Trans Swap

[kenwheeler]

My current 5 speed tranny is busted. I have an 87 2.9 4x4. I found another 5 speed out of an unknown year 4x4 with a 2.9, its an FM146. The only difference I can see between the two trannys is the hydralic connection, mine is a hard to get to connection on top of the bell housing and the donor tranny has a quick disconnect coming out the drivers side of the bell housing. I checked the tech trans swap page and I believe it said all 4x4 2.9 5 speed trannys are interchangeble.

Will the FM146 replace my grenaded FM145? I also noticed the donor tranny used an electric shift transfer case, mines a manual shift.

 

[Insanejughead]

OOooh... There's alot I want to tell you, but I'm not very well acquainted with the entire "4x4 - FM series transmissions - pros&cons" scene.


Overall, you should be able to replace one with the other. I think you would be able to keep your manual shift transfer case and just swap out the transmission BUT I don't know how long they are compared to each other. That could prove to be the only real problem you have there.

Which, if it is, then a driveshaft SHOULD be the biggest thing you have to change afterwards.


Oh, and the hydraulic lines are easily replaceable. You could either change out the connector on the end, or just find the donor vehicle again and use the entire hydraulic setup. I like the quick disconnect fitting on my tranny. You will too if everything else works out.

Lastly, all transmissions in the 2.8-2.9-4.0 family will bolt up in place of the other. The only thing you have to worry about is the length when factoring in the driveshaft.


I hope I helped, but don't take my word as gold on any of this. Someone else should chime in pretty quick here.

 

[martin]

transmission lengths and interchangability are listed in the tech library.

 

[kenwheeler]

ok, thanks for the info. This is the second transmission I got for this truck. The 1st was out of a 2 wheel drive and would've taken much part swapping to make it work.

 

[Andres629]

The biggest difference you will find is the FM146 is 2" longer than the current FM145. This being said, seeing as you have a manual shift t-case, could cause you problems with the linkage. Second, you will have to A) find a front and rear driveshaft from a post 88 truck that is the same wheelbase as yours, or B) get your front and rear driveshafts lengthened. I was looking at the same thing and got a lot of great info on it.

 

[kenwheeler]

I gotta find driveshafts too? Wow, the Tech Library should include some *'s with some of the info. I was under the impression these trans would swap without additional work. I guess I'll have to pickup some driveshafts also. Oh well, whatever.

Is there any transmission besides the FM145 thats in the truck now that will swap out without changing alot of other stuff?