I am still new to the hobby and don't know all the parts of the car.

XTMer said to clean out the case well and grease it. What case is this? is it the case in the back center that the axles of the back wheels attach to? Do you need to use a special grease or would lithium grease be good enough?

also, i read a post saying that you need to check the gear mesh. can somebody clue me in on how to do this? what do I look for in it?