Morris Minor Owners Club

maybe the leak is from the sump gasket at the rear

The plate was fitted to the Marina/Ital sump to help steady the Marina/Ital gearbox against the Marina/Ital engine.
To overcome any leaks you can silver solder or braze around the plate to seal any leaks.
The plate is not required when fitting the Marina/Ital engine to a Minor/Midget gearbox and if required can be carefully removed or at least cut back.
Another problem I have experienced is the rear lip of the rear sump gasket groove becoming detached from the sump proper and allowing oil to leak past the rear sump seal.

Thanks for the comments and guidance. Oil leaks all the time when standing, which to me indicates it is more likely to be the plate which is below the oil level, not the sump gasket.
Phil, the car has a five speed box, with minor clutch linkage. The reverse gear selection is push down, and forward top left. I'm not definitely sure which box it is.
Looks like sump off, a good degreasing and clean, and then probably silver solder all round.

No doubt you have the BMC 'A' Series to Ford gearbox adapter bell housing which is the same as the BMC 'A' series Minor/Midget gearbox but without the gearbox so the same will apply in that the plate is surplus to requirements.
If you are very careful you can grind out the spot welds holding the plate on without grinding into the sump. With the plate then removed you will be able to see what the problem is and rectify as appropriate.
Phil

Thanks Phil.

I would remove the plate and weld (or braze) whatever is causing the problem. Silver soldering 'all round' sounds like a 'sticking plaster' job to me...

As the plate does not do anything but sit there in a Minor application silver solder will be more than adequate to seal any weeping of oil.

Booked into have sump removed and leakage area inspected from the inside. The guy is a specialist welder/restorer, and subject to the inspection, he will either repair from inside with plate left in situ, or will remove the plate and plug weld any suspect spot weld areas, then make good externally.

Sump gasket has been ordered from the MGOC, which has cork side gaskets, but modified front and rear rubber end seals instead of the original cork. Supposed to be far better at stopping oil leaks in MG Midgets with the 1275 engine.
Does anyone know whether these rubber seals have been fitted to, or would fit, a 1098?

Too big for a 1098 which has smaller mains (unless you have the Rare CC engine of course). I dare say they can be cut down - but really no need - the cork seals work perfectly well.

Yes they can and according to my experience should be used. You have to trim them slightly to fit on the 1098cc sump with a hacksaw and file, as there is a metal reinforcing ring inside. They work very well and they are on my car for eight years now and not a drop of oil to be seen. I could never get a decent seal with the old cork seals although some of the modern cork seals are actually rubberized cork.

Regards
Declan

My cork seals have been on for ~19 years and nary a drop of oil!

Ay, but that's probably good quality distillery grade Scottish cork
Regards
Declan