Whine/Screech/Squeal when not accelerating nor decelerated.

[gene]

No, this is not the whine under acceleration many of you have witnessed.

With 7k miles on my Model S, I now have a squeal from the rear of the vehicle which started out very subtle and is now quite loud. It occurs only at 25 to 40 mph and disappears with even the slightest acceleration of slightest deceleration. Meaning that the tiniest positive or negative load stops the noise. This rules out brakes and leads me to the motor bearings, ring and pinion or pinion gear bearing (I'm a pro mechanic and fairly accurate with diagnosis) except that all these bearings are in a lubricant and this has a "dry" sound. I suppose the inverter would be possible but this noise is only under zero load. It did get noticeably worse with 4.5 update.

I have spoken to service but they want to hear the sound for themselves. Maybe I'll find time next week to drive the hour to service.

I searched the forum and found nothing. Has anyone else experienced the same symptoms?

 

[Jason S]

Put it up on a lift and try to jiggle the wheels. That'll find if it is drive shaft and/or bearing related.

Also, if you seat somebody in there while up on the lift then you can leave car in neutral and do the same.

Also can remove the coverings under the car pretty easy while it is on the lift. So can open it up and check for wiggle on the shafts from the motor housing. Can get a pretty good view of everything with one of those drive on lifts with the extra widget that can lift the wheels.

 

[NEWDL]

Good luck! I'm interested to hear what the final verdict is...

I'm sorry to hear your having issues.

 

[Doug_G]

There's a service bulletin on the rear axle nuts - the nuts on the end of the axles that tension the rear wheel bearings. The original nuts could work lose over time (mine did). That could potentially be a cause of the noise if the bearing isn't loaded properly.

 

[gene]

There's a service bulletin on the rear axle nuts - the nuts on the end of the axles that tension the rear wheel bearings. The original nuts could work lose over time (mine did). That could potentially be a cause of the noise if the bearing isn't loaded properly.

I'll check with them on this one. Thx