gearbox leak help required

[xillent]

Chaps,

My mate who's also a member asked me to post this for him. His is a summer madness kit. Finished last year. 1800 Zetec. He's got a bit of a leak Here's his mail:

Issue is an oil leak (seemingly from the top of the gearbox) that runs down the edge of the gearbox and collects and drips from the lower rear end after a run. Loss of oil is pretty insignificant and a regular check will easily complete a top up with less than a cup ful of gearbox oil.

There is no continuous leak,. so after the gearbox cools and the run is over the oil that has been expelled drips then the issue stops.

It has been suggested that the overflow on the gearbox may not be long enough to contain the frothing of the oil, can I fix this withough dismantling the car or is there another possibility that I should look for ?

Hope you can help.

[Thrustyjust]

I would look to the top plate on the gearbox gasket.They are 10mm bolts if you can reach them and then unslot the plate from the top of the gearbox.Clean and fit new gasket.The other place is the primary gear oil seal that can leak,although that will definately be engine out for that one or prop oil seal,that can be done by removing the propshaft.

[Blatman]

Overflow

There is a *small* breather hole in the standard top cover. If the 'box is overfilled it just possible oil is breathing out and then pooling/dripping...

[conibear]

Yep, breather could be the culprit. Although, it doesn't necessary mean it's overfilled just because it's slightly discharging, they do it with some spirited abuse.

[stu999]

What gearbox is it? I'm guessing MT75...

[xillent]

i'll find out what greabox he has.

also,

Would extending the breather, rubber tubing type fix, be sufficient to aleviate the issue. And can you get to the breather without removing the internal aluminium bodywork plates on top of the gearbox / prop tunnel ?

[Nick A]

i am presuming it is a MT75 gearbox these have a breather in the top and they also used to suffer from oil leaks from the reverse lamp switch which is 3/4 of the way up on the nearside of the gearbox

I would check the oil level is ok first if it is overfull it may be forcing it out of the breather  

Nick

[gumstabber]

my MT75 gearbox leaks approx one drip a week from the blanked off speedo sender point, runs down the drivers side casing and drips off the base. To fix it it means engine out, but it's such a small leak it hardly seems worth it especialy as it has also decreased in frequency since I let out the excess oil that westfield had added to it. Worth checking this area too?

[zvezdochka]

Mine leaked from Speedo drive, Fixed by cleaning with white spirit to degrease then inserting washer of suitable size,held in and covered with silicon.  Not easy to get at from underneath and wear gloves as ally panel edges will easily cut back of hands.

[xillent2]

Gearbox is MT75.

Any further info appreciated

[perksy]

Sure it's not from the Rear oil seal, where the prop output flange enters the gearbox  

Otherwise as already said Speedo drive, top plate etc...

Good info' on the MT75 here including diagram's which will help find where the leaks coming from:

CLICKY HERE

HTH

[Kevin Wood]

Mine leaked from Speedo drive, Fixed by cleaning with white spirit to degrease then inserting washer of suitable size,held in and covered with silicon.  Not easy to get at from underneath and wear gloves as ally panel edges will easily cut back of hands.

A 2p coin with a bit of silicone on it fits perfectly.

Kevin