Clutch Pilot Bushing

What is the proper clearance of the pilot bushing in the center of the flywheel, between it and the end of the pilot shaft of the transmission? Mine has swelled a little after installing it in the flywheel. I figure a few thousands would be enough for the pilot shaft to not wobble , but spin freely.

 

Welcome from Michigan, I wondered the same thing, someone here will know, I put mine together anyway and everything is good so far, that was 6k miles ago. Good Luck

 

Think about it like this. The only time there is a chance of wobble between pilot bushing and input shaft is when the engine is running and the clutch is pushed in. All the rest of the time the shaft is spinning with the engine. If the pilot hole is too big then the clutch disk will not center properly and can cause a vibration.

 

Measured the end of my Pilot shaft and it was right at 5/8". Cleaned bushing with a 5/8" reamer and test fitted flywheel and no slop and fit perfectly. Thanks for the responses!

 

Just for learning, does the input shaft move in and out (I don't think so) as you depress the clutch, or does the shaft just catch up to the speed of the crankshaft thus spinning same speed as pilot bushing, less any possible slippage?

 

I recall Mike (McRuff) saying 0.005" diameter in a previous post. If you search, you may find that post.

site:earlycj5.com pilot bushing clearance - Bing

There are other references online that say 0.002"-0.003".

 

A loose fit pilot bearing creates way more problems than just vibration. The potential misalignment of transmission input shaft will prematurely wear the needle bearings out in the mainshaft pilot. Sort of the same plot as a misaligned bellhousing. Obviously if the fit is too tight, the clutch will not disengage.