Terra Scorcher

[bubblewrap]

Hello! I had just begun building my absolute first Tamiya RC - the 2020 Terra Scorcher. There were frustrating newbie moments for sure: plugging the ESC to the wrong CH ports on the receiver and thereby being unable to do the high point setup etc.

Anyway the first time i managed to get it running i tested it, had a blast, got a few knocks, and then the wheels didn't spin even though you could hear the motor working. Took everything apart and i think it was a loose pinion gear on the motor shaft flat. After tightening the grub screw the wheels now spin properly when the car is upside down on my work table.

Unfortunately the moment i set it on the ground it emits a whine and doesn't move when i throttle. The moment i pick it up of course it works. Can anyone help please? 

I googled it and some sources talk of a slipper clutch problem? Does my car even have a slipper clutch? The manual makes no mention of it.

Any and all advice would be very much appreciated.

[J@mes]

The tiniest amount of threadlock on the pinion grub screw will prevent it undoing once tightened. 

[TurnipJF]

Your car does not have a slipper clutch. 

Is the pinion grub screw tightened against the flat portion of the motor shaft?