Oil Seal Red Primary Gear | Classic Mini

With the cost of new primary gears spiralling ever upwards, and the availability of good, serviceable used ones, fitting new bushes to existing gears is becoming a more common solution.

Assembling the engine to gearbox (transmission) is explained and simplified in this article. Contrary to popular mis-guidance, all BBUs will fit all four-syncro gearboxes. It was only the three-syncro boxes that varied in casting dimensions causing hassles where 1275s were applied to 850/998 gearbox casings. The longer throw and bigger crank and rod assembly dimensions fouled the sculpted areas in the gearbox case,