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Differential carrier holding fixture question

Posted: Tue Sep 17, 2013 8:49 pm
by Rich Jordan
I've got very limited space in my garage but clearing what I can to get back to work on the Challenger. I have a decent rolling engine stand and a small but strong wallmount workbench; I've had 500 pounds sitting on it and there's no indication of strain.

I'm going to be tearing down a couple of 8-3/4" Mopar differential cores and eventually rebuilding two (one 2.76 highway gear, one probably 3.91 for fun); like the Ford 9", these Chrysler differentials can be removed from the front of the axle housing without messing with the pinion shaft, so doing a swap is messy but not too hard.

OTC has this fixture which has a great reputation but is pricey; there are cheaper alternatives (like this on ebay) which may be just as good for my purposes (I don't do this for a living). These mount to the bench; I have an 8"x8" 1/4" thick steel plate I could use on the underside for reinforcement if that is needed, and I can drill the holes as needed

But OTC also has this, which uses their engine stand as a base. I might need to drill different holes in my stand's faceplate to match, but I can make it work. The engine stand can't be as stable as the workbench but I can move it wherever there's room (an important but probably not vital feature); I can always pile some weight on the legs to help keep it from moving too much but it will never be as stable as the bench.

I'd like to save the money; replacement North American bearings and seals (and new gears if needed) have gotten very pricey and I won't be using chinese parts. I'd also like to have the portability of using the engine stand version. Anyone here done differential/carrier work before and care to share an opinion on the usability trade-off between bench mount and the engine stand version?

Re: Differential carrier holding fixture question

Posted: Tue Sep 17, 2013 10:09 pm
by TheIrishman
The 3rd members aren't that heavy. You could knock something together out of scrap angle iron for a few bucks if you have a welder handy. That's what I did when I had to rebuild diffs in buses. 2x2x1/4 angle is more than strong enough.

Re: Differential carrier holding fixture question

Posted: Tue Sep 17, 2013 11:31 pm
by Rich Jordan
No welder available, and my fall semester 'fundamentals' class at the community college was canceled, so no hobby access either until the next semester

The pigs aren't that light either; I want something strong enough, especially for doing the rather high torque pinion nut tightening.

Re: Differential carrier holding fixture question

Posted: Wed Sep 18, 2013 2:31 am
by blackeagle603
especially for doing the rather high torque pinion nut tightening.
That's what the actual rearend is for 8-) -- should be able to use it for a fixture when you're torquing that pinion nut. We'd just take them to "Harvey" a sympathetic older shop owner who'd spin them on tight w/ his 3/4" impact. Not that it was calibrated... Never had a problem though. Long time ago circa ~78-80, did a lot of swaps just like you describe, for the reasons you describe. Poor man's door slammer bracket racing