1997 grand voyager oil leek
 

I have noticed there is an oil leek under my car, and as the oil is red i think its the gear box. as you look at the car, it coming from the right. and it looks like it may be the gearbox sump gasket? or leaking from the side of the gearbox, where the nuts are to the side casing? if thos makes any sense? is this a common problem? and is it just a case of buying the gasket, undoing the bolts, and swapping? just want to make sure the gear box isn't hydrallic?? and will lose compression? any help?

anyone?