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Judging gearbox bearing play

Posted: Wed Apr 29, 2020 1:57 pm
by Michiel
Dear all,

Yes, my first post on this forum although I did a lot of reading. A year ago I fulfilled a long time wish for a 2-door 'project'. It was owned by a schoolteacher most of its life, has done 57k miles since 1967 and is totally original. But needed a LOT of welding which kept me busy for 6 months. I'm now checking the ribbed case gearbox and would like to ask your opinion on this.
The input shaft first motion can be wiggled 1mm (40 thou). The play must be the bronze bush in which the 3rd motion shaft turns, not its ball bearing?
The rear end of output 3rd motion shaft can be wiggled 0.5mm (20 thou). That must be its ball bearing.
Should I use the 'box as it is?

Many thanks for you help.

Michiel
Schagen
Holland

Re: Judging gearbox bearing play

Posted: Wed Apr 29, 2020 2:10 pm
by philthehill
The first motion shaft can be wiggled as you describe even when new. The front of the first motion shaft is supported by the bush in the rear of the crankshaft so when assembled there will be no play.

The third motion shaft can be wiggled as you describe even when new. The rear of the third motion shaft fits inside the front of the propshaft and is supported by the propshaft which turns inside a bush fitted in the gearbox tail housing so when assembled there will be no play.

Do not stand the gearbox upright on its bell housing end as any crud in the gearbox will drain to the first motion shaft gearbox bearing and could cause damage.

I would recommend that you have little to worry about. Fit the gearbox and enjoy.

Phil

Re: Judging gearbox bearing play

Posted: Wed Apr 29, 2020 2:23 pm
by Michiel
I'll follow your advise. Thanks for your reply Phil.

Re: Judging gearbox bearing play

Posted: Wed Apr 29, 2020 3:32 pm
by paul 300358
I have just rebuilt a ribbed gearbox with new original bearings ready to fit to the car when things get back to normal, it's got the same play.

Re: Judging gearbox bearing play

Posted: Wed Apr 29, 2020 4:47 pm
by Michiel
So mine is as good as new 😀 Thanks Paul..