Pilot shaft bushing wearing fast and often!!

Input shaft bearing? Bearings between the back of the input shaft and the front of the mainshaft? Transmission to bell housing alignment? Bell housing to engine block alignment pins? How are you installing the bushings? If you hit them wrong they can be damaged. If this is a sintered brass bushing, then it is supposed to have something like engine oil soaked into it, probably the felt pad too. The only likely thing I can think of, is that you are getting new old stock bushings that have dried out in storage.

Earle

The YJ comes with a bearing instead of a bushing. The bearing can be made to fit, but the inside would need to be machined slightly to take the different tranny shaft diameter. Not a lot mind you, but it could be a bitch with a rat tail file....

The stock bushing uses 10W30 engine oil on a felt pad and should be soaked.

I think the OP is maybe running them dry by using gear lube and grease.

Mike

The way I understand it, sintered brass bushings are meant to be "impregnated" with oil, but as you say there should be no surplus.

Earle

Oilite type bearings in an auto engine? They worked reasonably well in low rpm computer gear where the side load wasn't very high and the rpm range was low. Excess oil was never good news.

Earle Horton proclaimed:

That's what was used in pilot bushings for as long as I can remember. Low duty cycle, heat, inaccessibility, and undesirability of excess lubricant were probably the main design factors. Maybe Volkswagen Bug was the first large scale production car to use a roller bearing type. First one I saw anyway.

Earle

They call it a 'bushing oil wick' in my book. This wick gets stuffed into the end of the crank, then the 'bronze' bushing gets pressed in. Once the tranny nose is inserted there isn't much room for oil to pass.

It isn't like you fill the end of the crank with oil or something....

Mike

"L.W.(Bill) Hughes III" wrote:

I've have searched high and low looking for a roller bearing for the rear of the crank. No company offers them that I can find so I took a bushing to an industrial bearing supply house and said find me a bearing to match these specs. We'll see what they come up with. The bushing is worn about .020" oversized and worn more on one side (off center). With all the oil and grease I've used over the last couple of bushing replacements, I have never had any clutch chatter. Perhaps the lube I've been using is too heavy. But I've owned standard transmission GTO's, Firebirds, Chevy Trucks, a Dodge Charger, etc., etc and pilot shaft bushings will last the life of the clutch or longer. I must have an alignment problem but I don't know where or how. The crank can't be bent or I would be pumping oil out the rear main seal. The input shaft has the recommended .005" in/out play in it and of course has lateral movement that I think would preclude an alignment problem with the input shaft. The block and bellhousing bolt up square and tight as does the transmission to the bellhousing. Next time it craps out, I'll stick in another bellhousing I have laying around. Thanks for the responses guys, Charles Ervin

The bushing fits into a sleeve that can be pulled out with a pilot puller tool. The shop we bought a new 'bearing' from for a YJ pulled it for us.

If you ask for one for an 89 or 90 YJ with the 258, you will get the bearing. This bearing only needs a couple hundredths taken off the inside to fit the nose shaft of the tranny. The YJ uses a tranny shaft with a different sized nose.

When installing a clutch, the 'plastic' jig tool to line up the YJ clutch plates will 'just' compress enough to use for a CJ clutch. There is that 'little' of a difference.

Mike