Serviced the gearbox on the 420 SEC; the handbook specifies adding 7.7 litres.
I added 4 litres with the engine off, started the engine, and attempted to add the remaining 3.7 litres, but I could only add an additional 2.7 litres before realising I need another litre of oil.
The instructions instructs to operate the vehicle through its gears after adding the whole volume of 7.7 litres.
Having put just 6.7 litres, which is 1 litre short, I opted not to engage the car's gears and turned it off until I filled it to the full 7.7 litres.
Is there an issue with not having engaged the gears? I am concerned about the gearbox sump overfilling and maybe leaking overnight.