine with 3.55s. I have a 51 GMC 1/2 ton. check out my engine and driveline album on my webshots page for pictures of mine.

need more info,,,on all diff the axel will have to be removed before you can remove the diff as the axel is inserted in the diff to drive the truck,,but need a year and mod as to how to remove the axel...doc

FYI in this latest edition of Vintage Truck there is a review of a book about differentials. Everything you wanted to know but were afraid to ask. Looks interesting.

If it is the 42 GMC 3/4 ton thats in the Gallery you should have 8 bolts that use a 1/2 in wrench on the flange of each axle. When you remove these bolts the axles should slide out. You can then remove the center section of the rear axle if nessesary.

Well, I kinda feel like Homer Simpson right now -DOH!!
I didn't realize that the rear cover came off, there's so much crud on it I just aSSUMEd it was welded on.
The only reason I'm removing the axles is to replace the lug studs. Because of the wheels I've chosen the stock ones are too short and the new ones have to be modified and pressed or tacked in.I couldn't find any longer ones that were direct replacement.
It's the truck in the gallery, but the backing plates are riveted on instead of being bolted.
So I'll put the diff back in place and remove the rear cover. I'll probably be asking for some more advice before I get it back together. Is there anything I need to be careful of while pulling it apart?
By the way automarc Thanks for the link, saved it.

The bolt that holds the cross pin it is notorious for breaking in GM vehicles. Be very carefull taking it loose. It won't break at the threads, it'll break after the threads, leaving the unthreaded part of the pin in the cross shaft. very hard to get out if it does that. Shouldn't be as much of an issue with the old diffs, but I've seen lots of newer ones do that. Sometimes they'll break when they were put in at the factory.

OK, it's apart and that cross pin bolt was hard to get out, I could see where someone had hit it with a punch on one side to tighten it.

Now can it just go back together after I clean it up, or do I need to get some micrometers and check tolerances?

I'm ordering seals and I don't see any excessive wear or pitting it looks to be in pretty good shape.