Morris Minor Owners Club

I have a small leak of oil coming from my 1967 Moggie gearbox. It drips at a rate of about 1 drip a day, however the areas around the gearbox & crossmember are covered in oil. I've only had the car a couple of months, so I'm not sure whether the splashed oil was left from some previous mechanical work. I plan to remove the tunnel from inside the car & clean up all the grease & try & reveal the location of the leak.

I have 2 questions:

1/ Can anyone suggest a good degreaser for a job like this?
2/ Has anyone tried using one of the many oil leak stoppers that work on the principle of "Regenerating the seals" in manual gearboxes?

I am unlikely to try a leak stopper unless replacing the faulty seal is prohibitively expensive.

Any constructive advice would be appreciated.

Hi is the oil coming from the gearbox drain plug or the hole and pin hole in the bottom of the bell housing may not be the gear box could be rear crankshaft or the sump a thorough degrease and check..

The mechanic who did the MOT said it was from the gearbox, but there was too much oil around for himto pinpoint the leak, hence his suggestion I clean it all up.

I used Gunk Green de-greasant. It worked for me and is supposed to be biodegradeable. See here: https://www.halfords.com/motoring/engin ... 32053.html
If things are really oily, it may take a couple of attempts to get rid of all of it.

Thanks for that!

In my experience, Jizer is a far superior degreaser. The gearbox as standard does not use a normal seal and would not benefit from a leak stopper.

Your most likely source of leak is the rear engine crank seal that can appear as a drip from the bell housing.

The rear G/Box seal is a standard seal with a felt backup

simmitc wrote: ↑Sun Sep 18, 2022 4:34 pm In my experience, Jizer is a far superior degreaser. The gearbox as standard does not use a normal seal and would not benefit from a leak stopper.

Your most likely source of leak is the rear engine crank seal that can appear as a drip from the bell housing.

Probably why the mechanic told me to wash off ALL the oil in the area in order to reveal the leak.I've never heard of "Jizer".

serowman wrote: ↑Sun Sep 18, 2022 9:33 pm The rear G/Box seal is a standard seal with a felt backup

I understand that leak stoppers cause rubber seals to "Regenerate", so presumably they wouldn't work on a felt backed seal. What would be involved to replace the seals around the gearbox?

The felt seal is not regenerative.
There is only one lip seal fitted to a standard Minor gearbox and that is on the rear output shaft. All the rest are gaskets.
The gaskets can be easily replaced. The front gearbox cover gasket cannot be replaced without taking the gearbox out.
If you have a 1098cc ribbed gearbox fitted it would be of benefit to fit a front cover with lip seal.
https://www.morrisminorspares.com/gearb ... ew-p830914

Thanks.