Hi all, I have a bit of an issue with my gearbox. I changed the oil a week ago(from the drain plug) and filled it up with as much as it could take before it started coming off from the fill plug. Funny thing is , I've heard drainage from the plug only removes about 60% from 2.3 liters should be 1.4l , yet I filled up approximately 1.9l before it started dripping from the fill plug. When I started the engine front wheels were moving the car forward on neutral(and gearbox was making a whine), so I drain 200 millilitres more from the box and it stopped. But I still have this low pitched whine coming from the box on neutral. When I press the clutch it disappears. Soon as I release it, it starts again. Please help

 

low pitched whine will be a bearing.
There is absolutely no way overfilling could cause a clutch to magically engage and move the car forwards... when you say it caused the car to move forward, do you mean the wheels were rotating slightly whilst in the air as thats very different and really not an issue?

 

Wheels almost always turn while car is in the air, but I'm saying when car was on the ground, on neutral, car was moving slightly forward. I've heard that can happen when people change oil and old deposits of oil in the transmission that break free can make the car move slightly because of the centrifugal forces(hope I'm making sense) but I fixed my problem by removing some oil, so makes me think it's not that.