1957 B31 inner gearbox cover

[Janacek]

Replacing kickstart ratchet pinion and quadrant and need to get inner cover off to replace the quadrant stop and re-seal the inner case.
Taken all the studs out and ratchet pinion,ratchet and spring and washer and spacer, but even after much tapping with a rubber mallet, the inner case is still solidly attached.
Am I missing something,or does the ratchet pinion bearing have to come out?or will it be necessary to remove the gearbox and get it on the bench to remove the inner cover.
Any advice welcome.

[JulianS]

Did you get this screw at the top?

[Janacek]

Did you get this screw at the top?
[/qu
ote

Did you get this screw at the top?

]
Yes,thanks Julian,I did.
Tried levering (gently)with a hammer shaft behind the clutch mounting and the top  moved a few thou,but I'm reluctant to give it much welly as I don't want to damage it.

[Janacek]

Having tried every trick I know,I can't get the inner gearbox cover off.Levering with a hammer shaft opens the top a fraction,but it is still firmly attached.
Will have to take the gearbox off and try again with it on the bench.

[DAVE BRADY]

Hi,

If I remember correctly these can be a bit of a pig to get off.  The studs seem to be a very good fit and so it needs to come off as square as possible.
Levering on the clutch cable adjuster may just be twisting it a bit.
Try using a piece of hard wood and get underneath to tap the case at the bottom and you may be able to get to the front a bit and do by the cable adjuster. Give a sharp tap rather than a whack eventually the sealant/ gasket should weaken - do each in turn.

Dave.

[Janacek]

Thanks Dave.Will try again tomorrow.I really don't want to have to take the gearbox off unless as a last resort.

[neil1964]

Just saw this thread (mentioned that screw in the other one!)
If you double nut the x4 long studs and remove them from the main housing that might help to wriggle the cover off?

[Janacek]

Already removed the studs,but still stuck.
If I fill the gearbox with petrol and light a match it might blow the inner cover off!
Second thoughts: perhaps not.

[neil1964]

Already removed the studs,but still stuck.
If I fill the gearbox with petrol and light a match it might blow the inner cover off!
Second thoughts: perhaps not.

🤣
Maybe just a more gentle 'heat spanner' with torch?

[Janacek]

Thanks for the heat suggestion Neil,but I am reluctant to use a naked flame with oil and petrol close by.However I will try boiling an electric kettle underneath and see if that helps.

[Dan_B33]

Hello, how about speedometer drive warm nut?
Have you removed it?
It can jam and you won't be able to remove the casing.

Dan

[Dan_B33]

If it's jammed. Go back with tightening the screws till the middle case goes bak to the position. You shall be able to rotate shafts freely

[Janacek]

The inner gear casing saga continues.
Boiled an electric kettle under the casing and using three lever points (clutch cable mounting, under timing case and between bottom lug and frame rail)
The casing does flex a few thou, and I can feel a little movement all around the joint,so the case itself is not stuck.There is also a little movement of the case around the speedometer drive,but non that I can feel around the mainshaft.I am guessing the mainshaft bearing centre is seized to the shaft.Given it a good dose of Plusgas and will try again tomorrow.If the case still won't come off,I will take the tank off and heat the centre of the mainshaft bearing with my little brazing torch.
Thanks everyone for your helpful suggestions.

[JulianS]

The easiest way to dismantle (and assemble) the box is to follow factory service sheet 311, which I have attached, rather than the Haynes method.

Basically remove the clutch and in ideal circumstances the inner cover complete with mainshaft is pulled from the box. If it is stuck try tapping the clutch end of the mainshaft with a hide or rubber mallet.

This leaves the layshaft and its pinions plus the sleeve gear the 2 mainshaft sliding pinions and the selectors in the main gearcase.