Correct amount of oil for seven gearbox

[JonE]

I have Ruby with 4 speed box. If I am in any doubt I drain off and measure the amount that comes out. Then refill with new oil. What is the cost of a drop of oil compared to a gear box overhaul.

John Mason

John - as well as Ruairidh's point about not really knowing whether the amount is correct in the first place, your logic is counter to the point of the thread, which is supportive of the "standard" level being potentially a greater risk to oil contamination than "using a bit less", most likely in less well maintained engines...?