3 miniCIM ball shifter on VersaChassis making strange sound

Hi, we are using a 3 minicim ballshifter on versa chassis. The programming team tested the drive train today for the first time and noticed strange periodic sound when driving the robot. Here is the video that illustrates the sound:

Can anyone suggest what could be wrong? The sound is coming from only one side of the chassis; the gearbox on the other side does not make this sound. I am planning to disassemble the gearbox tomorrow and check if there is anything visibly wrong. But I am not an expert at this, so if anyone can provide tips on what to look for, that will be very helpful. Thanks.

I would start by pulling the fuses to the motors on that side. Add one fuse and see if the sound continues… Do this for one motor at a time… It sounds like one motor might be running against the others.

Hi there,
Before opening up the gearbox, I’d verify that all 3 motors are being driven in the same direction. Is one motor warmer than the others? Unplug all but one motor and swap through them to see if they all cause the wheels to spin in the same direction. The sound could be the stalled motor having its breaker tripped and reset.
Good luck!

Thank you @TikiTech and @silverD ! That the problem could be the circuit breaker actually makes sense. I do not have access to the robot now, but I will test it tomorrow. As described in another thread (https://www.chiefdelphi.com/t/pdp-makes-clicking-sound-every-1-2-seconds-when-a-victor-spx-is-connected/342482?u=roborb) I believe we had a bad 40-amp breaker that found its way onto this robot. I should have discorded that breaker.