yeah i run mine in the grass all the time..i emailed alishanmao and he said the same thing that they told me on here to check the grub screw on the driveshaft rite behind the central differential gearbox..and it was only like a quarter turn loose, but it must have been enuf cuz its up and running again.. but now i must of run it to hot cuz i fried the glow plug didn't have a spare so waiten on tht... i've learned alot in three months and breaking things is a good way to learn..hahaha