A method of inserting balls into a TA synchro hub

Bob Butson

When rebuilding the gearbox on my TA it was necessary to strip and clean the synchro hub. I devised this method of reassembly as no special tools were available.

Tools required: two similar G cramps, a 1 1/2 inch wide strip of aluminium, two 2BA bolts about one inch long, eight 2BA nuts, a piece of flat bar ½ to 1inch wide, a bench vise and two small screwdrivers.

A clamp similar to a piston ring clamp was made from the aluminium strip to fit around the outer hub edge flange with about 3/8 in. spacing, fixed by the two 2BA bolts and two 2BA nuts. Clamp two G cramps in a vise and rest the outer hub on the fixed limbs. Insert the springs in the inner hub, then place in position, partly into the outer hub, then fit the clamp. Place a flat bar about ½ to 1inch wide just long enough to straddle the top of the clamp and tighten the G cramps lightly to the bar. This ensures that the aluminium clamp sits squarely on the hub and does not rise up when fitting balls and nuts. Adjust the clamp screws so that the balls may be placed at the ends of the springs. The balls should locate at the entrance to their housings. Two small screw drivers and some dexterity may now be needed. Allow the aluminium clamp to rise about 3/16inch toclear the outer hub flange, adjusting the 2BA bolts as necessary. Push a nut between the clamp and the ball for each ball. Some more adjustment of the clamp bolts will be required. Dribble a small amount of oil over each ball and tighten the clamp screws, making sure all nuts remain in position. The balls are pushed into the hub just the right amount and at just the right centering by the nuts. The inner hub can now be pushed down leaving the nuts to fall free. Check that all balls were located. If any escape, try again. At least they will be retained within the aluminium clamp. See photo…..