'89 900 Randomly Pulls Slightly Left or Right at Highway Speed

Sounds like tramlining? What kind of tires have you got?

Hi Mark, yes, might be caused by a worn steering rack. Or air in the steering-system. Allthoug that might not be a real "pulling"... but feels more like the car is not wanting to go straight ahead by itself, you continuously have to correct it.

Other things to check are wheel-alignment (!) and tire wear or damage. Did this appear all of a sudden? Or did it gradually get worse?

Good luck, Richard.

How ?

Graham

"Eeyore" schreef in bericht news: snipped-for-privacy@hotmail.com...

Hi Graham, depending on what exactly is worn I suppose there will be "play" in the steering rack. The steering valve (not sure how it is called in english) or "commander". Also the connection with the steering rods can be worn.

I would start with checking all the other possible causes like alignment, suspension and steering rods. The steering rack is the hardest and most expensive to replace. And as I understand the most common symptom of a worn steering rack is stiff steering or vibrations at low engine speeds.

BTW: Wheelbearings with excessive play can also cause "wandering" in the steering at speed.

Richard.

to test balljoints properly you need to unload the suspension. Wheels can 'feel tight' even if the balljoints about to pop out.....

if the front end clunks badly on rough roads thats also an indication of worn balljoints....

also if they do need replacing do both sides. They invariably wear at the same time, usually every 130K in my experience....

Thanks for the info Richard. It did appear rather sudden. I do have new ball joints for it but I only got a chance to replace the right upper one last year because it was clunking on the right front side but after replacement it still clunked. I'll replace the other ball joints to rule them out as suspects. This vehicle has 120K on it so they need to be changed anyway. I think that the pulling problem is most likley due to worn ball joints (my 9000 did exaclty the same thing before the ball joint broke and almost killed me) but I'll have to change them to find out. Driving on worn ball joints is extremely dangerous so I will replace them ASAP. BTW, if the pulling problem is because of a worn steering rack is there a chance of losing the steering completely? Mark

Thanks for your input Fred. I'll rotate the tires to rule them out as suspects. Mark

Thanks for your input. I will replace the balljoints ASAP

Hi,

You should understand how to test things 'cause you can replace nearly everything and still miss the fault.

1. I guess the suspension on the 900 1989 is the same as that of the

1983 and 1979 models I had. As it has already been mentioned you have to unload the suspension (mentioned previously) ... basically with the car on the ground you must jam up the upper wishbone (follow the procedure for removing drive shafts and similar or post to explain what it is). At that point both upper and lower ball joints will be without load.

1. Next test. If you can suspend the front of the car you can pull the wheels in/out as if you are testing for toe in/out. On my last 900 there was enough movement to foul up the aligning tool at the tyre place (and that was with the wheels on the ramp). Further checking showed a marginal movement of the steering knuckle (ball joint at the end of the steering rod). It was safe no problem but that one millimeter of movement was enough to produce too much wear on the tyres.

2. the above test (or similar) should show you if the truck rods move in/out of the steering rack ... which is what you asked for.

1. Worn wheel bearings can cause excessive play but you should be able to hear them. Loose wheel bearings can cause excessive play.

2. The wishbones themselves (where they pivot) could have play.

And all the other things already mentioned.

Regards Charles