my 1991 535 started to have a small jerky movement to one side or the other in the steering. Very small, unpredictable movements, but made it hard to track laser straight like it has always steered. After much crawling under, researching on line, reading my repair book, I notice that the pittman arm slid up and down the spline shaft from the steering box when the wheels were manually grabbed and moved. I checked REALOEM for the diagram of the area.

YES, there is a clamp bolt and nut! It was missing!. After much moving of the steering from right to left and contortion arm twisting, I was able to re-install a bolt and lock nut. I found a sheared off nut with my magnetic probe. Have no idea why it broke off. Maybe the extreme cold this winter, bumpy dirt roads and 20 year old metal?

What ever, the car tracks beautifully now. The cost of repair....$2.38 for the hex bolt and lock nut. Rich
2003 X5 3.0 Charcoal grey 100,000
1991 535ia calypso red 168,000