gearbox oil level

[max-it-out]

The drain plug has a slight drip , so I thought I`d check the level of oil . Removed the filler plug and was surprised to find loads of oil gushed out of the plug hole . Looks like the oil level was well above the hole level . How can this be possible ? I thought the only way to put oil in was via the plug hole on the side ?
Apologies if this is a silly question - my sum knowledge of car mechanics could be written on the back of a postage stamp

[bitsobrits]

I would be possible to overfill the gearbox if it was done with the top cover off, such as done on the bench, or perhaps if the car was on single axle ramps when it was last filled.

Gearbox oil level should be checked/filled with the car sitting level. In any case, it's an opportunity to drain the gearbox, seal up the drain plug, and refill to the proper level.

[mtnjag]

Could have been filled way up with a powered pump and the plug slapped in while it was trying to drain back.

[max-it-out]

Thanks for the replies . I did try to remove the drain plug , gave it a few good yanks , applied loads of penetrating oil but it won`t shift at all . Must have been tightened with one of those impact driver / air hammers , maybe to try and cure the leak . If I can get it off , I`ll refit using some silicon sealer .

[mtnjag]

Use a Thread Sealer not Silicon.
Permatex makes a std and high temp in a small bottle with a brush.
Std should be fine