Either this truck shift as soon as I get on the throttle or it is taking off in second gear I can never hear it ever shift the only way you can hear it is hold the truck off the ground and it will shift twice like it is supposed to do but on the ground you will never hear it and when I first got it it would ride wheelie until you let off and it will no even get the front end in the air at all now seems like when it is cold and not warmed up yet something is slipping like it is stuck in second gear and realy struggling to pull itself has anyone ever heard of this or had the same problem