Hi there,

My gearbox is moist, very moist, but it's not yet a proper leak (no puddles under the car yet), see picture, looks like coming from the top somewhere. I will be digging into this soon, looking carefully from the top (picture I took today is hazy), today had no time to take the battery out for inspection. But before I do that, perhaps you guys have a clue what this might be? Not the driveshaft seal, that I am 99% sure after looking at it already. Selector shaft seal perhaps? Tell me it's something simple

(The history of the gearbox is - it was out for clutch bearing and clutch change at its 80k km, at that point refitted and refilled with new oil, no problems for 4+ years and another 95k km whatsoever. I could have had slightly overfilled it with oil back then, very typical of me. Car was mot-ed roughly a month ago, the leak must have had been hardly visible, because even if it would have passed with the leak (not uncommon in my country, I would be advised that they have noticed it).

To me it looks like it's leaking on the driveshaft seal and getting thrown around by the rotating

I will triple check this, but I had a driveshaft leak on another Fiat some years ago, same construction, the driveshaft was also wet then, and got wet first before anything else. This one is totally dry, only the stuff around it (and not around it) is oily. But I do agree so far it looks like so, and statistically it's the most probable cause I guess. Can as well replace the seal, not too much trouble, cheap too, so I'd fix it or rule it out...

Also the gear selector seal may leak when there's a slight overfill. You might want to clean it up first to see where the leak originates from. It looks like to be coming from the gear selector area from the top of the box. Just check the oil level each year and top up when necessary.

Just clran it, drive and you'll see ;-)

Dismantled the battery, inspected it, cleaned it. It's defo the gear selector leaking. The question now is - how on Earth do I take this thing apart? It seems that the selector mechanism is integral with the gearbox and it's a gearbox out and take apart job? I also do not see how to take off the rubber protection hat without damaging it, I see two holders on it to stretch it and I guess prey it out, but that would have to be one big stretch even if I undo all things around it - shaft connectors, brackets, counterweight, etc.

Don't worry. Unless the leak becomes bigger, you don't really need to fix it. Just remember to check the oil level and top up when necessary. You might want to try searching the forums as I remember seeing one tutorial about this repair. It's not worth the time and effort. Don't overfill.

I have seen the guide for C514, but that's nowhere near similar I am afraid (and it does not seem too much effort, not for what I am used to at least ). If I missed the right one for C510 I could use some help. The only question is actually if it is a gearbox out job or not...