Numbers hand-engraved on inside of XS1100 final drive?

[Bummer]

Please refer to Yamaha Shaft Drive Service Manual [1J7-28197-19] page 39 describes where to find the scribed original drive shim thickness for both the middle and final drive cases.
Scribed number towards engine is for the Final Gear Case Drive Pinion Side shim.
Scribed number towards the rear wheel axle is for the Final Gear Case Ring Gear Side shim.
If I could find a my PDF file of this manual I could try to attach it if that would be helpful?

[steptoe]

I’d agree with Christian, they’re on every diff Ive handled

[Christian Raith]

Pretty sure they are to indicate the shim sizes???

I am sure someone here can explain these hand-engraved numbers on XS1100 final drives. They are in two different areas of the final drive. I always thought they were some clearance measurements recorded during assembly for some station down the assembly line, but they don't look like that.

[Turd Ferguson]

I am sure someone here can explain these hand-engraved numbers on XS1100 final drives. They are in two different areas of the final drive. I always thought they were some clearance measurements recorded during assembly for some station down the assembly line, but they don't look like that.