BMW E39 rear tyre inner edge wear and rear camber

The most common cause is too much negative rear camber (the top of the wheel tilted inward), which makes the tyre run on its inner edge. A lowered car is especially prone. A load rating that is too low or low tyre pressure under load also wears the edges.

With 17-inch wheels the optimum is about -1.35...-1.45 degrees, and with 18–19 inch about a tenth of a degree less negative. Too much negative camber wears the inner edge faster. The values depend on the tyres and ride height.

Play in the suspension: loose rear arm bushings or shock adapters prevent a correct adjustment. The adjustment is made at the rear with the adjusting bolt, and the eccentric washer must be seated against the mount, otherwise the bolt just spins. The rear axle should be aligned every time.