why do people recommend pilot bushing vs. pilot bearing?
 

I was surprised to see everyone recommend I use a bronze, fluted pilot bushing vs. a pilot bearing.

Pilot bearing typically used on heavy duty applications.

Anyone know why pilot bushing everyone here recommends the pilot bushing (vs. pilot bearing?)

I'm just guessing but I think the size of the input shaft would make a difference. The smaller the shaft you would need to go with bronze or brass. Very small needle bearings IMHO would not hold up very well. Anyone?

:iagree: I have had 3 pilot bearing failures, I have gone back to pilot bushings.

Pilot bearings hold up well if the input shaft is perfectly aligned with the crankshaft and will provide less friction between the input shaft and the crankshaft resulting in a cleaner, quicker clutch release. Unfortunately, not all bellhousings are perfect and a slight runout or misalignment between the tranny and motor can toast a bearing. The bushing is more forgiving in this regard.

what typically happens during a pilot bearing failure?

Squealing when you put the clutch in? (this is just a guess).

Ive been using pilot bearings and have never had any issues.

This is a good answer that makes a lot of sense.

Knowing that I havent had issues with pilot bearings, Im tempted to again use a pilot bearing.

Clutch chatter. Upon inspection all the needles are missing. I beat (6000 RPM drag stip launches with a lightweight flywheel) my clutch hard and it appears to me that the pilot bearings cannot take the abuse.

I've used pilot bearings without any issues...and yes it would seem to me that a bearing is more technically advanced than a bushing...but what I have read about is not the $20 bearing failure per se, but when the bearing fails, it can tear up your transmission input shaft which could be a much bigger problem.

I know (from reading your posts) that you are a very techincally savvy person, but could there be 'chance' that your transmission / bellhousing are not aligned perfectly - or that the pilot bearing went in slightly off-axis?

I drive my car hard too (though no 6000 rpm drop-clutch launches).

Im trying to figure out why your/my experience is different.

You can hold & fit a pilot "bushing" in your hand and pretty much visibly determine it's quality. You don't want anything that's iron sintered just impregnated bronze. Fluted or not it would I believe be the preferred!

In this "pilot bearing" you've got the needles, the seal and the cage that holds the needles that can fail and lubrication is what's there. When any of these fail it takes out the other and without doubt will generally ruin an input shaft. Now you need to take into consideration who assembled your torrington pilot bearing - is it yet another Chinese sourced product?

A ball/roller bearing that's used for Pontiac, Buick, Olds and others including the larger diameters that are flywheel inserts vs crankshaft inserts are a different conversation entirely.

http://lh3.ggpht.com/_Fx4nqL8K_5o/TT...0/DSCN1439.JPG

New territory for me with pilots but is there a recommended premium pilot bearing available? So far not a lot of love for the bearing but for a street only car, is a bushing preferable?

I've used bearings in the past with no problem, but I used a dial indicator to index the bellhousing and offset bellhousing pegs to make sure I had zero runout. If tolerances are within specs, a bearing will have less drag on the input shaft and shifting will be easier and quicker. The synchros won't have to work as hard.

Offset dowels don't catch much discussion these days. It's been quite sometime since I've heard them mentioned. They would be "new territory" for many here. It was very common to use these for nearly every MT bellhousing/shield install. Some are quite expensive!

We had the dowels available but there weren't bearings for the SBC "THEN" only for the Buick, Olds & Pontiac. A couple Pontiac/Olds guys actually used a pilot bearing that required the bore in the crankshaft be extended a little deeper and it allowed full support for the machined nose of the input shaft.

Thanks for the positive comment. To answer your question yes I did indicate my bellhousing and it was aligned within the required spec. That was at least 10 years ago and I forgot what that spec was. Over the next 5 years I destroyed 3 pilot bearings and eventually replaced the bearing with a bushing and it has been fine ever since. Maybe I was using a cheap pilot bearing and it would have been fine with a quality bearing? I use my clutch hard and I made the assumption that the bearing cannot take the pounding of 6000 RPM launches and eventually fails. In the last 10 years I have probably made at least 1000 1/4 mile passes, countless laps at Road America and 100,000 plus street miles.

I have had good luck with the bushing and I guess I am not to interested in trying a bearing again.