ok, i just got done running my t maxx. ran about 3 tanks. i noticed when i try to roll the truck in reverse, its kinda hard. forward is nice and smooth. and when you turn one wheel, they all should turn. but in the rear if i turn one, only the rears turn if i go one way with them. it used to roll so easy both directions. not its like the brake is on a little when i try to roll it backwards. any ideas? it dont make any weird noises when im running it.