My 1.2 Stilo has gearbox oil pooling on top but I can't find the source of the leak. I'm wondering if those boxes have some sort of vent or breather on top that could be responsible. Any advice would be welcome!

There is a vent on top of the six speed box, underneath a grey circular plastic cap. If the gearbox is overfilled oil will come out of it. normally, you just get a mist of oil out of it over a long period which never forms a liquid pool. Check the fluid is gear oil (smells like horse ****) and not brake fluid from the reservoir above or the clutch slave cylinder which sits close to the top of the gearbox.

jim cooper said:

There is a vent on top of the six speed box, underneath a grey circular plastic cap. If the gearbox is overfilled oil will come out of it. normally, you just get a mist of oil out of it over a long period which never forms a liquid pool. Check the fluid is gear oil (smells like horse ****) and not brake fluid from the reservoir above or the clutch slave cylinder which sits close to the top of the gearbox.

Click to expand...

Definitely gearbox oil alright. It's closer to cats pee than that of a horse!

Well, that's one thing sorted. I was thinking that it is actually quite difficult to overfill the gearbox as oil flows out of the filler hole as soon as the correct level is reached. The only way you can put too much in is if the car is way off level when the gearbox is being filled.

Stilo 1.2 gearbox oil breather

Ive found the top of the gearbox in my Stilo 1.2 covered in oil and it seems that the top of the gearbox breather is very loose. The item I'm referring to looks like a black cap around the size a £1 coin. Can these be repaired or replaced, or can I secure it in place with gasket sealer or similar? I noticed my gearshift is getting notchy and I suspect the box is now gone low on oil.

At thoughts?

Edit: the part in eper is 46811729

Yes. There is a gearbox vent...
But... what confuses me is how you guys know the difference betwen a horse **** and a cat pis?! ?????

Not sure, but someone who knew what horse **** smelled like told me gear oil smelled the same. . I think the vent cap is meant to be loose. In a normally filled gearbox the oil level is way below the breather, even in violent cornering.

On level ground, I opened the fill level plug and some oil came out, so perhaps the box was overfilled. I replaced the plug in too of the box just for good measure. The original didn't fit as snugly as the new one.