Borg Warner T-35 (probably shot)

AMC autos transitioned to the Torgueflite automatic trannies in 1972, but your 1972 casting number block and the fact that you have a BW tranny means that you have a special bellhousing.  Your block should be capable of accommodating a torqueflite tranny.  AMC 904 trannies are pretty common so that's what I would look for if you want to get away from the BW world.  I suggest that if you find a torqueflite, that you also get the shift linkage and kickdown linkage that came from the same car or Jeep.  Jeep pretty obviously did something special for the Postal Jeeps. 

Thanks for all of your replies, fellas. Not good news on the diagnosis, though.Dropping the pan revealed more "glitter" than a new years eve party and metal shavings in all the fluid. On the positive side, the valve body and tubes look OK. So now it's decision time...
I can either rebuild the M43(T-35) or look for a replacement. I'm wary of a replacement because, without a dynamomometer test or unless I pull from a running vehicle, it'll be a crap shoot. Even then,tranny health is a matter of fate, right? Rebuilding myself (I wish...), paying a hobbyist (no warranty), or paying a shop (more money, but ATRA warranted work) are the other options. I'm leaning toward the shop and am willing to bite the bullet if only because I can't stand the thought of this vehicle being parted out or sitting in a yard forever. Being a 40 year old mail jeep, I expected to spend money up front to get the steering gear box, king pins and brakes up to snuff. I didn't count on this, but that's life. I think I'll look for a 258/A727 combo down the road if I can buy the vehicle right. When it's time to make that swap, I'm sure I'll be seeking your advice again. In the meantime, I'm going to get the broken/worn parts and study them with the TSM so I can learn for the "next time."
Happy new year, all.

Look at the bands and drums. You may need to drop a servo so you can rotate the band some to see the drum. If the drum isn't scored too badly the trans will be pretty easy to rebuild. It's not a hard one to rebuild yourself, just one or two little tricks to it. If you ever thought you might want to rebuild an auto trans yourself, this would be the one to try it on!

Thanks, Fellas. I'd never considered rebuilding a transmission myself. To be honest, It's never been on the radar, but I'm pretty sure it's above my skill level. This one is probably just going to have to left to the pros, which despite being pricey, will give me a lot more peace of mind. I'm going to try to handle some other projects (upgrades)on my own if I can find someone willing to show me a thing or two, but since I'm a complete novice, I really appreciate all your advice. Kirk: I'm way, way on the other side of town, but I have a friend whose uncle runs a shop that's also well regarded (knows old BWs too). I'll let y'all know how it goes. I'm looking forward to getting out to some Cactus cruiser events.

Edited by postdoc - Jan/05/2013 at 10:05am

If you can rebuild a motor, even a Briggs & Stratton, you can rebuild any of the BW transmissions. You need a manual and a good clean place to work. Helps if you have time to do it all over a couple days (pull trans one weekend, take apart/reassemble the next, and plan on two long days - a three day weekend is better, put back in another weekend).

There's a neat trick to getting the sealing rings back in the center support -- let me know if you change your mind about building it.