View Full Version : Rebuilding Rear...

04-23-2003, 09:01 PM
I'm going with a new diff (31 spline) axles (31...duh), gears, the whole nine...my question is what is the deal with the "auburn diff"? how is it different/better than the stock version of the 31 spline...there's like a $100 difference between the two.


04-26-2003, 02:16 AM
From what i have read, the auburns are bit more difficult and costly to rebuild, and the Eaton is a better unit. If you are looking for a cheap route, look for an F250/350 rear end, its essentially an eaton 31 spline unit. if you live in an area with a lot of lifted fords, guys tend to swap these out for lockers and leave them laying around, junk yards are good too... just a sugestion, and it is probably the route i will go when i do mine in the future.

04-26-2003, 10:49 AM
so do f-250 and 350's have 8.8 rears? i always thought they were bigger for some reason.

04-26-2003, 04:18 PM
I talked to someone (can't remember who right off the top of my head) who had the stock 01 S spring and truck S spring tested against each other and were the same rates. That's basically what you'd be after with the truck diff. While the Auburn is a good piece, the Eaton would be a better bet if you plan on spending the money. It's costly to remove the rear, unless you do it yourself, and a rebuilt stock diff with extra plates added is the best way to go, and easy on the wallet. The Eaton is also an easier rebuild vs. the Auburn.


has an excellent write up on the stock diff rebuild. The cost of R&R on an IRS equipped car, with the additional high cost of the Auburn rebuild should be enough deterrent.

04-27-2003, 07:28 PM
i am pretty sure the 250 has an 8.8, dont know about the 350.