5HP18 Archives - Transmission Digest
Going Bald

Curve-recognition programs in BMW’s 3, 5 and 7 series with bald tires can make your head go even balder. The purpose of this strategy is to prevent shift business during turns for driver pleasability. Recently we had a call where a shop was distraught over a 530i with a 5HP18 that had no upshifts to 4th or 5th under light to medium throttle and no upshift to 3rd under heavy throttle. Much was done and replaced to remedy this complaint when all along it was one tire being a different size from the other three.