Gearbox drip

[Fender2004]

After changing the gearbox oil the sump nut has developed a leak
The leak isn't bad only one drip every couple of months or so. I was thinking of removing the drain plug and refitting it with some of that white thin tape that plumbers use to seal water joints. What do you think, or have you a better suggestion?

[Lancsbob]

Sounds a lot of work for 1 drip a month.
PTFE tape like you said or something like Loctight or Stag sealant.
I would try cleaning the area as best i could & smear sealant around drain plug
before i'de go draining gearbox for a drip a month tbh.

Bob

[Robert T]

Oh, how I dream of only one drip a month! At one point the Sprite was losing a litre of oil for every 50 miles driven! Spent ages chasing the leak, which turned out to be rear main oil seal - couldn't believe it when it was still leaking after fitting quite an expensive oil seal kit - it turned out that there was now a fracture of the pipe for the oil pressure gauge and somehow the oil managed to make its way down the side of the engine, along the top edge of the sump pan, around the corner and was dripping off the back of the engine, directly below the rear main oil seal!

Whilst PTFE tape might work, the leak is likely to come back again, and if you use two much, you might damage the threads on the sump. You could try thread-locking compound, which will fill any gaps in the thread and will not force the threads like the tape would, however I'm not sure whether oil would prevent it setting properly.

From reading other threads on here, I believe the Z3 sump plug is a bit on the delicate side and it is possible that it has been damaged by someone overtightening at some point. The best solution is probably to replace the plug with a new one.

Cheers R.

[Southernboy]

As RT has suggested - a new plug. But first inspect the plug and sump threads to determine which threads are worn or damaged. If it's the plug replace the plug, if it's the sump, I would suggest taking the car to an engineering shop to have a larger thread tapped into the sump and fitting a larger plug. The OEM size is M12. It would require going up to an M14.

[pingu]

DO NOT be tempted to tighten it. It is a tapered plug and you will crack the casing. Annoying, though it is, I have the same and have decided to leave it as one drop is insignificant compared to the amount of oil in the box.

[kkkrisss]

did you change the washer?

[Lancsbob]

did you change the washer?

I think thats the engine sump not gearbox unless their the same.

[Fender2004]

Many thanks for all of the advice. I'll have a bit think before doing anything.

[Fender2004]

did you change the washer?

I think thats the engine sump not gearbox unless their the same.

I'm sure that there was no washer on the gearbox sump nut.

[kkkrisss]

Usually drain plugs have washers. Could not remember about the gearbox drain plug but it is possible it does not have one.

[pingu]

It's a tapered plug. It doesn't have a washer.