T86 Rebuild

Hey Guys,

I've got a 3A that I'm swapping a 225 into. I'm at the point in the build where the motor is heading off to the machine shop soon, and so I'm turning my attention to the rest of the power train. Specifically, the tranny.

I know the T86AA isn't the worlds best transmission, but I'd really like to have this thing on the road sometime soon, so I think I'm just going to put a little bit of money into it with a small parts kit, gaskets and some bearings. Can anyone recommend a decent rebuild manual for that transmission, or is it close enough to the T90 to use that as my guide?

 

Or would it be worthwhile to get my hands on a 90 and swap the guts into the 86 case?

 

If your T-86 guts are in good shape then use them. If not then the T-90 is a good conversion and parts are much more available. You must also change one shift fork in the shifter top to make it work right.

Hermtheoverdrive.com (Herm Tilford) offers quality rebuild kits for these as do many other resources like Novak Enterprises.

 

Well that's the thing, the 86 is pretty beat. Some teeth are chipped and as has been noted, parts are hard to find and pricey. Id like to swap in an sm420 in the next couple years, and i'm hoping the 86 has a couple more years in it. So will a rebuild guide for a 90 be close enough?
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check this
http://www.cj-3a.com/T-90 Rebuild.htm

 

So I guess the question is , are there any important differences between the T-90 and T-86 rebuild? Or do you need the Jeep TSM for the T-86?

I don't know for sure, but I think if you have one that's together and working, you can use it as a guide to reassembly. The basic process will be the same for the T-90 and the T-86. There may be minor differences, so keep track of what whent where and in what order when you disassemble. Typically your small parts kitt will come with a sack of a bunch of different snap rings and rollers. Use a caliper and measure the old parts to be sure you pick the right new replacements.

Not sure how much benefit you'll get out of the small parts kit if the lifetime of the rebuilt transmission is espected to be short. If it shifts ok now and is not noisy, I'd be inclinded to just use it. The usual high-wear items are the blocking rings and the front main bearing. If it pops out of gear now, a small parts kit won't help that.

One option would be to send the whole transmission to Herm for exchange. That would put a ceiling on your costs and insure a proper functioning transmission. I expect you could get about half of your purchase price back by selling the rebuilt transmission when you decide to go to a SM4xx. Then if somethng in your life changes, you won't be locked in to replacing a sketchy T-86 in the near future.

 

I don't really know how the transmission operated prior to being torn apart. It came to me partially disassembled, which tells me that there may have been an issue. Visually it looks complete, but the mainshaft, rollers, gears, synchros, etc are in a box. I guess it can't hurt to take a shot at rebuilding it, especially if its going to be replaced soon anyway. Thanks for the help guys.
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