BL motor not working - what can be wrong

[wallot]

My good old (6 months) GH4700 (Duratrax Vendetta ST on 2S lipo, 13/45 gearing) motor kinda died on saturday race (did cost me my third place in A-main)

When truck wheels are off the ground they spin no problems but whn i put the truck on ground it barelly moves. It makes grinding noise and moves very slowly like really really bad cogging.

It is motor problem as my backup feigao 280L moves the truck as it should.
What can be wrong? Bearing dont look that bad but I can try to find new ones - 3x8x4

I would understand if the motor did not move at all but this is strange.