Attention all gearbox builders

Have you replaced the bushes ? Are they too long ? The shoulder on the spindles should stand slightly high.

Previously George Phillips wrote:

Last post disappeared into the ether! Thanks Richard. Yes, Idid renew the bushes. They are the correct ones. I think I'll take the bolts out, apply some threadlok and retighten sufficiently that the camplate and quadrant move freely. The spring washer and threadlok should hold it all safely? Wonder what they did back in the 50's? George

If these bolts were tight when you stripped the gearbox but you can't tighten them now would suggest that the bushes are slightly too long or not fitted into the casing fully. Just because the bushes are the "correct ones" doesn't automatically mean that they are right! I've been caught out on that a few times.

I would strongly advise that you sort it out correctly now. You have already spent a lot of time and effort rebuilding the box and I feel that by using spring washers and Loctite you are only asking for it to come back and bite you in the backside at a later date.

Colin

I agree. The shoulders on the spindles should be slightly longer than the bushes so that when the bolts are fully tightened against the washers there is slight end float.

The bushes should be flush on the outside and proud inside the box if fully home. It sounds as if they're too long. Do you still have the old bushes to compare ?

Hi, I rebuilt a commando box last year, and found it all fitted OK. I have a Matchless box I thought would do my new N15 cs, but now you have me concerned that a spares kit will not fit. Have you remembered the tiny O rings each side of the Quadrant shaft? When I started fitting, it was usual to Stake the threads on moving parts because of production tolerances. When I built big Printing Presses bearings were scraped and shimmed. Machine tolerances before CNC lathes were pretty big. Precision is costly on old machines. I had a picture taken inside BSA's factory before ww1 and when they closed. Nothing changed, still the same old belt driven machines, fit only for scrap and worn out after ww2. Every factory in GB was the same in the fifties, so selective assembly or pot-luck. I made good money re-tooling Rover before they closed, unbelievable how badly alighned some tooling was when new.