boc23

Hi,


I have a 4 speed m20 muncie with a 350. I found a "to good to be true" deal on a olds 455! Here is my question. Can the crankshaft be machined for the pilot bearing while in the motor or does it have to be removed?

BillK

They make a "conversion" pilot bushing that goes into the hole where the torque converter pilots BUT >>>>>> if you go that route you either have to drill a hole in the crank for the trans input shaft to go into or cut off the trans input shaft so it isn't as long.

I am sure if you tried hard enough and made some type of fixture you could machine the crank in the car for the proper throwout bushing but I would imagine it being a fairly difficult job. I have done one in the lathe and it still isn't the easiest setup in the world.

1966442

Take the new pilot bearing and the crank shaft to a machine shop and they can machine the crank shaft to accept the bearing
I have had it done a few times

oddball

Conversion bushing is the quickest option. The clearance hole for the nose isn't precision, so can hand-drill. This method has been around a long time. I would be worried about durability on a daily driver, but that's probably not what's happening here.

Don't try to hand-drill for a real pilot bearing - it won't go well. Gotta pull the crank and go to the machine shop for that.

maddoctor

I agree , let an automotive engine shop do this, not for the novice. My engine shop opted for the conversion route. They didn't want to cut in too deep and weaken the area.

joe_padavano

Considering the factory cut that deep for MT cranks, I question the wisdom of your engine shop.

maddoctor

[QUOTE=joe_padavano;1474697]Considering the factory cut that deep for MT cranks, I question the wisdom of your engine shop.Ok.