What is it?...and where does it go?

[Wadda]

I pulled the faceplate off the freewheel side of an MP3.

These two thin washers fell out from who-knows-where.  The $2 coin came from my pocket.

I don't see a reason for them.  Where do they go; and what are they for?

The $2 coin I've figured out.

[Bikemad]

Those are spacer shims, which are fitted on the axle before the cover goes on.
They are needed to remove excessive end play between the bearing and the stator, therefore preventing the hub assembly from moving sideways on the axle as indicated by C  below:



Alan
 

[Wadda]

Oh, righto.  Makes sense now.

I had placed them on the shoulder of the shaft, but when I put the faceplate back on the faceplate wobbled until I snugged up the socket head bolts around the perimeter...

Without the washers the faceplate laid flush...I just never checked for play in the "C" direction.

Thanks.

[Bikemad]

It would appear that GM have taken notice of one of my previous my posts regarding bearing play and are now using solid shims instead of the wavy washers to preload the bearings, which should considerably reduce the movement indicated by B.

It's reassuring to know that someone at GM is obviously paying close attention.

Alan
 

[GM Canada]

After several years of reading your posts it is clear to me that everyone should be paying close attention to your thoughts.

Gary

[Wadda]

He is a valuable reference...(since GM reads this...)

[Morgen 3Eman]

Hey, GM, not only is Alan knowledgeable, thoughtful and smart, he is also tall and good looking!

Seriously, Alan, you are a treat to have on the site.

Sincerely,
Dennis

[Bikemad]

Hey, I wasn't fishing for compliments, but thanks for the vote of confidence guys. 

Alan
 

[Morgen 3Eman]

Awwww, and he's modest,too.

Dennis

[MelbourneRider]

That's what they are for... darn..! I didn't know what they are and I have left them out too when upgrading the phase & hall wires.

Will it do damage to the pie if I left them out? How bad will it be without them?