Yes, I wonder that also, since I run in L, and it is heard loudest with quick and hard deceleration. And it is hardly noticed with the radio on at a decent volume.I don't have any sound .... but my hearing is so- so. What I am wondering is if there are driving habits...such as running in L that create higher loading on the bearings.
That looks like M/G B to me, very similar to the picture I posted.I do believe what you are looking at is the generator, not the motor. The bearing appears to be missing the spacers between the individual balls in the race. I don't think any balls are necessarily missing. No bearing like this actually has the balls touching each other. The balls would wear against each other causing excessive heat and wear. Another thread shows all the failed plastic spacers. Bearings like this have been around for 70 years+ so a failure like this is very troubling.
This is the same problem I had. Download this file and change the extension from .pdf to .mp3 to see if your sound is the same... I think this is the third one reported. See this thread. http://gm-volt.com/forum/showthread...oming-from-Volt-Any-Ideas&highlight=solarexecTook for test drive with dealer tech. Houston, we have a problem.
Working in the best time to bring it in to get it worked on. Would like to know for sure that I get the upgraded part, regardless if the replace just the bearing or entire assembly. Tech is going to contact GM and discuss.
There's a nice CAD drawing of a PM motor on the Spark motor page here: http://media.gm.com/media/us/en/gm/.../news/us/en/2011/Oct/1026_spark_elec_mtr.htmlCool pic, though. GM doesn't usually let that sort of thing out, so I'm assuming you took it yourself at the dealer? Boy is that a lot of poles on a motor!