Gearbox oil change

[french dave]

Hi,anyone know what size Allen key required for gearbox drain/ fill plug?whats access like -or shouldn't I ask?

[KKson]

On my gearbox it's a hex head so I just use an adjustable spanner.

[colin mee]

Mine was a hex too.but it was rounded off.so worth thinking of a new one.colin

[KKson]

Probably rounded off because some lazy bugger used an adjustable spanner!

[adam quantrill]

If it's a socket you may find it's 1/4" drive square, not hex at all. So just use a short extension bar and/or ratchet. Certainly the diff fill plug is like that.

[KKson]

Diff plugs on mine are 1/2". I just use my 1/2" rachet with no socket on the end. Gearboxes on both 350i and 390 have hex bolts but in different locations?