Pajero Owners Club of South Africa

Having a strange problem here, I recently had my wheels aligned and balanced and they were perfect for a few days. But on occasion the alignment is particularly bad, as in the car veers off line if I let the steering wheel go. It is sometimes to the left and then may switch (on the same day) to the right. My first thought would be wind or road curvature but often it is a windless day and as it varies left and right it can't be the curvature of the road. I spend most of my time on the highway at 100km/h plus so it is beginning to bother me. Any ideas as to what could be the cause?

take it to a roadworthy center where they stress the suspension to reveal failing balljoints and/or bushes.

Other than that you may have binding on certain wheels. have the wheel bearings checked and have the brake caliper sliding pins cleaned & greased.

Car was roadworthied 7000km ago. Front wheelbearings were done just before. Brake binding is highly feasible though - they have been noisy lately and it would explain the shudder I get with low brake force. Thanks!

Just a shot in the dark. It may help.
When you had the wheels balanced, did they switch rear wheels to the front?
If "yes", were the tyres coming off the front and now on the rear perhaps warn more on one side as bad allignment would do?
If this is true the problem could be that the rear tyres are fighting each other to treat like they did infront. With one side of the warn tyre being ratationally smaller than the other side you will get this steering action from the rear wheels.
Test: Switch rear back to the front again.