Pilot bushing, need to replace?

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matthon

matthon

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Swapping a 4 speed trans for a rebuilt one.
Old trans going into another car, flywheel, clutch, and all.
No issues with the old trans or clutch, it's been in use since 2012 when I rebuilt the shifter, installed a new flywheel/clutch/etc.

I measured both trans, length of input shaft, bearing retainer, and used a digital caliper to measure the input shafts at multiple points and with the caliper horizontal to the shafts.

I'm surprised how exact they are to each other. The old trans is in excellent shape as well as the clutch. Very little, if any, play in the input shaft.

I also put a new pilot bushing on both shafts, and although difficult to measure anything, on both it slides on/off with minimal space.

Iirc, it was an auto crank that was drilled by a machine shop, there is no roller bushing.

I don't see and could not find any metal shavings.

The pics are not that great, but a few with the flash on show what appears to be a pattern on the inside.

Is it ok to use the existing pilot bushing, or does it need to be replaced?

20190721_160738.jpg


Screenshot_20190722-221855.png
 
Pilot bushings can only be changed with the trany out of the way, so now would be the time.
On the other hand, if the clutch action was good, meaning that the tranny pilot shaft was working as it should, why mess with it.
So I think it is really your call,
But if everything was working fine and I knew the pilot bushing did not have a huge amount of miles on it, I would renew the lube in the pilot bushing pocket and leave the bushing alone
 
I'd feel it out with a spare input shaft to see that it doesn't have any burrs or gallling that would cause it to hang up or whatever, and if it's okay then not worry about removing it, putting a little fresh grease into it and putting a roller pilot in that fits into the converter register. No such thing as too much input support.
 
If you reuse it, make sure to lube hell out of it. I just "happen to know a guy......." LOL
 
I changed one once that had galled to the transmission input and then to the crank back and forth several times before galling into the crank for good. Grease, bread, modeling clay along with an old input shaft, followed by tapping it and trying to run a bolt into it, which pulled the threads every time, nothing worked. Finally had to cut a groove in it with a hacksaw blade and collapse into pieces with a chisel. Grease is definitely a good thing!
 
I read somewhere, probably on a forum, for new ones soak them in oil before installing.

I can certainly grease it.

Even if I had a puller for it, I think there is a certain type for that, I'd probably be hesitant to pull it out - if it ain't broke, stuff happens, you know.

Everything is in good shape, so I questioned it. I'll certainly take another look, or two, or ten.
 
Pulling those is a PITA. I used to have an expandable finger puller made by Proto. So yeh, I'm old.

Worked like this one here

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Don't forget you can also buy bushings/ bearings that fit into the converter bore, much easier to deal with. All the newer stuff "Magnums" use that style
 
And not only easier to deal with, a lot more robust design as well. I never cared much about hammering away at the old pilot bearing because the thrust bearing has a hard enough life as it is. The main reason I recommend greasing it and putting the magnum style in.
 
Man you guys have really beat yourself up replacing those pilot bushings...

Fill up that bushing with chassis grease. Find a wooden dowel that fits somewhat tight into the bushing. Hit the dowel with a hammer and watch the bushing fall out.

Your welcome.
 
Using grease & the method above for hydraulic pressure is a wonderful thing!
 
I guess I need to increase my wooden dowel collection to 1.

Worth a try for sure.

I watched some guy on youtube try it with bread just to see, I think it took a few hours.
Bread must not have hydraulic properties.
 
Bought a dowel that fit the new bushing, had a tiny bit of movement in the old bushing.

Put grease in, hit it lightly with hammer, pulled it out, suction of air kept it in, a little more grease, tapped the hammer, out like butter.

I don't have anything fancy to put the new one in with, so in the freezer it went.

Hoping that, some grease, the back side of a socket, and I'll be able to tap it in flush.

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