Saving Old Seagulls

as you may have gathered, having a concerted attack on fettling the flock to get them into as prime a condition as poss

WSC ..failed totally in France, very nasty graunching noise from the bottom end ....great engine, no prop turn

stripped out the offending box to find crown wheel totally stripped of teeth in a sludge of oil and metal filings ....oddly, pinion however seems OK
(subject to much cleaning and a magnifying glass)

got all the bits to re-furb, but in thinking about the re-assembly, and NOT wishing to replicate the original condition,...

there is a thick-ish spacer washer behind the crown wheel at the back, ie the dome cap end ....this obviously determines the meshing of the crown wheel and pinion

do these come in a variety of thickness ?
is there a range of packing shims to get the correct 'mesh' ?
If so, how do you re-assemble to get the correct mesh ?...or is it trial and error ???
or perhaps this just Seagull basic engineering ...one size does all ?

as always gents, any tips gratefully rec'd

prompt answers a bit urgent....
HID going out with the offspring, so had intended to blast all the bits in the dishwasher in this 'window of opportunity'...I think we've got enough detergent

Important bit first.

In my experience IT IS ABSOLUTELY ESSENTIAL that the current primary woman should UNDER NO CIRCUMSTANCES have any grounds WHATSOEVER to begin to suspect that you have cleaned anything that has even been near an outboard motor in the dishwasher. Or anything related to a motor car. Or a shotgun. And they have very sharp eyes - don't think that 'it's only a fuel tap she won't notice it at the bottom of the cutlery basket'. She will.

It would be seen as comparable to, say, giving the family kitten a 'linen' cycle and 1000RPM spin complete with stain remover. It's that serious a crime, really.

This can result in an unintended flying lesson, or worse. For some strange reason female people seem to believe that only stuff that comes into contact with food should be put in the dishwasher. I know it's odd, but it's there, and we sensible chaps have to just accept it. A deranged female can be more dangerous than a blowtorch near an almost empty petrol tank.

It is a fine method of cleaning out a tank, and it won't be necessary to point out to anyone that we're dealing with a powerful caustic agent here. Bare steel will be stripped of any trace of oil, and when it comes out squeaky clean and nice and hot it should be treated to a liberal coating of oil, otherwise the rust will start in a trice.

Oh, and yes, John will be able to supply different thicknesses of thrust washer, I am sure he can lay his hands on more than you can shake a stick at.

I feel I may have just saved someone's life. I do hope I'm in time....