I've got an 04' 6MT, my gear shifts are very clunky when cold and even still when warm what trany oil do you guys use? I'm thinking of using Redline MT-90 is that a good choice? Also how many litres of oil do I need?

Thanks

 

i heard on this forum that amsoil was pretty good and it made the trannys smoother

 

Once again I'll mention Shell's Spirax synthetic gear oil. Love the stuff.
Do a search. You'll need about 4 litres and a marine oil pump to transfer the oil and a 10 mm hex socket to remove the oil drain plugs. Picking up a set of crush washers may also be a good idea but not totally neccessary.