King Hauler question

[REV73]

so am I running the risk of damaging any of the gears? I haven't actually had it out of the kitchen , so the gear grinding has only happened on my work bench with the wheels in the air. maybe on the ground it won't be as bad? any thoughts...and what is the best way for me to get a more realistic speed with this truck, I can already tell that it is going to be way too fast and the last thing I want to do is roll the **** thing.