Xfercase/Transmission ID and HELP

[Old Yeller]

OK, I'm having a hell of a time with separating the xfercase from the tranny. First off, is this actually a np231 mated to a AX15? It is a 4.0L 91YJ (Originally thought to be a 93), with a 5spd.

I have an AX15/np231 on old yeller, but they don't seem to look the same? Whats with the big balancer at the end?

Also, why the hell arn't they separating??? All 6 nuts are removed (and all 6 studs with them), and the thing just spins in relationship to the transmission, but no amount of prying is getting it to come off. Am I missing something, or is there a nice trick?

Heres the pics:








Thanks!
Rob D

[justajeep]

That's not an AX15. The T-case is TJ, so I would say the trans is too, a NV3550.

Not sure why it won't come off, usually it's corrosion around the studs holding them on. Maybe if it sat a long time moisture in the trans rusted the splines together.

[Old Yeller]

Yea, its very possible that its a different geartrain than original, the balancer on the end really threw me off. The rear DS looks to be cut short as well. This would also explain the cobbled up t-case linkage, and reverse shifting order I'm used to.

I wanted the transmission as well for a replacement for my syncroless AX15. But now I'm wondering about driveshaft lengths, and if the NV3550 is as good as the AX15... Again, nothing goes as it should for me it seems, lol. What fun would it be if everything went as planned lol.

I'll likely pull the trans/tcase out as one, so I can go ahead with the motor swap.


New question. ASSUMING I can separate the two without damage, and the tranny is of similar length, how are the NV3550's durability? Seemed to shift fine, albeit a tad sloppy when the jeep was running.

Rob D

EDIT: Some Internet searching answered some of my questions. The NV3550 came out in 2000 as a direct replacement for the AX15. It is only 0.2" longer, supposedly more durable, has an external slave, and a deeper 1st gear. I can't find any negatives there, lol, so I'll be doing my best to save this thing.

Also, the jeep has sat for years, so the splines could well have fused together. Still have to figure that out.

[Stevens]

They are stronger than the AX15.....they used the nv 3500 behind the v8 dakota's and the nvg 3550 is suppoesedly stronger rated at 300 ft lbs while the ax15 at 250. They do have issues popping outta gear.....the shift shaft wears where the detents balls fit into the shift shaft detents, cause it to pop outta gear.

[Old Yeller]

Maby that is why it felt a bit sloppy shifting gears. Almost like its too easy to shift. Is it something that can be replaced through the shifter tower? Or internal to the tranny?

Rob D