Funky wandering

[Highlander]

I felt this a little bit last fall, but now its gotten worse-so much so that I'm looking into it now. On roads that have tire grooves worn into them (not the ones intentionally put there, but the ones created by tire friction) my wife's T4WD ('85, 234k miles, PS, no AC) wants to steer itself creating quite a bit of wandering side to side. I drove it up the canyon last night, and it wants to follow the camber of the high spots. So if you move from the lowest point of the wear groove to, say, the left, the car steers to the right, suddenly , as it goes up the side of the tire groove. The car also sits ~1" higher in the front (at the bumper-3/4" at the wheel center) than my other '85 (but not in the rear). There are no noises when bounced up and down (so no loose nuts/bolts attachments).
I put new shocks and strut inserts on both '85s at the same time 2 years ago, new ball joints and CVs on the '85 in question, had it aligned after all of that work as well. There is no unusual movement in the front wheels when placed in the air, steering locked, and wheels pushed/pulled/raised/lowered. There is no vibration or change in the steering feedback when it does this.
The other weird thing is that if I grasp the RR tire and flex it front to rear at the vertical centerline, I get a groaning sound from the axle area- almost like slipping brake shoes when you park on a hill with the e-brake on, but not tight enough, so it rolls when you take your foot off of the brakes. This doesn't happen on the LR though.
I'm suspecting the radius arm bushings, as the front has been (almost) completely covered, but the height difference has me wondering if its a camber issue as changes in camber can create changes in steering direction.
Any thoughts?

[Petros]

You did not say anything about the tires, make sure the pressure is correct (I like to run 35 psi because I hate soft and mushy feel of 26 psi factory pressure), and also verify that the tire is not bulging or delaminating. Takes a careful eye, but if you jack it up and allow it to spin freely, watch carefully the tread pattern. As you stare at it in one spot with the tire turning, the tread pattern should not wander or wiggle in and out as it rotates. If it does, either the tire is defective, or delaminating. You can also try the "thump" test, it should sound the same all the way around.

Radius bushings, and even the front sway bar bushings could also cause this, the anti-sway bar is an intergral part of the suspension that locates the tires, if any part of it is not held fast by the bushings it will affect the handling.

All of these are fairly easy fixes, it is just a matter of finding out where the problem is located. I do not recommend randomly changing parts, unless you know the parts are bad; you need to find the problem before you can fix it.

Good luck.

[Highlander]

Randomly changing parts is just what I want to avoid. I haven't checked the sway bar bushes yet, nor tire pressures-but I felt his last winter with the studs on, so I'm pretty confident that its not JUST the tires (though they may be contributing as they are a couple of seasons old). I'll check the tread as you recommended, Petros. In the mean time, the wife is driving my '85 and I've got the '83 with the new engine (still trying to get the mpg back up on that one) to play with .

[Highlander]

I found the culprit- It's been about 3 weeks since the wife complained about the way the car was driving, but the F-350 was in pieces, so I had to attend to that. This weekend I had a chance to get to the '85. Lo and behold, when I lifted the car and took a good hard look at the front end, both of the ball joint boots were broken! Now, bear in mind that I changed these out just 2 years and 30k miles ago. I had a new one on the shelf, so I replaced one with that (high quality this time), put the old one in the vise to see what it was doing, and it was sticking- It would hold its position until a lot of force was applied, then it would suddenly move, repeat-AMAZING! That's just what the car was doing!
Long story short- DON"T cheap out on ball joints, these came from Rock Auto- Mevotech Brand - Unless you like pulling the ball joints out (not too hard, but it's the time element that gets me down) go high quality. The cost difference is about $25 per, but what's your time worth, and possibly an accident due to severe and sudden camber changes?

[Highlander]

Just an update- I feel rather foolish, during an episode of 'bad drain plug gasket' I had an opportunity to look closely at the front tires on this car and saw that they were wearing the outsides. Checking the camber showed nothing out of whack, but the toe was wrong by 1/2"! Returned the toe to spec and it now drives beautifully. So part of the problem was cheap ball joints, and part was incorrect toe setting. It's a mystery as to why the toe changed when I didn't change anything that affects the toe Anyway, weird stuff happens and sometimes you learn from it