Due to failure to properly diagnose, I am still struggling with an alignment issue that I thought might be PS rack-related but...is not. Back under the car I go...
The alignment is off and pulls hard when driving; steering wheel is off-center ~30*. But when I checked it (string method) with the steering wheel straight and level, the alignment is spot-on. (Or is there something else going on? Ball joints, tie rod ends and bushings are in good shape. Problem does not disappear when I cut the engine, so I don't think it's PS. Earlier symptoms of asymmetrical steering effort are likely due to extreme toe out + road crown on one side, toe in on the other.)
In the garage, preparing to re-align, how do I set the wheels up exactly in their incorrect orientation as a starting point? I didn't use plates last time I checked it. If I use, say, greased aluminum plates or floor tiles this time, would the front end naturally fall exactly into its incorrect position if I simply roll the car back/forth a bit?
Thanks...
Are the rest of your angles in spec? I'd almost assume one side is very positive on the caster compared to the other side.
Have you crossmeasured the lower arms and mounting points to insure they are within 1/8" of each other? Might have a bent arm and not even know it.
Is the intermediate steering shaft/rag joint OK?
What kind of car exactly are we working on here?
Go over the front end with a fine tooth comb, in particular look at the rubber control arm bushings. A sloppy CA bushing can look just fine when the car is lifted but when you are rolling down the road the natural rearward force on the control arm can cause everything to get all kinds of out of whack.
If the car has a separate front subframe, look carefully at those bushings too (assuming it has them, for instance Miatas have a separate front subframe but no bushings.). If the subframe cocks sideways due to a bad bushing, it shows as the same problem as bad CA bushings.
It's an 89 Saab 900, 210k miles; no sub-frame; double wishbone front end; GM rack/pinion; no rag joint that I'm aware of. I put new lower control arm bushings in 40-50k ago but now, as I write this, I wonder if the uppers are failing, which would cause tons of caster change. E36 M3, they're buried on the LH side...
OK, thanks for the advice, guys -- I've got some things to check into and some measurements to take...
IF the steering wheel is off by that much you need to see if the rack is centered or off as well. Turn the wheel full left from center and then right from center, center being where the car is pointed straight ahead. Do you need to turn the wheel the same amount each way to full lock or is the amount different side to side? If the amount is different then you may be able to take out toe on one side and add it to the other to get the wheel centered.
