AJS & Matchless Owners Club

East Suffolk Section

Technical Tip (32) Sealing Tin Primary Chaincases

Having followed various pieces of advice over the years, with little effect, the following has done the trick.

(1) Clean the two chaincase halves, removing old sealant/oil/etc., (2) Check that the two halves are flush fitting; (3)  Apply a bead of C.T.1. sealant all around the very edge of both chaincase halves and leave for ten minutes (C.T.1. is effective but not cheap.  Can be bought from Ridgeons etc.) (4) carefully and firmly push together both chaincase halves, even pressure all round, and screw nut tightly onto central bolt to hold everything together – having ensured, of course, correct spacers have been fitted to prevent flexing when central bolt is tightened; (5) The following day, trim off surplus C.T.1. with a sharp knife; (6) Fit in place the new rubber band you have purchased from Jampot Spares – the one which is square in section, with a “V” cut to fit over the chaincase edges. Fit the metal band.  Stand back and admire!

If (1) to (5) have been carefully carried out, (6) is purely cosmetic.