740: Steering, front suspension, or something else?

[AdmiralSenn]

Hi guys. 1991 740 Turbo, ~165K miles.

Over the past month or so my car has developed a pull to the left, which is steadily worsening. A few days ago I noticed that the steering wheel, when left to move on its own, judders back and forth in a rhythm. The rhythm is dependent on vehicle speed but independent of engine speed or transmission engagement.

I know absolutely nothing about steering linkage or suspension maintenance, can anyone tell me what's going on? Obviously it's bad, and I want to fix it ASAP before I'm left without a functional vehicle or in an accident.

I've been doing some reading to try to understand what's happening but I'm moving right now and don't have a lot of time to learn at the moment.

Thanks!

[Harlard]

Put the car on stands and wiggle the front wheels with a good amount of force; along the steering axis, on the camber axis, and back and forth.

Does your steering wheel shake violently when you stomp hard on the brakes?

[badvlvo]

This isn't something that can be diagnosed over the internet. You need to shake down your front end and steering to see what is loose. Also check your tires for tread separation.

[dreamer1uk]

+1 with the above posts. How old are your tires? Also check for belt separation. You can raise up the front end and free wheel the front wheels and start your checks.

[AdmiralSenn]

Thanks for the info guys. I'll check it as soon as I have a few minutes. Luckily I'm mostly using the UHaul to move so it's not getting a lot of use at the moment. Hopefully it's just a tire, I have a spare wheel set.

[gashog]

+1 check tires.
You can rotate the two front wheels side to side.
If it pulls the other way, you've found your problem.

[centason]

There is an adjustment on the steering rack that has to due with the deflection. Its an adjustment screw under a cap(s). I believe JohnLane made mention of this in a post somewhere, but google is failing at the moment. I know that it can be adjusted so that the pulling ceases. I would try this only after the above was checked. I'd check the tie rods and bushings while it's up on stands.

[gashog]

Originally Posted by centason

There is an adjustment on the steering rack that has to due with the deflection. Its an adjustment screw under a cap(s). I believe JohnLane made mention of this in a post somewhere, but google is failing at the moment. I know that it can be adjusted so that the pulling ceases. I would try this only after the above was checked. I'd check the tie rods and bushings while it's up on stands.

That has nothing to do with pulling.
Google: steering angles.

[AdmiralSenn]

Welp. I found at least part of the problem. Passenger side front tire is utterly destroyed. I can't believe I was driving on it. Will swap wheels and see what happens.