Hello. I'm working on my little brothers t maxx 3.3. The clutch shoes were broke. I replaced them and the spring. I put it back together and if I start it and hold it up the tires move when I give it gas but when I set it down to drive it, it revs up but does not move. I've got myself stumped on this. I would be very thankful for any help. I'm trying to get it done before Christmas morning.