The Shop > Axle / Differential

The 1980-83 Right Rear Axle Problem Struck Again

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KIV_6051:
Thankfully the axle snapped at the hub at a relatively opportune time and place.  I took the AMC 15 rear-end to a custom drivetrain shop and was informed by the technician that rebuilding it wouldn't be financially feasible compared swapping in a Dana 35 from a Jeep XJ.  The technician explained that a Dana 35 from a 1993-98 Jeep Cherokee would most likely be best since it appears to be bolt-on (with 5 x 4.5" hubs and minus the shock mounts of course) but I want to make certain I buy the right part the first time.  He also explained that if I want to keep my 3.31:1 gear ratio, I'll have to get a Dana 35 that has a 2.73:1 differential housing (carrier) since it should be identical.  If I can't locate an AMC 15 from a 1984 Eagle or a Dana 35 from a 1985-88 Eagle in good condition, what year or year range of XJ would have the most feasible replacement?  At the very least, is there a Jeep model year or year range I should avoid?

Additional concerns:

Axle width: the 1998 Cherokee (compared at the drivetrain shop) has an axle housing that is flange-to-flange wider than mine by about 3/4".  How far can I deviate from the stock Eagle AMC 15 width?

Comparable brakes: I was told by the technician that I shouldn't have to worry about the replacement brake assemblies being disc or drum and I shouldn't have to replace the proportioning valve.  Can anyone confirm this?

Transfer case: after the right rear axle snapped off, the Eagle was towed by the rear-end without a tow dolly on the front wheels for about seven miles at a max speed of 35 MPH. 
Is there a way I can test the existing transfer case with the rear axle removed?
I have the original 1981.5 Select-Trac NP129 and if this tow fried it, will I be able to keep my stop-and-shift system if I swap the transfer case with a NP229 or NP241?
If I do need a new transfer case, wouldn't I be better off replacing the 3.31:1 gears anyway with 2.73:1 gears since the replacement transfer case would have a low and high range?

AMC of Houston:
Gotta ask .... why don't they want to just simply swap in another axle??    That would be the easiest cheapest route I'd think.

KIV_6051:

--- Quote from: AMC of Houston on June 08, 2023, 10:07:29 PM ---Gotta ask .... why don't they want to just simply swap in another axle??    That would be the easiest cheapest route I'd think.

--- End quote ---

The two-piece axles in the AMC 15 are obsolete and nobody makes tapered splines.  The technician explained that he used to replace two-piece axles in Jeeps with Ford 9" style axles all of the time.
The other problem is the rear-end needs to be rebuilt, and while there are plenty of AMC 20 rebuild kits out there there are no AMC 15 rebuild kits.

Basically my best option is a most-common best-match Dana 35 that can be rebuilt now and later down the road.  Any help would be greatly appreciated!

Illeagle1984:
I can confirm a rear diff master rebuild kit part number.  Motive # R35JRMKT is listed for a Dana 35, but I remember all the bearings were correct.  Axle seals sold separately, because there were different kinds throughout the AMC 15/Dana 35 dynasty. 

The bigger issue is, of course, the axle shaft .  I'm curious which axles your tech was putting in.  Were they clipless Dana 35 axles?  I could see it working if the length and splines match up.

KIV_6051:

--- Quote from: Illeagle1984 on June 09, 2023, 09:52:11 PM ---I can confirm a rear diff master rebuild kit part number.  Motive # R35JRMKT is listed for a Dana 35, but I remember all the bearings were correct.  Axle seals sold separately, because there were different kinds throughout the AMC 15/Dana 35 dynasty. 

The bigger issue is, of course, the axle shaft .  I'm curious which axles your tech was putting in.  Were they clipless Dana 35 axles?  I could see it working if the length and splines match up.

--- End quote ---

That's great info and I'm glad there's still a way to rebuild an AMC 15!

I believe the custom axles were clipless since the technician explained that the two custom axles would cost about $600-800, not including having to modify the axle tube flanges, modify the backing plates, and rebuild the rear-end due to backlash in the ring and pinion.

I will try my luck searching for a Dana 35 from a 1985-88 AMC Eagle with 2.73:1 gears to rebuild with 3.31:1 gears as it would ultimately cost less (~$400 + shipping and rebuild). 
Would anyone know off-hand where I could find an auto salvage yard in or around Oregon likely to have Eagles?  It doesn't have to be in the Pacific NW but I'd like to minimize shipping costs if I could help it.

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