pinion set-up on a late type diff

[MarkinShoreham]

Can anyone help me with this little problem? I attempted to replace the pinion oil seal on my '56 minor last night. I followed the instructions in the 'official' BMC manual and tightened the pinion nut up to 140 lb/ft. This locked up the pinion absolutely solid. I then discovered that the diff on my car is a very late type that uses a 'crush collar' to preload the pinion rather than a shim system. My understanding is that the crush collar must be replaced when the oil seal is renewed. Does anyone out there know of this procedure and how to carry it out? I now have the diff off the car for closer inspection. It is a 4.22 with no oil filler hole. I guess I could perhaps drill and tap a hole thru' a suitably thick part of the casing.

If anyone can help I would be most grateful. It is silky smooth and quiet in use so I would like to save it if possible

[Mogwai]

moss sell the colapsable spacers as the diff is the same as a midget
with the new spacer in place you tighten the nut until the required preload is met. you can measure this with a dial type torque wrench or a weight or a spring balance on a measured length bar. it can wind up quite rapidly so check regularly when tightening (also you will need to remove the crownwheel 1st to do this accurately)
you could make your own level bung by welding a large nut to the back of the axle casing & sealing with a bolt or just fill up with a measured amount of oil through the breather

[bmcecosse]

The diff instructions are in the workshop manual. You could drill/ tap - or just fill a measured amount through the vent hole.