Hamish, Welcome to the BB. I am a TA21 owner and know nothing about preselector boxes however I know a very knowledgeable chap here I'm Melbourne who is a member of the Armstrong Siddeley Club. I forwarded your question to him. Below is his reply. I hope it helps. Richard Melbourne [i:v6mwxh29]With close fitting overalls and petroleum proof gloves and suitable facial covering wash the underside and back of gearbox with Kerosene and wipe dry. Park the car overnight on a level floor with a piece of white paper held underneath the gearbox, use stones/bricks to stop the paper being disturbed by wind etc. The colour and location of the oil spots will point the owner to the source(s) of the leaks. If the oil is coming out of the rear seal it needs replacing with a modern neoprene type. If it is leaking from a joint in the casing, it may be possible to plug the leak with silicone, after thoughly cleaning the area with solvent and an old toothbrush. If the oil is running down the visible threads on the underside of the gearbox, under no circumstances should these be disturbed unless a full overhaul is being done. These bolts hold the assembly together and they are not trapped(prevented from turning) inside the gearbox. When the units were new Armstrong Siddeley Motors used lead washers to stop oil leaks, ENV probably did the same thing. If your UK contact has already tried undoing some of these he can grip the exposed thread and re-tighten the nuts, not good practice, but better than the alternatives. [/i:v6mwxh29] Posted by RichardWallach 03/05/2016 11:58:42
