Taller 5th in a 33/11

[ME 109]

All bearings replaced. A little perseverance and the bearing is off the input shaft and new one in place. Note to self: don't forget to replace clutch actuating rod oil seal.

The front input shaft bearing came out very easily and the new bearing went in just as easily with a little heating of the casing.

The fun has just begun tho'

[spartanman]

Originally Posted by Wirespokes

I've seen that sort of wear when the front output shaft bearing has gone, and the gears don't mesh properly, along with grinding all the swarf floating around in there. It might not hurt to re-use the gear, I don't know. But if another better one was available, I'd certainly change it out!

It's actually best to use fifth as an over-drive and not put much stress on it because of that front output bearing.

I would absolutely replace the gear. Gears are case-hardended and have a relatively soft core. Damage accelerates once you wear though the hard surface layer, which that gear has.

[ME 109]

Ready to set the shafts axial play. Now's the time for accuracy in measuring and interpreting.

I don't recall any shims under the bearings at the front of the tranny........are they always all under the cover plate?

Anyone use a sealer as well as the gasket for the rear cover?

[supershaft]

Don't forget to put the oiling plates under the front bearings.

The measurng is a bit of a guess with the bearings rocking and whatnot. I measure from the inside race.

I don't use a gasket. Never had an issue for it and it takes a variable out of shimming. I think they work best on the tight side. I leave the input shaft seal out until I shim them. It's easier to tell what is going on with your shim job that way for the seal sometimes dragging a little.

[ME 109]

I have the baffles under the front bearings.
That's a good point about leaving the input seal out.
Are the inner and outer races that close, so as to be able to take the shim measurement from the centre? I understand why measuring from the centre would be more accurate tho'

I have a donor cover plate to use for measuring the shims however I'm measuring some differences in depth. I've measured three or four places around each hole and have found differences of perhaps ten thou.
I'll need to re-asses and see if it is bearing movement that is giving me the differences, or cover plate thickness.

I've measured my tranny cover plate and the individual pockets (when measured in three different places) are within one thou. All good there.

If I don't use a gasket, would the Three Bond silicone that I use for barrel bases be suitable?

[mark1305]

Originally Posted by ME 109

I have the baffles under the front bearings.
That's a good point about leaving the input seal out.
Are the inner and outer races that close, so as to be able to take the shim measurement from the centre? I understand why measuring from the centre would be more accurate tho'

I have a donor cover plate to use for measuring the shims however I'm measuring some differences in depth. I've measured three or four places around each hole and have found differences of perhaps ten thou.
I'll need to re-asses and see if it is bearing movement that is giving me the differences, or cover plate thickness.

I've measured my tranny cover plate and the individual pockets (when measured in three different places) are within one thou. All good there.

If I don't use a gasket, would the Three Bond silicone that I use for barrel bases be suitable?

When I had to rebuild a Ducati 900 engine after Ducati quit using the paper gasket between crankcase halves, the thickness factor decreased from somehting like a .015" gasket crushed to .011" to NIL with the Threebond (or 1194 or the equivlant). I found that to be fairly accurate when I had to split and redo the crankcase a couple of times for various other reasons.

So for that kind of sealant applied properly (thin), I would use NIL as the thickness calculation.

[WacoDirtryder]

I put the taller 5th and lower 1st in the GS i rebuilt and it sure is sweet it might be only 3 or 4 hundred rpm but we are not talking jap bike with a 13k redline it makes a huge difference i think.

[ME 109]

Originally Posted by WacoDirtryder

I put the taller 5th and lower 1st in the GS i rebuilt and it sure is sweet it might be only 3 or 4 hundred rpm but we are not talking jap bike with a 13k redline it makes a huge difference i think.

3 or 4 hundred rpm reduction will be sweet when hauling the mail I reckon.
I've always thought that 4-5 was close ratio, so the wider ratio should work well.
Just gotta get this shimming plate business sorted. I'm searching for one in Australia to buy......
Anyone in Aus know a supplier?

[disston]

I thought you said you have a junk rear cover? The idea is to machine a rear cover so it is flat on both sides and taking the outer edge off turns the bearing pockets into bearing holes. If this is done carefully enough I think you end up with a shimming plate tool. Add to this a couple of parallels and you are set.

So all you need is a junk rear cover and I think you have machinist there?

[ME 109]

Thanks disston, I do have a loaner cover plate that has been machined, it is on my tranny at the moment.
Trouble is, I'm measuring different depths on the input shaft bearing, meaning the cover isn't machined parallel?
The cover thickness has been measured at a given point at each bearing hole, and the precise positioning for the depth gauge is marked.

It may be as simple as taking my measurements from the 3 marked positions on the cover plate.

I'm just concerned with obtaining the precise measurements required.

I'm waiting to speak to the chap who kindly loaned me all the tools to fix my tranny.

[disston]

Oh, when I did this I used the baking it in the oven to harden the epoxy method. Don't like that method anymore. I will measure the next time.

I think maybe you take the measurement three times at each hole and average the results?

[ME 109]

Originally Posted by disston

I think maybe you take the measurement three times at each hole and average the results?

Good theory, but I measure over ten thou difference on one of the holes.

[ME 109]

No luck finding a shim measuring plate in Aus, not Munich or Moto Hansa. Not even Motobins that I can see.
I must be some sort of pioneer.

[supershaft]

Yea, the cover plate's bearing bosses vary in depth around the boss. I just roughly average my findings. Like I said, it's a bhit of a guessing game no matter what.

[Big Bamboo]

Originally Posted by ME 109

No luck finding a shim measuring plate in Aus, not Munich or Moto Hansa. Not even Motobins that I can see.
I must be some sort of pioneer.

Cycleworks has them: http://www.cycleworks.net/index.php?...products_id=39