74 850 rear brake backing plate

Question on backing plate to drum on rear 850 1974:
using old brits diagram of back wheel pt # 21 NME5276 Washer, Flat AR

does this go on the outside of the drum against the backing plate
and is AR 'as required' ?

Everything is bolted up and tight but the backing plate is loose, it rocks, too much.
So does the washer (s) take up this slack?

That washer actually sits on the end of the dummy axle, so it does end up between the drum and backing plate, but it does not bear on the drum. It bears on the shoulder of the dummy axle. Both of my bikes have exactly one, but AR does stand for "as required". It is a very thin washer so I suppose it is more of a shim. Frankly I don't know what the manual says about it. I just know it is there.

Russ

Thanks the drum is off one bike the backing plate another. Perhaps that has
something to do with it. There is some play in the backing plate and
I suppose it doesnt matter as it firms right up when the brake goes on.
Backing plate has to float to work really.
I do hate the whole stock rear wheel and brake. It weighs more that
my house.

Yeah, putting that whole rear assembly togetther is a big pita.

So far it is all static, bike has no engine right now but seems ok.
New buffers in the hub, drove then in with a big lead hammer liberally
covered in washing up liquid. Then relubed and introduced the drum
with the lead hammer. Left it sit for a week. Then built assembled
the entire wheel unit before inserting into the swinging arm.
Used Madass's new one piece axle. Introduced original long side
axle from stub side to help align and then drove it out slowly with
the new SS from the right side. Went well.
Next summer when it gets road tested Ill report back. Long wait!