2021 EZGO 72v Express S2 High Pitch on Acceleration

[cstanley]

I have a 2021 EZGO 72v Express S2 that makes a high pitched noise when under load. This typically starts to happen around 16-17 MPH and only tends to happen when there is a higher amp draw on the motor (when going up hill, or charging down hill) however seems to dissipate when coasting. Given this information, it seems this is likely coming from the motor. It starts about 4 seconds into the video.

Any suggestions on remediation?

[Michael Eddie]

Problems with the motor's insulation or the commutator could be at fault. Degrading insulation or a worn commutator can sometimes emit high frequency noises during normal running conditions.

You might try raising the golf cart on jack stands and recreating the noise while it’s running. Also using a mechanic’s stethoscope can help you pinpoint exactly where the sound is coming from within the motor itself or if it might be related to the differential input shaft/bearings. Motor bearings can sometimes produce similar high pitched noises if they’re on their way out.