This info came from "http://bigbroncos.com/jeep/tech/mj.htm". I copied it here becouse I was afraid it might get deleted on there server. this is to big of a welth of info to loose.
Drive train
DescriptionThe Comanche (MJ) was produced from 1986 until 1992.
The Comanche is similar in many ways to the downsize Cherokee (XJ).
Engine The MJ came with the AMC 2.5L I4 engine standard and the GM 2.8L V6 optionally in '86. The AMC 4.0L I6 was introduced in 1987. Transmission The AX-5 and BA 10/5 were used with the I4 and V6. The BA 10/5 was discontinued in 1989 and the AX-15 was used with the 4.0L I6.Information on automatic transmissions will be added later.
Transfer Case The NP-207 was used until 1987, after it the NP-231 was used.The NP-207 and NP-231 are the Command-Trac transfer cases. The other transfer cases will be added later.
Front Axle The Dana 30 was used as the front axle in the MJ. Rear Axle The Dana 35c is the axle most commonly found in the rear of the MJ. The Dana 44 was optional in some models with the "metric ton" package.