Scooterotica

Sorry for the bad pun, but has anyone run without the shim that sits under the lay shaft needle roller bearing?
What's it's purpose?
The reason my gearbox is locking is because the bearing is touching the end plate and removing the shim stops this.

The bearing should measure 20 x24 x 10mm wide so check yours. Are you sure the layshaft is fully into the bearing and hasn't rolled the o ring between the bearing?

The shim serves the same purpose as the one that sits on the fourth gear on the christmas tree.As the layshaft revolves the bearing revolves at a different speed,if it moves and touches the shim it makes the shim revolve at the same speed as it.The shim has a larger flatter surface than the bearing making it slide on a cushion of oil on top of the layshaft.

HxPaul wrote:The shim serves the same purpose as the one that sits on the fourth gear on the christmas tree.As the layshaft revolves the bearing revolves at a different speed,if it moves and touches the shim it makes the shim revolve at the same speed as it.The shim has a larger flatter surface than the bearing making it slide on a cushion of oil on top of the layshaft.

So no shim, less effective lubrication? Leading to the bearing coming apart?

wack 63 wrote:The bearing should measure 20 x24 x 10mm wide so check yours. Are you sure the layshaft is fully into the bearing and hasn't rolled the o ring between the bearing?

Ive pulled it through using a hub and hub locking tool. I'll check the bearing size but this is my second one where I have the same issue. One dropped on floor and lost a roller. The second broke some rollers when trying to turn layshaft whilst locked and I'd binned the previous one.

What kind of layshaft is it?

Is there more than one? Indian for a GP engine.

i had a similar thing a few weeks ago ?
I swapped the engine internal from one engine to another case, the donor case had been stripped of its original internals by myself a few months before.

But when i tightened the endplate up, the gear box locked up ?? so by a process of elimination , ie taking one thing out at a time, that could be causing it, and re fitting the endplate each time.
I eventually ended up with the total gearbox out .
The layshaft still locked up ???

I found that it was the layshaft endplate bearing track, that wasnt fully "home" in the endplate.
Took it off, knocked it further in , job done

Also worth checking its NOT a Casa rear hub bearing.
I have had problems with theirs being about a mm too deep inside the case, not allowing the layshaft to go in fully, makes shimming nigh on impossible.

Shaun.

Snails wrote:Is there more than one? Indian for a GP engine.

There's many. At least two types and possibly as many as half a dozen manufacturers. Any genuine ones should be ok, but there's some fake junk out there in fake SIL packaging.