Now that the end cap is fitted you can go about setting the axial clearance on the armature shaft. I found that I needed to get hold of some new shims as I measured the clearance to be 0.8mm.
I don't know exactly what it is meant to be. The pdf file I refer to in post #1 says to remove the end play – I think strictly speaking that too is a bit extreme – the armature needs to spin easily but you don't want to motion of the engaging mechanism to promote a sort of whacking effect as it engages and disengages.
I sourced some new shims at a motor factors that also does repairs. The mechanic there was so shocked to see “such an old shim” that he emptied the remnants of this drawer into my eager hands and let me go without paying. I wish you all similar luck!
In the end with the shims that I have I set the end play to about 0.05mm. Basically this was achieved by adding all of the shims until you can just about get the C clip into place. Don't force it on there – these shims are delicate – you wouldn't stab feeler gauges between rocker arms and camshafts now would you? So just get the C clip on there and then remove one of your thinnest shims and that is the best you can do with what you've got. If, however, the shaft movement still seems excessive you need to measure it and get some more suitable shims. If you are smart you could even cut your own.
After the end play is set fill the little cap with grease – fit the rubber seal – and screw the cap into place, and then wipe away any excess grease that comes out.
