Never mind four-wheel steering – I’ve lately discovered that my BMW 650i has developed three-wheel steering. I’d noticed the occasional squirm from the rear, and also a sense that the car wasn’t as directionally faithful as it had been.
It was a curious squirm, and it was getting worse, the car never quite settling, frequently needing slight steering corrections on a straight road. New rear tyres were needed too – I’d got 22,000 miles from the Continental Sport Contact 7s I’d had fitted not long after I bought this car – so this seemed like a good moment to have a four-wheel alignment. The last was done by a tyre fitting chain and I wasn’t convinced it had been done right, which I suspected to be the source of the BMW’s restlessness.
I was wrong. It turned out to be a worn so-called integral link, a ball-jointed tubular element linking the base of the rear upright to the lower wishbone. This was discovered by Sytner Tring, my local dealer, who I hoped would be able to do a four-wheel alignment accurately as well as the service the car now needed. Their inspection video showed visible movement in the offside rear wheel when it was dangling from a ramp, which would certainly explain why the car was steering from the rear. The offside front track rod arm, heavily corroded, and a tired ball-joint also needed replacement to achieve laser precision adjustments. Besides the service it looked like a new battery was needed too, the BMW having failed to start after a trip to the tyre fitters.
