Aloha,

Seal in place and no oil leak (from this particular area)!

The lip to hold the seal was in a rather poor Sri Lankan-shape like some other parts of this bike has been, ended up glueing the thing in place. Time will tell if this was a good idea or not. But as for now; Great Success!

/simon

I had some problems installing the seal because of the REME-made reinforcement of the carter. I had to remove part of the lip.

That REME modification was also done in brass and they are usually held in with countersunk screws, not rivets as on Hans' example...However, I think it is a rather drastic solution as a large hole has to be machined in the casing....

I made up a jig to enable the centre of a worn seal housing to be accurately determined, clocking up with a DTI to ensure accuracy.....

On most cases the seal housing boss can then be remachined true/round and either an oversize seal fitted or a thin aluminium ring machined up and fitted to restore the housing to the original dimension....Ian

email (option): ian@wright52.plus.com

Wasn't the whole idea of that thick seal with no backing to allow for variations in the height of the drive pinion caused by the shims used in order to get proper meshing of the gears ?
If so converting it to a fixed rather than floating seal would defeat the whole design.

email (option): bsansw1@tpg.com.au

If the drive gears are meshed correctly and the mag base and crankcase platform are not worn, the centre to centre dimension between the intermediate gear and the mag drive gear will be pretty consistent (in line with the running clearances of correctly meshed gears and the machining tolerances of the crank case mag mounting and seal housing etc.)

As a consequence the relationship between the the drive gear position and the (fixed) seal will also display an equal degree of consistancy...

Shimming under the mag allows for compensation due to wear and machining tolerances to ensure that the relationship is correct and/or maintained within those limits...

The seal itself can compensate for a small degree of inaccuracy whilst still maintaining a viable seal but correct positioning of the various components is pretty much essential...The seal should not be 'floating' in its housing. That condition is the result of wear caused by incorrect initial set up and/or running with loose mag straps for extended periods....

The fit of the seal into NOS crank cases or any good used crank cases is a light interference fit....Ian

email (option): ian@wright52.plus.com

Interesting as always Ian!

/simon

email (option): SimonofSweden