[HWYSTR455]

Originally Posted by Formula8

I did a clutch swap recently and found out the hard way there is a lot more to this than simply bolting everything in and calling it good. Although that is exactly what I did the first time. I simply had the flywheel machined and put in a Centerforce clutch. I threw it back together and I had to smash the clutch into the floor to get it to shift.

Turns out, the flywheel machining meant the pivot ball needed to be replaced with an adjustible pivot. The CF clutch I chose was .250 shorter than my earlier Ram clutch so I ended up using a McLoed adjustible height throwout bearing to make up the difference. I also used adjustible dowel pins to dial in my bellhousing to .001 (which took forever BTW) but my trans now goes in like butter and shifts like it too.

Not sure why turning a flywheel would require the use of an adjustable pivot ball, doubt you can take off enough material from the flywheel to matter. Curious as to how you came to that conclusion though. Most of the time when an adjustable pivot ball is needed is due to an aftermarket bell housing, motor plate, or some custom/multi-disc clutch.

In general, to determine if the throw out bearing is the correct length/size, when assembled, and at rest, the flat pad where the clutch rod goes on the fork, should be roughly at a 90 degree angle to the centerline of the trans, or maybe slightly forward. If it's way forward, the TO is too long, way rearward, the TO is too short.

That shorter pressure plate is roughly the difference between the 2 most common throw out bearing sizes, could probably have done the longer one and been good. The adjustable ones are not cheap, and usually folks recommend that one to avoid any call back. Basically, there's really only 3 different throw out bearings for GM cars. (see attached)

Remember, there's several adjustments for clutches, free-air (or air-gap) and free-play are different.

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