65tripleblack

See post #9.

Muncie and Richmond trans have a lot of slop in the input shaft which makes bellhousing alignment somewhat more forgiving. Later trans like the TKO, T45 and T56 do not. These will destroy a pilot bearing in short order and will quickly wear out a bushing if the bellhousing is not within their specified runout dimensions.

An added benefit of concentricity is ease of shifting, especially at higher RPM's.

GM issued bellhousings are notorious for "marginal" and excessive runout as relates to use of a modern transmission. Not surprising, as everything from GM, back in the "good old days" had huge tolerances and very poor quality control.

Frankie the Fink

That is a required step before doing the Keisler Tremec conversion !!
Fortunately my '61 did not require any offset dowels, etc.. and was well within specs..

Dave64

My Tremec 600 didn't come with a needle bearing bushing. It came with an aftermarket-looking, silverish-colored bushing, which I chucked for a good bronze bushing from GM.

Dave

44Lawrence

pilot bearing or bushing. My change over from auto to TKO 600 manual about 8 years, 10k miles ago in my 91 12cyl Jaguar (please no jokes) came with the pilot bearing in the kit from Driven Man. I didn't dial in the bellhousing center line, should have but didn't. Fast forward to last year, needed throwout bearing work. Long story short, very lucky I guess. The pilot bearing looked new, repacked it put it back together.
Lawrence

ejboyd5

I could never understand why anyone would install something with multiple moving parts, i.e., failure points, when there is a perfectly good one-piece alternative.

GTOguy

Have been running BALL bearing pilot bearings for the past 40 years in all my 4 speed GTO's with no issues and for 100's of thousands of miles, with a lot of abuse. Pontiac specifies a ball bearing, and NOT a bronze bushing. That said, bearings can dry out and fail, and when they do, their hardened parts can wreak havoc on other components. Bushings are 'cruder', but are pretty bulletproof. Have no idea what's in my '61 'vette.

44Lawrence

I look at it this way. I got 10yrs to date, still looks new, no noise, vibrations etc. I was not about to "fix something that wasn't broke" or play with fitting a bronze bushing, "been there done that". So, is there an advantage pilot bearing over bronze bushing? I surely don't know. I never had either fail, but this is my first time with a pilot bearing .
Lawrence

DUB

I prefer the NON MAGNETIC bronze bushings myself. I have several bronze bushings from clutch kits that a magnet will stick to and i can not bring myself to use them...and purchased the original design which is NON magnetic.

I have also used the roller bearing design on 6-speeds I have done and the Tremec transmission that they required to be used. And when I took out the roller bearing on the 6 speeds I have done it was fine and it was being replaced because the clutch needed to be replaced....and these cars were HIGH miles...50K + miles.

I myself have wondered WHY the design change on this pilot bushing bearing area and someone told me that the roller bearing was more precise. I do not know if I 'buy' that explanation.

I do check the bore concentricity...and correct it if needed.

And I can say that when installing the pilot 'whatever you choose'...I am careful not to damage it in any way so the input shaft does not stick or bind on it...which can cause for problems in the clutch engaging when the engine is running.

I am going to hopefully re-work a press I have made that bolts to the crank shaft and allows me to press the bushing in. It works but it is really crude an the next time I do a clutch and I have the time to do a bit more R & D...I plan on trying to get it 'better'. Right now it takes a lot longer to set it up my tool than tap one in....but it something that i just kinda want to do.

DUB

jdk971

what would happen if you use a metallic pilot bushing? thanks jim

Powershift

Accelerated wear on the transmission input shaft nosepiece. See pics about halfway down the page. http://www.crankshaftcoalition.com/w...g_and_bushings

Larry

wmf62

I've never heard of a ball pilot bearing..
Bill

Powershift

Most have needle bearings............but a Google search does show a few ball bearing pilot bearings that are out there in cars.

Larry

71scgc

Who or where is a good source for the bronze or oilite pilot bushings?

I did a TKO 600 conversion on my '71, and used the supplied pilot bearing. I was skeptical...

I don't have many miles on the setup (< 1000mi). It will be coming out soon for a engine change and I would like to use a proper bushing in the new engine, rather than the bearing, and will dial out the Quick Time bell as well.

Carter

DZAUTO

I believe some Olds engines used a BALL BEARING pilot bearing. AND, with that said, MANY Olds engines (such as later 455 cranks) are NOT machined for a pilot bushing/bearing because MOST Oldsmobile cars came with an auto tranny (puke, puke, puke), thus, no need for the crank to be machined for a pilot bearing/bushing. When I sent the 455 for the Cutlass to the machine shop, I did not know this. Purely by accident it was mentioned to me that there was no pocket in the end of the crank for a pilot bushing. So I had the machine shop cut the pocket and install a bushing that I furnished. This was back in 1988, and I have had ZERO issues with a bronze bushing in the 455 with a Richmond Street 5sp.

Vet65te

Just about all of my project cars have been Chevys and never ran across a factory ball type pilot bearing until I was reassembling my '64 GTO. It kinda looks like a small ball type axle bearing. Since the GTO was put together around 2002, I've only put a couple thousand miles on it and no problems. After the disintegration of the GM needle pilot bearing in my 66 L79, I won't be using that style anymore in the Chevys.
Mike T - Prescott AZ

59 navy

I don't mean to crash this thread but I have a question. I replaced the bronze pilot bushing in my 59 but could not get it far enough in to be flush. It is out by 1/4 of an inch. I was told the tranny would hold it in place. Is this going to be a problem? 59 navy

GTOguy

Navy, it needs to be all the way in. The trans is not supposed to hold it in place....if it is, the mainshaft shoulder is jammed up against the protruding bushing, causing unwanted pre-load on the trans. Whether bearing or bushing, I always place it in the freezer for an hour or so so that it taps right in easily. Works like a charm.

Stingxray

I ignored Keisler warranty requirement for the Roller pilot on my SS700 Trans. I "DID" however dial in the scatter shield run out to +/- 0.003 . Great product below
http://www.robbmcperformance.com/products/dowels.html


Napa # for the Bronze Pilot Bushing. BK 6151161
and O'Reilly store under the Federal Mogul # PB-656-HD.
Be Sure to take a magnet with you and verify it's Non Magnetic.( No Iron )
Please Note: the pilot Bearing/ Bushing only come into play when the clutch is disengaged, pushed in.

4 Speed Dave

In my Nova with a G-Force G101 transmission the input shaft splines are cut back farther which allows the use of a large ball bearing type to be used. NOTE: You can't use this on regular Muncie or ST-10 transmissions. So there are applications where a ball bearing style is used. The bearing has a collar that presses into the back of the crank in the space where a torque conv snout would normally go.

Powershift

That information is in the archives, and I think was also a recent thread here. So check past threads. Here it is: https://www.corvetteforum.com/forums...t-bushing.html

GM still sells one, although it is a bit different than the 1950-60 originals. Also contact Autogear, who participates here on this C2 forum. They say they have them for sale. Probably better than the new GM ones.

Larry