Hey folks, I've got a 1990 F250 here that I am planning on doing a front axle swap on (possibly rear as well).
I'm having trouble identifying the rear axle on my truck (would like to know if it is compatible with the front axle so I can swap the front first and run it for a bit, then swap the rear at a later date..)

It has no exterior tag on the diff.
The top inner surface of the diff has stamped
8
E7TW-AA
4157
On the inner drivers side is stamped < 5TAA(triangle)(triangle)DW28 >
And on the inner passenger side is stamped < 5TAA(triangle)(triangle)DW17)

I cannot run the numbers on the door pillar as the P.O. swapped the axle and engine into the truck. Anyone able to tell me what I got?

 

Post up some Pictures, Ford casting numbers aren't much help.

 

Okay, here are a couple photos of the axle I am trying to identify.

 

Also, I would like to identify the donor axles as well, If anyone has any clue what these might be would love to know! So far I know that the front axle is a Dana 60 kingpin, and both of these axles are sitting underneath a 1986 custom F350.
(Front axle isn't the easiest to see right now, if more angles are needed can get better ones upon request)

 

Both rear axles are Sterling 10.25" axles.

 

And get there she shall! I restore vehicles for a living, so I didn't mind starting with something ugly, (that may have gone to the wrecker in other hands) and nursing it down the long road to beautification. First, make her tough, then the cosmetic stuff. This is why I'm starting in the axles department.

Was hoping to find out if the Custom 350 had a posi or limited slip in it as well, as mine most certainly does not! Any input on how to go about figuring that out? Is a parts truck and will not be running, ever. Would like to find out BEFORE I install it in my daily, if possible.

 

Get both rear wheels off the ground turn the wheels if they turn the same direction with some effort it is a limited slip. If they turn opposite it is an open rear.

 

Find the axle code on the drivers door pillar and post it up, that will decode to give you the gear ratio and diff type. The only diff options in these trucks are open and limited slip.

 

There is no "1 ton axle" when it comes to the rear. The 3/4-ton and 1-ton pickups have the same axle. IIRC, they sit on different sized blocks, depending on whether the front is 3/4-ton or 1-ton. So if the gear ratio is the same, why would you want to swap the rear? Unless you currently have an open diff and the donor is an LS, perhaps. Even then, it's some work for not a lot of gain; the performance of the Sterling LS isn't exactly sterling....

 

The main reason that I would have been swapping the rear as well would have been if my rear end had different gears than the Dana 60 front axle that I am dropping in. Since it appears to have the same gearing, and they both appear to be LS, then I will be leaving it alone for now. I might swap the leaf springs and blocks over, but I know that my rear axle assembly is in very good condition, and so will continue to run it and keep the other one as a spare.

As my truck is a bit of a frankentruck already, am going to check the gears directly before I do the swap, was told I could do this by jacking up the rear end of both trucks, and comparing the amount of revolutions of the driveshaft versus the amount of the revolutions of the wheels, and comparing the results with both rear ends. If same, then same gearing.

Someone also told me that I need to drop the rear axle to swap the leaf springs. Is this true?

Thanks for all the input! very helpful.

 

don't HAVE TO. i changed the springs in my 88 when i had the bed off.
cut the u-bolts, unbolted the springs out of the hangers, lifted the broken spring out. put the new spring in, bolted them up. then did the same on the other side and dropped the bed back on.

quick rear axle id:
sterling has 12 bolt cover.
dana has 10 bolt cover

 

Also, F250 and f350 use the SAME 5 leaf rear springs

 

Well is it really just the blocks that is the difference? My 350 springs seem to be quite a bit beefier than my 250. And have more springs, instead of 5 and 1 helper it is 6 and 2 helpers

 

Someone put an add-a-leaf in. No such thing as 6 leaf springs