Alignment Won't Hold

[azchevy99]

I need some help in figuring out an alignment problem. I have a 99 Silverado 1500, 150k miles. I replaced most front end parts: pitman arm, idler arm, inner & outer tie rod ends, and upper & lower ball joints. I then took it in for an alignment and it was good for a few days, but then the alignment went way out. I took it back to the alignment shop and they confirmed that the toe settings were way off. Any ideas what could cause the toe to change with all of the parts being new? Thanks!

[Matt_]

How much did the settings change? Positive or negative?

 

Did they mess with the torsion bars during the initial alignment or did you crank them? A generally large change in ride height via the torsion bars will usually "settle" a bit after a few days and throw the toe off.

[azchevy99]

How much did the settings change? Positive or negative?

 

Did they mess with the torsion bars during the initial alignment or did you crank them? A generally large change in ride height via the torsion bars will usually "settle" a bit after a few days and throw the toe off.

 

 

I believe it was negative toe, and it changed by around a half inch I think. No, the torsion bars weren't adjusted by me or them any time recently. Do you think it could be the center link? I can't imagine how that would cause alignment to go out, but who knows.

[Matt_]

What changed that made you think it went out? Did it start pulling?

 

Honestly it could be as stupid as they didn't FULLY tighten up one of the UCA adjustment bolts so your camber/caster changed while you were driving it... that would show up as a toe issue too. Seen it happen before. It's hard to explain if you've never done an alignment but when adjusting the camber/caster you have to perform what's called a caster sweep after you make the adjustments. So guys will usually "snug" up the bolts, do the caster sweep, and if the caster is good they'll toque the bolts down. They could have overlooked torquing a bolt down...

 

I wouldn't sweat it too much unless it goes out again. Just keep an eye on it.

[azchevy99]

I just checked and it was actually positive toe that was off. Front left was .51 and front right was .17

[Doug_Scott]

I just checked and it was actually positive toe that was off. Front left was .51 and front right was .17

 

Those numbers by themselves do not mean positive or negative. Back when I was still working on cars and doing alignments, toe was either "in" or "out". Like a spec would be 1/8 to 1/4 toe in. FWD were generally set to slightly toed out. If only the toe is out of spec, and not the camber/castor the only way is to either have something bent (like the spindle where the tie rod attaches) or the sleeve was left loose on the tie rod end and it actually jumped the threads inside the sleeve (not likely). Center link (or drag link depending on how old you are) is just a length of steel. No joints in it is there? Unless you bent it, you can forget it causing your issue.

 

Your steering wheel must not be centered when driving now either given the toe numbers you posted (assuming they lock the wheel straight up when setting toe). I would guess the wheel to be off to the left when driving down the road (again assuming that by positive you meant "toe in" was set to those numbers). What is the toe setting supposed to be for the truck? You are showing about 5/8 inch given the above numbers.

[Zembonez]

The only ways an alignment can change is is something has a lot of slop in it, you bend something, or they left something loose. Any competent alignment tech should be able to eliminate worn or damaged parts from this equation.