Gearbox oil change

[Llessur]

I've changed the oil in my J-type overdrive manual gearbox - do I need to re check the level after some driving to account for the overdrive unit taking up some of the oil, or will the OD not have drained when I drained the rest of the box via its sump plug? Cheers.

[Clifford Pope]

I think it's considered a good idea to drop the overdrive sump and clean the filter - there's a magnetic ring too to collect swarf. That of course would drain the OD oil as well.

[Carboy0]

If you drop the O/D sump, you’ll need to replace the gasket.

[Clifford Pope]

Not if you are careful