Gearbox - 3 syncro - Mainshaft Question

Hi there,

I don't know if anyone can help me...

I am currently rebuilding a 3 syncro with overdrive box and have found the mainshaft to be pitted and worn where the 18 roller bearings locate to the first motion shaft...

my question is can the mainshaft be repaired e.g. re-grind and some kind of sleeve fitted ?

and do you know any gearbox specialist (in the uk) which might be able to help ?

(As you can appreciate replacing the mainshaft is not an option, due to the overdrive mainshaft being quite rare and also shorter than the standard non-overdrive mainshaft.)

thanks

there is a welding process whereby the metal is sprayed to build it up
and it would have to be reground. probably heat treated also
might be costly talk to auto-machinists..

Looking at the diagram in Bentley, there may be several possibilities - grind it slightly undersize and use oversize needles, fit a sleeve, or metal-spray. A good machine shop should be able to handle it for you, and may be able to suggest more options.

Good luck!

Thanks for both answers! I will look in to getting it spay welded and see what they say :)

If rebuilding the shaft doesn't work out or is prohibitively expensive, you might want to talk to John Esposito at Quantum Mechanics in Ct. or Chris Betson at Octarine Services in the UK. They may be able to source a shaft in better condition.