The mammoth st is very good handling truck but it has issues with the front and rear differentials. The two speed trans is a locked center drive instead of a single speed differential and that puts alot of strain on the diffs in the front and rear. The diffs need to be disassembled and shimed and most people change the two speed to a single speed center diff and that costs about $60. The chassis is a little thin and it needs aftermarket braces to make it durable. I have one on my work bench right now that I am beefing up for a young kid and I drove this truck in the fall before it went haywire and it is taking quite a bit of parts to make it bulletproof.