Worn Shifting Dogs

[Andy Brockway]

We have not seen any wear after the three off-season competitions we ran with the square dogs. In fact the shifting seemed to get easier the more we ran the gearboxes. The square 'dog' is a nominal size, ie 1.25" square, while its mating hole is .004" larger, ie 1.254" square. This gives the needed clearance for the dog to fall into the hole. The corners do not mesh exactly, mostly clearance; the force is applied at a point similiar to a box wrench on a nut.

BTW we do not have any speed matching when we shift. The drivers pull a trigger to shift up and let go to shift down. Shifting down while running at high speed is not good for the gearbox just as it is not good for your father's car