hsp tryannosaurus 4wd box problem? help!!!

[parry]

hey guys my hsp tryanno is having a box problem it is having touble moving when i give it abit of gas when i pick it up it still has the same problem only when it revs it can move almost like something is jamming a wheel from turning? help!!!!!!

 

[MR4X4KING]

what is a hsp tryanno?
do you have any pictures of this?

 

[parry]

its the little green and blue one there just a cheap one i got of ebay for $200 but suprisingly nothing has broken and its still going all good