258/4.2 crankshaft

ytradio

YJ Enthusiast
Joined
Aug 24, 2021
Messages
433
Location
WV
I have an 89 basket case that I have found out by accident was originally an auto trans. YJ. It came with an AX-15 & np231 laying on the floor of the guys garage. It’s a long story, but the bottom line is that the last known owner that was driving it told me that the AX-15 was bad because he claimed it kept eating up pilot bearings. It has a new clutch pressure plate slave cyl. Installed, and another new set in boxes. The pilot bearing is a needle bearing type. The real question that I have is, are the rear of the 258/4.2 crankshafts the same on the rear for auto and man. If so I believe that I may just need a different pilot bearing/ bushing.
 
The data I see indicates their the same. But Im sure others will chime in on that question. Aside from the crank question you might consider checking/replacing the AX input bearing or mainshaft bearings. Id also closely check the end of the trans shaft with a dial indicator to see if it has runout from somebody screwing it up it from a bad clutch installation.
 
Yea, I am going to get into the trans at some point before everything goes back together. Possibly replacing with a rebuilt. It does seam to shift through all the gears and turn the output shaft. I was looking at Novak the other night and could not determine for sure if a pilot in a auto crank would be possible without making something fit. I have been through this same thing with a 4 speed swap into an old Cutlass that was auto many years ago. I had to find something close and then have it turned to fit. It will be great if both cranks are the same this time around.