Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Changing Rear Axle Oil

I've had a weap of oil from the rear axle so I decided to do an oil change & try to stop the leak. Since changing, the leak has got worse from around the drain plug.

The drain plug screws directly into the casing and does not have a sealing flange to form a seal against the casing as a typical engine sump drain would have. The seal must be made by the screw threads.

Can anyone help please with advice how to get a good seal. The only article I've found on the net suggests PTFE tape.

The Mogs a 1978 4/4

thanks

Mike

On the shop floor (many years ago)we used to apply a small amount of Red Hermatite to the threads of the drain and level plugs. I am sure Hylomar or any other brand would work as well.

Hermatite was what I used on my motobikes & never had an issue.

Before any adhesives are used - and I'd be trying very hard to avoid this, make sure the threads on the drain plug are clear and so are the ones on the axle.

Given the age of the car, the axle should be a Salisbury 7HA. Salisbury axle threads on the plugs are BSTP (ie taper) so a plug that fits and is screwed home is unlikely to leak. Not unknown for these to have leaks, but often, the leak is actually on the pinion seal and the leaked EP90 then runs down to the lowest point - which is the drain plug.

Another area of leaks on this axle occurs when the inspection plate bolts are not fully tight. Again the oil runs down and drips off the drain plug. Have a gentle lean on the bolts with a good spanner (many socket sets have handles that invite overtightening).

So be careful you are not trying to fix a non existent fault. A leaky pinion seal I'd live with unless it was terrible.

Lastly, EP oils spread very easily and a small leak can look a lot worse than it really is. Plus the fact it leaks - you know there is oil in there. The time to worry is when it stops.