I did a 5 speed swap in February with a transmission from a 1990. Honestly, it was the first 4x4 ax15 I'd found in years, so I jumped on it. Unfortunately, the pilot tip on it was not the right size for my 98. However, Novak makes a conversion pilot bushing to fit that exact application, so I ordered it. Fast forward to a day ago, and I start getting the signs of a bad pilot. It was noisy when the clutch was disengaged and the transmission in gear. So I pulled it out and sure enough, there it is. Chewed up and galled.

Things to note:
-Since it's Oilite, I didn't install any grease on it.
-I checked the runout of the pilot bore (as recommended by Novak)
-Of the literal hundreds of pilot bearings or bushings I've installed, this is the first to fail. Ever.

Anyone else had this experience?



I didn't call Novak for one reason only. It's my daily, and I need it back immediately, and I couldn't wait for another one from them. I decided to swap input shafts from a 95 AX15 (2WD) I found in the local JY, so now I'll be able to use the correct pilot bearing for my application. It's already installed, just have to finish up once the rain stops. Yes, way more work, but far less downtime.

 

Update:

I contacted Novak. They asked for pictures, so I sent them several. I haven't heard back yet. I'm hoping they ask me to send them the bushing. I'd be interested to see what caused the failure.

That being said, my Frankenstein ax15 is doing great.
1990 xj transmission
1997 xj bell housing and Input bearing retainer
1995 Dakota input shaft

 

In general, the second check would have been bolting the bellhousing on the engine and make sure it centers as needed..Some need offset dowels to correct slight misalignment between the trans input shaft and the pilot bearing..

 

I'd be really surprised if that were the case, as I've never even heard of that until now. So I go and do some research and sure enough, it's a real thing. It's even got a procedure on Novak's website.

Except...

How would you do that on an AX15? There's no concentric bore on the bell housing. It's a weird oval shape. I really can't even begin to think of a way to do that with this bell housing. I did some more searching and found a thread where a guy asked the same question, but it went dead. No answers in any of the (few) replies.

I guess I'll probably just wait and see what happens. Maybe the bearing will go the long haul?