Understandably after ¼ million miles my 5-speed is a little tired and sloppy! (’96 sport 4wd 5-speed man for reference)

I am also seriously considering swapping the 3.9 for a mild-build 5.2 maybe as soon as spring of ‘22.

So I need some advice on the gearbox today!

First, there’s a gearbox with new clutch on CL for about $300, but it’s out of a 2wd machine. From what I see, it looks like they are the same component – AX15. True?

Next, I can buy reverse and first if needed (kinda spendy tho!) but a rebuild kit with synchro’s is available at Amazon for less than $200. FYI, I have seen “new” AX15’s advertised for about $1700, and it’s worth considering if parts and my labor end up close to that…

What about any internals that may need upgrading? I’m hoping for about 300hp for the 5.2 when it’s all done, so that may be a consideration for the gearbox, but I am not much of an off-road guy. The truck is transportation/hauling/winter bug-out machine.

Thanks for reading, and all advice is appreciated!

 

The tailshafts are different between the 2WD and 4WD transmissions; check the factory service manual (downloadable from the link in the FAQ message)

Shucks, it's got the rebuild instructions in there; grab it for that if nothing else!

Depending on how you drive it, you may be perfectly happy with the AX15 behind that 5.2 .

I'd check into the Jeep forums for what they suggest doing to a AX15. I think it was behind some Jeep motors also, but am not positive on that.

Do plan on rebuilding the transfer case also!

RwP

 

Sounds good Ralph, I will do those things.
I the gearboxes I found for sale were marketed to the jeepsters so I'm pretty sure they're comparable/identical.

 

You may have to swap bell housings; the AX15 might have ended up behind the 4.0, which is a completely different pattern.

But that's no step for a stepper

RwP