Well hello,

I would like to know which oil I should put in the diffs (Front, center and rear) for bashing.

I think most people are using lithium grease rather than oil. The diffs are not sealed so oil will eventually seep out and, if it goes unchecked, you will end up running with dry diffs and have a bit of repairing to do.

Genesis diffs are sealed.
i use 10000 front and rear and 300000 in center.

Thank you.

are you sure 300.000 or 30.000?

Yes i'm sure it's 300.000 it's like jell. I have 300.000 in my center diff because now it's more like locked diff.
But if you want to race your gen i think you should use 100.000 or something I think CEN team drivers use something like that.
You can ask them at www.teamcen.com.

O.K.

how often do you think I should check or change the diff's oil?

Racing I use 5000 in the front 20000 in the center and 1000 at the rear.

while we are on the topic of differentials, how much play is acceptable in the pinion shaft? ive got to replace both transmission gears, and ive got my MT2 torn down all the way. i noticed that the bearing fits well on the pinion and there is no damage to the differential housing, but ive still got some side to side movement in it.