Jayridium said:

Generally, I fill till it comes out of the level / filler plug hole. If the gearbox has a slight weep somewhere, or even just through the gearbox breather, it could have lost 300ml over the years.

Click to expand...

paul99 said:

Possibly things aren't as level as they appear to your eyes? Maybe tyre size and pressure differences add to that? I have the oil ready to do the same job and now you have me worried, lol.

Click to expand...

matty2332 said:

So, changed the gearbox oil on my 2005 F1 the other day. Took fill plug out first then drained off the old oil. When refilling I initially filled it to the fill hole level, however this took 1.9 litres, handbook says 1.6 ltrs and so does Haines. Ive drained it off again and re-filled with 1.6 litres, obviously doesn't now come up to the fill hole. Vehicle was level during the process. Anyone else pondered on this conundrum ?

Click to expand...