1951 A7 oil seal

[Rex]

A quickie-
1) the oil seal behind the clutch in the primary chaincase, is it a generally available common or garden oil seal? I haven't drilled out the rivets yet to see.

[morris]

SKF CR 20x37x7 are ok
Should be readily available in any bearing shop

[Greybeard]

A quickie-
1) the oil seal behind the clutch in the primary chaincase, is it a generally available common or garden oil seal? I haven't drilled out the rivets yet to see.

Be careful working on those rivets; the metal is thin and the holes are close to the edge. I used tiny nuts and bolts instead of rivets but had to thin the heads so they didn't foul the gearbox sprocket.


Are you sure that seal is leaking? If you use ATF in the primary you can tell if it's coming from there. The primary case should have only enough oil to wet the chain. Other sources of oil in that area are gearbox output seal and engine breather pipe.

[Rex]

I don't yet know if it'll leak or not GB as the engine is dismantled, but visually the seal is shot and needs replacing. I was afraid those rivets (or the size of them) was going to be problematic, so thanks for the warning.

[Greybeard]

You might try blind Pop rivets but put them in from the back of the case so they don't protrude too far.

[Greybeard]

Just had a thought: I may be mis-remembering the problem with the bolts or rivets. It may be the clutch case that was rubbing on the nut heads rather than the gearbox sprocket which really cannot be that close to the case. Sorry to confuse you but just be aware that there is not much room for anything larger than a small rivet.

[morris]

To get rid of the rivets I made a ring of about 3,5 mm thick to go at the back of the primary. I drilled and tapped 3 corresponding holes 4BA size. I reused the front ring, made the screw holes taper and clamped it all together with three taper head 4BA screws

[Rex]

That sounds like the way to go. Thanks.

[a10 gf]

Used screws and nuts, secured with some loctite, working perfect.