HELP! Gearbox leak, garage muppets!
 

Hi all, I had my centre diff replaced recently on my classic, gear box before was bone dry. After it came back it leaked from the prop seal badly.
They admitted they hadn't replaced the prop seal with new so carried this out. It then came back. After a few miles clouds of smoke started coming off the exhaust where the prop had dropped oil on it.
Was again returned today, they cleaned it down tested, said it was fixed and it's still dripping!
I've used this garage for years, I genuinely believe they aren't trying to flip me off but suspect they are doing something wrong? Any ideas what? I figured overfilling, but it's now near the minimum and still dripping :(:(

Presumably they pulled the box out? I had an issue with a 6 speed when it was fitted the breather line near the top front got trapped and as it got hot the pressure had nowhere to go and pushed fluid out the prop seal. Worth a check as was an easy fix.

Thank you very much! I will check that out.