Auto to manual swap

-
Captainkirk

Captainkirk

Old School Mopar Warrior
Joined
Apr 24, 2006
Messages
3,371
Reaction score
1,510
Location
Northern IL
My kid's been trying to talk me out of my spare 4-speed to put on his '74 318 Duster. (He talked me out of my extra brake/clutch pedals already) My question is; will a manual trans retrofit on an auto trans crank without having the pilot bushing bore reamed oversize? According to the Taylor/Hofer book ("How To Rebuild Small Block Mopar Engines"): "Cranks used with manual transmissions have a pilot bushing bore 1/16 larger than torque converter pilot bore used with automatic transmissions" If indeed so, does anyone make a thin-wall bushing for this purpose?
 
It depends on the year. A lot of the earlier forged cranks were drilled for the pilot bushings regardless of whether they were in automatic cars. Later cast cranks intended for auto's often weren't, so the pilot bushing will not fit deep enough into the crank.

The solution is to use a later Dakota pilot bearing, which fits into the outer register of the crank. The only issue in doing that is the input shaft sometimes needs to be shortened a bit to avoid interfering with the crank. After the input shaft is cut down, you can only use the later pilot bearings and not the original bushings.

Looks like this

PB5300-1.jpg


http://www.brewersperformance.com/proddetail.asp?prod=PB5300&cat=16
 
Thanks, guys! Good to know. I was hoping someone made an aftermarket cut-down bushing, but this should work as well. Thanks coming your way.
 
You must log in or register to reply here.
-

Back
Top