Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Mainshaft High Gear Bushing

This transmission is a four speed which was in parts when I got it. So just started cleaning up parts and assessing the condition. So far this has been the only problem. The High Gear Bushing was sticking out the gear end about 1/4 inch. I set up to press it back in with the vise. Had to crank the tension on the vise way up to get it to move. When it finally moved it went with a "pop", and after about 4 or 5 pops it was seated. There is a small amount of play when installed on the shaft - just enough to feel. That slight wear is only detectable on the gear end, while the sprocket end has no detectable wear.
Do you think it will stay put and is the wear acceptable?

Should be fine

The "pop" is the press fit of the bushing seating on the gear - normal and it shouldn't back out...

Clearance is about .003" - .004" I believe

Was there two bushes in there or one long one? Off hand I only remember the two bush version where the bush extended out the end of the shaft and through the door seal. The wear mark on the nose of the shaft suggests the door seal runs on the gear, not the bush.
If you heated the gear then sprayed the bush internally with Freeze-it the bush would have gone in easier.
It could not have been run like that so I do not think you are seeing wear on the end. Maybe something the PO did to push the bush into place.
The gear runs in a ball bearing so unlikely the bush will move.

The equivalent bush in a Commando has been known to migrate, and gets ground away by the next gear on the mainshaft.
I believe they have 2 separate bushes.

I think Triumphs just have one long bush, on pre-units it projects through the inner chaincase sliding seal.
I think you're right that in the units the seal runs on the gear.

When I look closely at the 1st pic, the bush looks far from new, I can only suppose that PO began removing it and then gave up.
God only knows the story. Perhaps he thought it was worn.
I don't think it is possible for the bush to migrate in a living gearbox to that length, so its something that's happened through attempted maontenance.

You've pressed it back in successfuly. Doing that on a long, slender bush like this tends to squash it up a little (both OD and ID) so it should stay where it is, as long as the shaft still goes through freely.

Very good, thanks for the replies! Yep, it is one long bushing, the seal runs on the gear, and probably owner attemted to change. I did heat the gear lightly before pressing, but didn't think of chilling the bushing.
Thanks again.
I may have more questions later. It's very difficult to assemble an engine unit from boxes of parts.