Essentially the same trans just a minor difference in the placement of the shifter and such but the length and the bellhousing to trans bolt pattern should be the same. From what i found the ax15 is stronger than nv3550 (or just had less issues). I wish I had the forums saved but Google will produce the results. Most of the info i found was on the jeep forums. Im at work from 7am to 9pm every day so when I get some time I'll find the threads which the info

 

Quote:

Originally Posted by shadowthedakota

From what i found the ax15 is stronger than nv3550

I too, have read that on some of the jeep forums, I just dont believe it, and here is why.
Assuming the 3550 is the same transmission as the 3500 (torque capacity)

In 87 when dodge came out with the V6 4wd dakota, they used the NV2500 transmission. This was used through 91?
In 92? they changed to the AX15 which was used behind the magnum V6 engine, and continued to be used through 99? for the V6 5spd dakota's
In 94 or 95 when dodge offered the dakota with a V8 and a 5 speed, the transmission was the NV3500.
In 2000? dodge started using the NV3500 in all 5 speed dakotas, both V6 and V8 until they switched to the 6 speed, 2005?

In short, looking back at the history of the dakota, Dodge saw a need for a stronger transmission behind the V8 and choose the NV3500 over the AX15 .
Thats my 2 cents worth!!

 

I can see that. With the exception of the swappable bellhousing though, I ran a stock ax-15 behind a top-swapped l36 (supercharged 3800) and it held up fine to 300hp 290tq turning 35x15.5 boggers in my 87 suburban after the sbc 350 failed. I can also see Chrysler being as wierd as they were just changing manual transmissions like that because they wanted to see what worked and got lazy and left it. Nv3550 failure, from what I've seen in the off-road community, is quite common but I have yet to see a stock nv3500 fail whether it's gm or Chrysler. I have seen nv4500s fail though, that was behind a Cummins diesel and from metal fatigue.