I've got a firehammer buggy that has been upgraded with a 30 cc kit and tuned pipe. I thought the clutch was slipping and replaced it today. Got it all back together and went to run it . Blam. Same problem. Come to find out it's the gear slipping on the diff gear. It seems to be caused by the rear of the car flexing. I tightened all the bolts and nuts. Started it up. Same thing. Does any one have a fix that would stiffen up the back half so it won't flex? I'm sure this is caused by the added hp from the mods. Someone please help.