Pinion shaft diameter

[Stuart Giles]

I believe the 1" shaft can be fitted in a later casing 'simply' by adding a sleeve; and likewise a later pinion shaft can be made to fit an earlier casing by turning off the 1 1/8" section.

You could get the later pinion ground down to 1"; it's too hard near the actual pinion gear to turn it. But the 1 1/8" pinion can be fitted in the earlier casing simply by using the spacers for the 1 1/8" pinion along with the later roller bearing. Not sure it's actually necessary to drill through the casing and put that peg in to stop the roller bearing's outer moving. But on the couple of occasions I've done this mod, I drilled and tapped the casing, screwed in a bolt with some loctite from the inside and cut off the "spare" length of bolt shank and head.

With Roger's nasty noise being on drive only, it is possible that the problem is with either the pair of thrust bearings or the retaining nut having come loose, although the graunching noises are usually on the overun when that's the problem.