I tried to do a search on this and I couldn't find anything other than axle swaps and then I couldn't figure out which one would fit into my 87 raider with an automatic?
I ordered the new seals and such for the front of the 3rd member from Rockauto.com and installed them but I still cant get them too stop leaking around the shaft.
I got the old race out and made sure the third member surface was perfect and I made sure the driveshaft didn't have any grooves in it either.
I dont know what to do now except order another set of seals and try again or do the swap that has the factory locker if I can find a deal on a whole used assembly?
Can you guys think of anything else to try? This thing is slinging oil all under my truck while driving and leaking slowly in little puddles overnight?
Everything else on the truck works perfect and I just want to be able to use it as my commuter once in a while when I cant ride my motorcycle without catching fire or burning up my rear diff due to lack of oil.

As a stop-gap, find ANY junkyard axle out of the same vehicle and swap. They're not hard to replace as a unit.

EDIT: Any leaf-sprung Montero/Raider with a four speed automatic or a 5-speed manual after 1986 will work. Pre-87's (at least with the automatic 3-speed) came with a different differential ratio.

Something's either not fitting correctly, or there's a scratch/debris in there that may (just maybe) have been missed.

John B.

I had the same issue with my rear pinion. Looked at the FSM and seen the special tools required. Almost ordered them too. Then I tore a tendon in one of my fingers leaving most manual work difficult or impossible. So I paid a local tranny shop to change it out for me with the seal i also got from Rock Auto... IIRC, it was a National brand seal.

It's been almost 4 weeks now and no leaks.

As previous poster said, could be dirt/debris either from installation or some junk that was in the diff. I'd do as he suggested, either unbolt and swap, or at least unbolt, remove seal and drain oil and flush out the diff with some sort of cleaner (suggestions from the board?), then really clean that seal mating surface and put it all back in.

My cost was $110. Basically an hour labor (@$70) plus the gear oil to refill. Had I not provided the seal I imagine it would have cost me another $20 or so.

Jim

The edit part is what is important here. I highly recommend looking for one with the air locker and the disc brakes. If you've got big tires ( I have 35's) When you get the swap done, you will be amazed at how much better it stops.

Vent.........? Pluged

Good call David. If the breather is plugged, it'll puke from the next easiest place...