Any guides for this? Changed the engine on my 1.6 dynamic so obviously had to drain gear box oil. I'm hearing reports of exploding diffs but can't quite get my head round the info and why these problems would arise from wrong gearbox oil... Anyway, what's the best oil to use and best tips for filling? Does the car need to sit level as it's currently up on axle stands, want to test run the new engine before its all back together properly- knowing my luck something's out! Cheers all!!