A904 question

[signalb]

Hello,

I have an 86 MJ with the 2.8 60 degree v6 and a904 transmission. That engine is part slug and part cockroach but the slug in it needs to go so I'm planning on upgrading to the 3.4 complete with a weber 38 and headers after Christmas but my transmission has been on the fritz since day one when I got the truck a year ago. I know the A904 came with three different bell housing bolt patterns for Jeep. One of those was for the 2.5 AMC 4 cyl and the 2.8 gm v6 which shared the same bolt pattern. The question I have is if I can find another a904 in the junkyard that was used with the 4 cyl will it be the same transmission as what I have now or are the internals/torque converter different? Basically an a904 that was mated to the 2.8 is impossible to find locally and $100 for a salvage yard tranny is cheaper for me than a full rebuild of my existing one so if one off a 2.5 will work then I'm in business.

Thanks,

Dave

[mjeff87]

I'm fairly certain that all 904/909's have the same bolt pattern and share the same internals, but beware that later model ones that came behind the 2.5's in YJ's have a 23 spline output (if yours is a 4WD). THey will bolt up fine, but if you have a 21 spline transfer case (input), you'll be going nowhere in a hurry..... :yes:

 

Jeff

[dasbulliwagen]

Youll need to make sure the input shaft is the same splines, and the same length too, and have the same pilot bushing size.

[signalb]

Ok then if I just grab the whole assembly from the yard I could upgrade the transfer from the current np207 I have to the np231 and snag a newer(ish) tranny at the same time right? What about the torque converter? Did they all use the same one or is that different from year to year and/or engine?

[mjeff87]

automatics......the 904 is a 3 speed, 909 is the same tranny but has an OD

 

you just have to make sure that the TC snout OD and length are the same :thumbsup:

 

Jeff

[mjeff87]

Ok then if I just grab the whole assembly from the yard I could upgrade the transfer from the current np207 I have to the np231 and snag a newer(ish) tranny at the same time right? What about the torque converter? Did they all use the same one or is that different from year to year and/or engine?

 

to be safe, I would grab the whole setup (flexplate, torque converter, tranny) and possibly the TC. Check the output shaft on yours first, should be 21 spline since you have a 207. Depending on the year of the donor, it could be either 21 or 23 spline (almost certain it'll be 21 if coming off an XJ/MJ)

 

Jeff

[dasbulliwagen]

Ok then if I just grab the whole assembly from the yard I could upgrade the transfer from the current np207 I have to the np231 and snag a newer(ish) tranny at the same time right? What about the torque converter? Did they all use the same one or is that different from year to year and/or engine?

 

to be safe, I would grab the whole setup (flexplate, torque converter, tranny) and possibly the TC. Check the output shaft on yours first, should be 21 spline since you have a 207. Depending on the year of the donor, it could be either 21 or 23 spline (almost certain it'll be 21 if coming off an XJ/MJ)

 

Jeff

 

I have an 86 XJ with the 904, and an NP228. Ive been told that since it has the NP228, it will have 23 spline output. I have yet to verify this though, so make sure you know what youre getting.

[signalb]

Thanks everyone! Time to go hunting in the salvage yards.