The manual gearbox shares its lubricant with the engine which is a lot to ask of any oil. As a result, regular oil changes are essential to slow down the rate of wear as much as possible – every 3000 miles is ideal. The first thing to wear will be the synchro cones, although these should still last 100,000 miles. Even when in rude health a Mini’s gearbox whines. Of more concern are untoward noises on full lock, suggesting tired CV joints; specialists typically charge around £100 per side.