Transfer Case Seal Replacement (NP 231)

XJers.

The FSM indicates the nut, washer & seal at the front of the NP 231 cannot be re-used when removed. Are the washer & nut dealer items only?

Also, how do you prevent the assembly from rotating when removing the nut inside the front yoke? Is it easier to replace the front seal after I re-install the drivetrain in the vehicle?

Has anyone here found a robust solution different from these parts?

I have not removed the front yoke yet and wanted to ask these questions before it was disassembled.

Thanks,

Rick

Easy enough to keep it from moving - put the transfer case in low gear after you get the driveshaft out, and use the weight of the vehicle and the low gear ratio to hold the shaft in place whlie you wrench on the nut.

I don't know the size of the thread offhand - but if it's a fairly standard nut, you can probably go to the hardware store (SAE Grade 8 would be good here...) and get your replacement that way, or check out a driveshaft/driveline shop - they're bound to have them.

I haven't had a chance to review the applicability of other solutions yet (i.e. - I haven't had to replace that seal yet!) so I don't know anything else that might help you - but that's worth a shot.

I'm sure the nut is specified as "OEMR only) because it's a "deformed thread" nut - meaning that a couple threads are actually peened over to provide locking action. Taking a sledgehammer and a punch will work to peen the threads over, or a good grade of LocTite will also help. Don't bother with a split lockwasher - I've never had much faith in them. They work by (theoretically,) having the cut ends dig into the nut/surface, but the first thing that happens is it gets flattened. "Star" washers are a little more useful (internal or external teeth,) but LocTite or deformed threads are probably best.

5-90

Does anyone know what the size of this nut is (i.e., the front yoke retaining nut)? The FSM does not state the size. I've tried the following sockets unsuccessfully: 1" & 27 mm - too small, 30 mm - too large. I do not know of it's SAE or metric.

Thanks,

Rick

It is 1-1/8".

You can reuse the front output nut and washer without any problems. The seal can be reused as long as it isn't damaged during disassembly.

Hit the 1 1/8" yoke nut with an impact wrench and the yoke won't turn much. You can also make a tool like the FSM recommends to hold yokes while wrenching on the yoke nut.