Pilot Bearing vs. Pilot Bushing
 

Hoping some of you stick guys can weigh-in.

I've always run a stick in my GTOs - street and race. I have never had a fit problem with the brass pilot bushing...always stays in place. A much different experience with pilot bearing.

I had a '71 GTO about 20 years back and had to shim the bearing to get it to fit. Probably not a good idea but it was a street car. My race car at that time had a brass bushing and it was a good fit. Four years ago when I rebuilt that race 455 I pulled the brass pilot and installed a bearing. Last year when I pulled the tranny the bearing came off on the input shaft....didn't give it much thought. Last month when I rebuilt mt latest engine I pounded in the bearing. When I we took the engine off the dyno earlier this month again the bearing fell out - WTF?

3 different engines, three different cranks, three different bearings all the same results. The part number on the one that just fell out is 7109 - don't recall the manufacturer.

The listing appears to be correct - based on the guy at the parts store. Am I getting some Chebby bearing that they cross reference to a Pontiac? Anyone have a suggestion on the right bearing? Otherwise I'll just pound in a brass one and be done with it.

Sorry for the long post. Thanks for your help.

Dan

I would just stick with the brass bushing. Some people would say that a bearing would allow the input shaft to have some play and hurt the transmission. I never had any problems the bushing.

I have ALWAYS run the bronze bushing with a stick trans. Even if I had to modify the bushing to make it fit the crank/ input shaft properly which I have done when running a shield and block saver plate.

The bearing deal failed me shortly after I got the GTO in the early 60s and an oldtimer mechanic told me to put the bronze bushing in the thing and forget about it. He was right! Much more durable.

JMO

Tom V.

If the roller-bearing pilot bearing fails, it usually eats the pilot shaft. If the bushing wears out, it is sacrificed, not the pilot shaft. Enough said.

Jim

going by memory, the chevy bearing has a notably smaller OD then the poncho unit...

That is what a drill bit and lathe is for. LOL! I have made my own from bronze stock.

Tom V.

One common mistake is lubricating the inside of the bushing with grease. The bronze is sintered, so it's porous, and impregnated with oil. If the bearing surface is greased, the grease can get hard and block the pores, keeping the oil from lubricating the friction surfaces. It's recommended to do nothing other than dip the bushing in oil.

doesn't noxema help with clogged pores?

Yuk! YUK! YUK!

Tom V.

The bushing is more street friendly and forgiving under all kinds of weather and driving conditions.

The bearing is firmer for racing, alignment and critical higher rpm loads when shifting..... and when you can do regular clutch maintainance.

Go with the bushing especially if you`re drag racing and leaving with a 2 step.The bearing can`t take the abuse of having the crank spinning at 6k and the input shaft at 0 rpm.

I ended up spending $500 at Jerico because of that $7 dollar bearing.

I don't drag race but have used the bearing for the life of my car 30+ years. It's been changed out during engine rebuilds 3 times with 160,000 miles of total use with no problems.

Bushing for the win.

If my memory serves, your typical pilot bushing is made from graphite impregnated brass.
One reason they turn so nicely on the lathe. ;)

Quote:

"The bearing is firmer for racing, alignment and critical higher rpm loads when shifting..... and when you can do regular clutch maintainance."

Says who? You been playing with those Whimpy a##ed autos your whole life, LOL! Probably don't even know where third gear is on a manual trans.

Tom V.

Tom. I have raced in other forms besides stright line. LOl.

?????????????? All our circle track & road race engines run a bearing. Pilot bushings (being a softer material) can wear and also put a load on the input shaft bearing if the bellhousing alignment is off over a period of time.

Thanks for all the feedback. I appreciate the experience and insight.

Pilot bushing wear cause's trans input shaft main and needle bearing wear.

It also makes it very hard to shift - been there/done that.

I ran the same bearing in my car for many years. No problem. The fit/clearance is critical for small sealed bearings to survive. I do it at work all the time. It doesn't take much to compress the outer race and ruin the bearing.

Quote:

"Pilot bushings (being a softer material) can wear and also put a load on the input shaft bearing if the bellhousing alignment is off over a period of time."

If you set the bellhousing alignment up correctly in the first place with the proper pins, the bellhousing alignment should not change. The Bronze bushing should see minimal wear over the total surface area of the inner diameter. Course if your trans alignment was off in the first place and the input shaft was cocked, then a little extra friction on the bronze bushing vs the bearing will only make it worse for shifting.

I will still stick with a properly set up alignment and a bronze bushing. The
only input shaft transmission bearing failure I ever had was due a bearing type pilot bushing.

Tom V.