M939 Transmission problems

[Anthony940]

I have the opportunity to purchase a M939 with a bad transmission. Has anyone here ever rebuild one. I have experience with small truck transmission (4L60E) but nothing large. Any idea on cost or specialty tools that I would need / availability of parts would be greatly appreciated. The truck itself is in very nice shape and is showing 20k. No idea what is wrong with it other than it does not go. Thanks.

 

[Cruceno]

Simple question, but are you sure that the transfer case is in gear as well? Engine running, transmission in gear and transfer case not locked into gear equals no go as well...

 

[Anthony940]

The guy who owns it has had a number of large military trucks so I am confident that it is not something as simple as that.

 

[rtk]

If after you check everything out , follow the TM's there is a procedure , that will help narrow down what is defective in the Alison . The unit can be rebuilt , BUT , BIG and HEAVY and you will require some special tooling . I think the bigger problem will be if you need a lot of HARD PARTS , seals and clutch's are one thing , hard parts can be VERY expensive . If you really need a trans. I would look for a LKQ or NOS unit . Just my 2 cents .

 

[Doomsday]

Yeah, I would try to find one off auction cuz a remanned unit will run upwards of $2600 plus core charge.......I have seen great looking used and remanned units go for as low as $300 on auction......just gotta search

Joe

 

[jcappeljr]

I have a trans in a running m931a2 truck I would sell for $1500.