Rd400 large sprocket washer

[BCRD]

My rd400 has rear sprocket wobble. It looks like the mounting surface on the wheel is mushroomed over a bit from mileage or from previous owner buffing it with an air tool or something. I was looking at the spacer washer behind the sprocket snap ring. I was wondering if it was worn or tampered with. It measures out to an average .0765 in. Does anybody have one lying around that they can measure to confirm. The part is no longer available.

[SUPERTUNE]

I should have a RD400 wheel in my storage unit.
I'll try and remember to go there and grab it to measure the shim washer.
Chuck

[Alain2]

That ring is 2mm thick.

[Frank B]

I made my own when I installed the 520 chain conversion on my 400, just to make up the difference of the thinner sprocket. I ordered several thrust bearing washers 2 1/2" ID, 3 1/4" OD, 1/32" and 1/8" thickness.  I had to increase the ID slightly with emory cloth on a sanding drum but it did work.
Just an option if you can't get an original or need one thicker.

[BCRD]

Ya it's 1.94mm average. Looks worn. And if I do a 520 chain conversion from economy cycle do I need a different size one?

[Jspooner]

I used RD350 head gaskets on my euro rear hub with a 520 rear sprocket. Just needed to open the ID a bit with sand paper rolls on a straight die grinder. Worked perfect.

[Frank B]

Ya it's 1.94mm average. Looks worn. And if I do a 520 chain conversion from economy cycle do I need a different size one?

If you get the 520 conversion , you can also buy the shim/spacer kit from them too. I didn't get all that, I assembled the parts myself.