Drain plug weeping fluid

[Nelly 186]

I have a small but annoying issue on one of the gearbox drain plugs.

Recently drained and refilled the gearbox, with new copper washers from SJ.  The plug nearest the front of the car has been fine but I have had a very small leak front he plug nearest the back of the car.

Have tried on three occasions to sort, even purchasing a wider copper washer than the SJ version but still not resolved.

Anyone had this or any tips on how to resolve?  Not sure if I should use some kind of sealant, or two washers (although with the compression I am not sure this would work?).

[LOTUSMAN33 1,470]

Neil

Heat the copper washer on the gas hob holding with a scriber or similar until glowing cherry red then quench in water, this will anneal the washer, it will seal fine then. 
I do this with all copper washers and not had a leak since, if the surface of the plug or housing is very rough then a little loctite 574 or similar car help provided the area is clean first.

Dave  

[whiskybob 9]

Interesting solution Dave.  I have the same issue caused by a slight irregularity to the plug housing. Will certainly try it.

Robert

[Nelly 186]

Thanks Dave, will be giving that a try too.

[ekwan 70]

At the worse case scenario, use an anaerobic thread sealant from Loctite. 

[Andyww 1,289]

Its possible the leak is appearing to come from the drain plug but actually isnt.

It could be from speedo drive, or joint between rear cover and rear housing or rear housing and main body.

[ekwan 70]

20 hours ago, Andyww said:

Its possible the leak is appearing to come from the drain plug but actually isnt.

It could be from speedo drive, or joint between rear cover and rear housing or rear housing and main body.

There should be oil traces above the drain plug. Clean up, start a career as Hercule Poirot.