Classic cars forum & vehicle restoration.

[Miken]

Does anyone know of a company that can repair a worn spline on a gearbox mainshaft? The spline is of the usual parallel key type and the clutch plate slides on it (and wears it out).
The repair needs to be hardened.
Thanks
Mike

[ka]

I suppose there are two ways to sort this,
Machine a new shaft,
weld, then machine the splines onto the existing,
Either way will be an arm and leg. There are specialist 'one-off' engineers out there who have the knowledge, I am aware of an engineer who retired from his own business, makes gearbox gears for a hobby, so he has the equipment to do it, just how deep you will be into the Devil for your soul is another question.
I will keep an eye on this link, and if you are really struggling and no one else has a spare shaft, or inspiration, I will try to put the two of you together.
He is in Nottingham.
_________________
KA

Better three than four.

[ukdave2002]

Hi Mike

What vehicle is it for?

Dave

[Ashley]

Guest Gears if High Wycombe may be able to help or point you to someone who can.

[Miken]

Its for a 1933 Morris minor 4 speed non synchro box.
Its quite a complicated shaft so i don't think making a new one is practical.
It has a double helical gear an external spline an internal toothed gear/spline and an internal track for a needle bearing and would probably require the helical gear teeth to be ground after hobbing and hardening.
Unfortunately all the pre war Minors wear in this area. Plus there were 3 different types of g/box; 3 speed .4 speed non synchro and 4 speed synchro.
Im going to ask the welding rep at work about hard metal depostioin welding rods next time he comes in.

[ukdave2002]

I was thinking of metal spraying, I know of folk who have recovered cranks this way. Machining afterwards is difficult as the steel is harder, but if the part is that rare it may be worth it.

Dave

[Miken]

I have just signed up to a welding forum and 2 people have advised me that welding is probably not the best way to repair a shaft like this as it can affect the metallurgical properties of the shaft.
I have found a company who also recommend repair not by welding but by by metal spraying and grinding the splines back in afterwards .
http://www.davemacprops.com/DMPHOME.html
I sent a photo and was quoted £450 plus VAT.
I had better start saving.
Alternatively I wonder if a Morris Eight gearbox of similar vintage might be adapted to fit the car.

[Bitumen Boy]

Might it be possible to machine the splines on the shaft past the wear so it ends up a little undersize, and then adapt or find a clutch plate to fit the "new" splines? No idea if it's feasible, just thinking about it from a different angle.

[ukdave2002]

Have you tried posting this question on the Pre War Minor Network forum?

This problem must have come up before or someone may be able to help with parts.

Dave

Edit, just looked and you already have !

[ka]

i can recommend Dave Mac, I know him personally.
_________________
KA

Better three than four.