Shimano XTR M900 Cassette Spacer Thickness

[Once A Hero]

I seem to have misplaced the spacer that sits behind the cassette on an XTR M900 freehub, and as a result my cassette isn't filling the freehub body enough to be retained by the lockring.

Can anyone tell me what thickness the spacer needs to be please? so I can order appropriately.

I've got a 2mm and a 3mm, both of which are too thick. Just don't know if I need a 1mm, 1.5mm or something else.

 

[Tesseractoid]

Hmmm. These might help ?

Exploded Hub
https://si.shimano.com/de/pdfs/ev/FH-M900-1193/EV-FH-M900-1193.pdf

Exploded Cassettes
https://manualzz.com/doc/53869124/shimano-cs-m900-8r-sproket-kaset-exploded-view

https://manualzz.com/doc/53869123/shimano-cs-m900-8q-sproket-kaset-exploded-view

 

[Once A Hero]

First thing I checked - but doesn’t show spacers where needed, behind the cassette.

Here’s some pics of the situation;


I tried a Type P and a Type Q cassette, both have a slight gap. Should have measured it at the time but forgot, so thought I’d check the diagrams then ask on here.

 

[FluffyChicken]

The big fat silver ring on the M900 hub? 3mm iirc it a very tight friction fit. Tighter than HT2 spacers, but they will work.
Otherwise on different hubs 1mm. It doesn't come with it, the M737 did have one clipped on later on.
It's there to protect the spider.

 

[Once A Hero]

Actually an M910 hub - so perhaps more in keeping with M950 (I've got one of those in the draw come to think of it so will check), 1-1.5mm seems likely but I've seen odd sizes like 1.85mm out there.