T-86 &T-90 Similarities

OK, I thought I had the T-90 in my 66 w/ a 225, but from what I have read it should be the T-86. I just can't get to the case to see what is stamped on it. I'll find the time soon. But I already have a small parts kit for a T-90. Can I use it in the T-86? What were the major differences in the trannies?

 

T90's were never installed behind a v6 in a jeep from the factory. From what I understand there are to many differences to be using the parts in a t86, synchros, bearings, pretty much everything is different.

 

I don't know about the parts kit, but if you're lucky, you'll still have the transmission tag under one of the top cover bolts. Pretty easy to get at - take off the transmission cover on the floor. There're no stamped numbers AFAIK. There should also be numbers cast into the case - somebody here can probably interpret them.

 

Mine may be an exception, but I seem to remember it having T90A ???? stamped on the driver's side of the case just under the shift tower.

I *think* you can see it from under the Jeep, just take a clean rag with ya...

 

There is a link to small write up about the T-86 and T90.

http://www.off-road.com/jeep/tech/trans/t86.html

You should be able to see the casting # on the transmission case if you take the floor/tranmission cover off. The casting # is on the upper driver side of the case itself. Mine says T86AA - 18 and there is a serial # under it. There will be a casting # on the shift tower/top cover (mine says T90-14 b, interchangable parts???), that won't be the correct number. Look on the actual side of the case. Make sense?

As far as parts being interchangable, I thought parts from the T-86 could be used in the T-90, but not the other way around. Thoughts/comments.

 

My old t86 had t86 on the drivers side

 

Based on what I have read around here, you will never know whats inside untill you take it apart. Original Early 5 transmissions were not very strong, and have often been rebuilt with scrounged, swapped in parts. Just an observation.

 

I did the opposite, my case was marked with T86, I bought a small parts kit for it, opened it up and the guts were a T90. These Jeeps are little puzzles sometimes!

 

I know what you are going through, I myself just went through that. I lost my t 86 in my 67. i had a t 90 from an f head. so i rebuilt my t 90. all i needed was a different maindrive clutch shaft. big mistake i must say. i should have rebuilt the t 86. it has a spiral cut mainshaft, opposed to the t 90's straight cut mainshaft.If your tranny pops out of second gear when you go down a hill you definately have a t 90. the cases are nearly identical. but i don't believe the small part kits are the same. i will check out my old parts from both trannys and get back to you

 

the syncros for a t86 are bigger than those for a t90. The cluster gears for the two have the gears cut the opposite of each other. I believe that if you are going to swap parts from one to the other it's all or nothin. if you need some spare parts for a t86 I may have a main shaft and a main drive gear if you are in need.

Rio