52 Flywheel
 

I have been going through the process of getting things mechanically sound while I work on the cosmetics of the 52 I just picked up. It's a 215 straight 6 with a three on the tree (light duty). The long and short of it is that it shakes at low rpms either in reverse or first. When I picked it up the PO said that when he did the clutch a year ago he didn't turn the flywheel because he was worried that it could have been turned before and didn't know the tolerances. This leads me to a few questions:

- Do I have to take the engine out to replace the flywheel. The shop manual says that to work on the flywheel I should remove the engine.

- Where in the world can I get a new flywheel I haven't found anything but flywheel ring gears available. Whats the deal with that?

- How do I go about figuring out what the tolerances are for a flywheel?

Hopefully these aren't too stupid of questions. This is my first resto on a truck after building a few bikes.

Your flywheel would have to be really worn to be worried about tolerances. Resurfacing a flywheel only removes marbe .050" and you wouldn't need be worried unless you had to remove maybe .300".
To get the flywheel out you can leave the engine in the frame but you would have to remove the trans, clutch & starter and then the flywheel.

Are you saying it shudders or chatters when you are releasing the clutch? or is it shaking with the clutch all the way out at low RPM? Check motor and trans mounts before you go digging into it.

It shudders when I let it out. Once you get it in gear and start to accelerate it doesn't do it at all.

That's typically caused by a glazed surface on the flywheel and/or pressure plate. Could also be from oil on the surfaces that has burned into a sticky mess. Pull the trans, then the clutch and see what it needs. You pull the trans up thru the access in the floor of the cab (remove the seat and drain trans first).