OK OK OK - maybe not hardcode, but I tried this in the newbie section, and they are, well, newbies so nobody knew...



I just rebuilt my 4.0 from a 93 and ended up swapping in a crank from a 4.0 that is (I believe) an 1988. The casting numbers on the two cranks are identical.

The area where the pilot bearing for the transmission input shaft is supposed to be pressed in is too large (BTW, I'm using an AX-15). I've read two different stories and there are two different pilot bearing part numbers for the diffferent years, so if someone can point me in the right direction that would be great.

Story #1: The bearings are simply different. Buy the bearing for an 88 4.0.

Story #2: There is a sleeve pressed into the crank, and the pilot bearing is pressed into the sleeve. Machine a new sleeve and press that in.


I've looked at my old 4.0's crank and it almost looks like the part the bearing is pressed into is indeed a sleeve - but I can't really tell. Tomorrow I'll get a slide hammer and try banging it out. Or maybe I'll just break the hammer.

Soooo... can anyone shed some light here?

Thanks!

Story #2 is correct. If the 4.0 you are putting in had an auto behind it before, then you are going to need the "sleeve" for the crank. I went through this when I was installing an auto in my TJ and had to cut the sleeve out for the torque converter to fit. Auto wasn't for me, so I purchased another sleeve through Jeep and I think it was only $50 or so and came with a new input shaft bearing.

I did something similar and ended up using a waggy bushing, sorry, do not know the part number and year, I just did some measuring. In my case the inside diameter and outside diameters where off. I had a 91 Yj with a AX-15 and went to a 95 YJ Ax-15, they had different diameter output shafts.

More info here:

http://www.pirate4x4.com/forum/showthread.php?t=267393


Ok, to add to the thread, here are pics of the input bearings that would go on the flywheel, showing the difference:

The bottom left is a 95, the bottom right is a 91, and the top gold is a Grand Wagonner, which has the outside diameter of the 91, and inside diameter of the 95, so that is the part you will need in the event of a swap, if the tranny shaft diameters differ from one another.

http://img.photobucket.com/albums/v256/geberhard/bushings.jpg

what is the od of your tcase input shaft that rides on the bearing.. what is the id of the crank.

I have a bunch of brand new pilot bearings of all the differnet sizes, from the last time I played this game. If I have one that is the size you need ill send it your way.

dan

DozerDan - Thanks very much for the offer. And thanks to everyone else for the heads-up.

I'll go the stock route and press in the right sleeve. Maybe I can pull out the old one, or at worst hit the dealership.

Again, thanks everyone for the info :)