All three motors had a high pitched whine/crunching noise before they went. One of them exhibited this behavior during drive testing before I packed the car (swapped that one out at the last minute before i left Aberdeen, had to use it again at the champs).

All the motors do not now spin freely and none of them rotate when hooked up to a power supply. I was running them on a 6 cell lipo, so not over rating them and used the 36:1 gearboxes as the wheels were the 124mm ones from banebots. Nothing out the ordinary there.

All the gearboxes look fine, gears all spin without binding.

I'll see about digging the nackered motors out the bin and take the back end off to see what actually went in them.

edit - I should also mention that i broke the motors in on no load for 10 minutes on a low voltage, then a high voltage before using them. Something I don't normally bother with drills but I wanted to make sure everything was squared away this year pre champs.