Gearbox Shims

[shand]

Having replaced a damaged spanish casing with an indian one I'm struggling to shim the gearbox, with a standard 2mm shim the gearbox locks up when the endplate is tightened down. The layshaft is fully home, the loose gears are fitted correctly. If I leave the shim out it stays free. Is it common to have to go undersize on these shims or have I done something wrong (that is common ) its the endplate that was supplied with the casing and the original spanish internals, if that makes a differance
Thanks in advance

[soulsurfer]

If we only needed one thickness then what's the point of the shim, various thickness shiims are available from MB

[10 inch Terror]

Hi mate, have you fitted the hub and torqued it down? by doing this you will pull the layshaft fully home which should then free the gearbox up. Try this first before you do anything else. Cheers Pete

[J1MS]

Fit the hub "as mentioned" and also fit the clutch sprocket and spider and tighten as the mainshaft can lock up when the endplate is tightened.
You should now be able to turn the spider if the gearbox and endplate have enonugh clearance.
If it's now turning when you have done this then retighten the endplate and check clearance on the shim.
Hope you sort it.

[shand]

Thanks for the replies, I fitted the shaft using a distance piece and the shaft appears to be hard up against the bearing, MB sell shims from 1.8 mm upwards and beedspeed sell half thickness shims, I've tried to measure the gap and it seems to be round about 1mm maybe smaller. I was just wondering if I'd missed something really obvious that was throwing me out or do you sometimes have to go that small on the shims

[jason frost]

Try another layshaft.

[RICSPEED]

check the gears dont sit above the shaft also

[shand]

Hopefully I've found the problem. I removed the layshaft and found a very thin complete o ring at the end of the shaft where the grooves start whether its been shaved of the new one or remains from the old one I don't know, either way I missed it twice going to have to start wearing my glasses. I'll try again when I get a new o ring and a hub nut
Thanks for your replies

[mark]

its shaved of the new one mate i use a slightly smaller o ring than you get with most kits . as long as when you fit it ,it sits prouder than the layshaft it will be ok.
are you using a casa bearing as i hear some are wrong size making shimming impossible

[shand]

Yes it is a casa bearing and it wasn't the o ring that was the problem