Correct Pilot Bearing For Early Ax-15 With Auto Crankshaft?

[1987Comanche]

Tonight I discovered the crank in my reman engine was apparently originally in an AW4 equipped vehicle. The Renix AX-15 crank apparently used a .945" OD and .591" ID bearing:

http://www.napaonlin...5446_0072572747

 

I'm converting the trans to an external slave and have a clutch kit for a '96 XJ. Pilot bearing OD is 1".

http://www.napaonlin...B128_0072575625

 

I knew the ID would be off but I wanted to check the OD. The engine is on the stand so I can't get calipers to the back of the crank. In theory there's no way the 1" OD bearing would fit. It dropped in and didn't make contact with the ID of the crank at all.

 

This leads me to conclude that the crank was originally hooked to an AW-4. NAPA lists a pilot bearing for an AW-4, even though that doesn't make a whole lot of sense (why would an auto have a pilot bearing?)

http://www.napaonlin...B657_0072572740

OD is 1.1", ID is .590"

 

So I'm assuming I need to use the pilot bearing they list for the AW-4? ID is 0.001" off and the contact length is greater. Will either of these make a difference? Has anyone else run into this?

[a.e.]

1974 CJ WITH A 304 PILOT BUSHING... DORMAN # 14674 BCA/NATIONAL # PB77 OR PB77-HD

[1987Comanche]

There is no crank difference between the Renix M/T 4.0 and the A/T 4.0. There is, however, a difference between the Renix crank Dia and H.O. crank Dia. As you stated the correct pilot bearing for a renix running an internal slave AX-15 is .590 ID and 1.1OD. H.O. pilot bearing used for external slave AX-15 is .75 ID and 1.0 OD. If you are mating an external slave AX-15 to a Renix engine you need a 0.75"ID and 1.10" OD pilot bearing. You can, however, convert an internal slave trans to external slave, then the original .590" ID and 1.10" OD pilot bearing works just fine.

[Geonovast]

There is no crank difference between the Renix M/T 4.0 and the A/T 4.0. There is, however, a difference between the Renix crank Dia and H.O. crank Dia. As you stated the correct pilot bearing for a renix running an internal slave AX-15 is .590 ID and 1.1OD. H.O. pilot bearing used for external slave AX-15 is .75 ID and 1.0 OD. If you are mating an external slave AX-15 to a Renix engine you need a 0.75"ID and 1.10" OD pilot bearing. You can, however, convert an internal slave trans to external slave, then the original .590" ID and 1.10" OD pilot bearing works just fine.

 

This is mostly right.

 

While it's pretty safe to say the distinction is Renix/HO, it's off by a year. 1991 uses the Renix setup.

 

Just an FYI.