Alignment ?

[70GMCer]

I just got my 70 back from the alignment shop & have a question before calling them back. The truck drives straight & doesn't pull when braking. The problem, (if it is one), is it that when I make a sharp turn left, the left front tire squeals on hard pavement & I can feel the left front end kinda sloping downward & pushing. When I turn into my gravel driveway, the left front digs/plows into the gravel as I am moving. The right side doesn't do this.

Now the mechanic that did the job, told me the alignment turn out perfect, but to drive it a couple weeks and bring it back for a recheck. That kinda sent a flag up. I didn't ask why, but he said he was getting in a new Alignment Machine in and wanted to recheck it.

I was going to call him this coming Monday to ask him about this, but wanted to get some feedback here first. I did notice that before I took the truck to him, there were about 4 shims on each side of both upper control arms. That many shims had been there before I did the disk swap. Now, there is only 2 shims on one side of the adjustment bar on the control arm.

Did I mention I just finished converting to disk brakes. I use 84 burb spindles with new outer tie rods, 71 1/2T lower control arms w/84 new lower ball joints & 84 burb upper control arms, 71 1/2T inner tie rods & center drag link. Could me using the 84 upper control arms, be causing the problem, or should I use the 71 1/2T upper arms? All parts fit perfect.

Again, keep in mine that the truck drives straight and doesn't drift from side to side, and brakes perfect. I just don't think that the left tire should be squealing, and I don't want to start a bad tire pattern on new tires.

opinions/advice?

[LONGHAIR]

Man, there could be several things causing that, but first a few questions.
1) You said that you used the '84 spindles...meaning the stockers? not lowered?
2) Drop springs?
3) Did you compare the spindles to the originals? The mounting points (ball joints, and tie rods)
4) Steering stops? Is it turning too far to the left?...not enough to the right?

[70GMCer]

They are stock spindles and stock springs. I did compare the spindles to a set of 71 stock spindles and they matched up. I used new lower ball joints and outer tie rods for an '84. The truck seems to be turning the same as when I had drum brakes on it. There's no binding or noises other than the squealing from the left tire when in a full turn.

[70GMCer]

any more ideas?

[LONGHAIR]

Not really, I was initially thinking that maybe the tie-rod attachment points were a little longer or shorter from the spindle centerline. This would change the "Ackerman". Basically, "Ackerman" makes the amount of "toe-in" change through the steering range. As a turn gets tighter, the outside tire needs to steer in more than it did for a lesser turn.

Can you tell if the tire is squeeling because it is turned too far...or not far enough?

[70GMCer]

When gradual turning, no problem. Only when I am making a full turn, is when the tire squeal. I talked to the alignment shop Monday, & the guy who did the alignment, said to give him a call on Wednesday, saying that he hops the new machine will be in.

I will mention the "Ackerman" term. Would the tie rods/toe in adjustment cause this?

thanks for helping

[LONGHAIR]

Sorry man, I was out for a few days....My cable moden had a melt-down.

As to your question, no. Ackerman is determined by the distance from the spindle centerline to the outer tie rod mounting point. It is built-in to the spindle and can't be adjusted. That is why I asked about the original parts.