I had Firestone do a front end alignment and want to be more knowledgeable before returning. On a recent trip to Phoenix the vehicle wanted to drift ever so slightly left at highway speeds, and more so now.
The work order states all tires were at 35psi and vehicle road tested before and after alignment. No mention of Z height was provided or that it was even checked. Obviously the tire pressure wasn’t checked while on the rack or any mention of cargo as I’ll clarify later.
After the alignment -
I’ve learned that uneven tire pressure, not inspecting the Z height (trim), and an uneven weight distribution will affect alignment values. I will plead innocence not knowing the importance of inspecting the Z height or how load distribution can affects alignment and being guilty of not maintaining tire pressures.
I found trim height from left to right is off almost 1”, tire pressure varied by 7psi, RR lowest at 25psi, LF highest at 32psi, and there was about 100 lbs of cargo biased above the RR tire. Gas tank was nearly full.
Now that I’ve made corrective actions to Z trim, tire pressure and removed cargo, the LF camber appearing 'off' is more pronounced.
Here’s the question for those more knowledgeable than I -
How much do these variables actually affect the alignment and subsequent ride quality and vehicle handling? A little, a lot, or is it a case of being obtusely ****?
Additional info:
Front suspension and steering components are nearly new with 3k miles on them. The vehicle had been dropped 2” as shown in profile photo but has since been returned to original ride height (ZW7). The return to ride height prompted the alignment by Firestone.
A copy of alignment measurements is included for reference.
Thanks fellow TYF’ers.
The work order states all tires were at 35psi and vehicle road tested before and after alignment. No mention of Z height was provided or that it was even checked. Obviously the tire pressure wasn’t checked while on the rack or any mention of cargo as I’ll clarify later.
After the alignment -
I’ve learned that uneven tire pressure, not inspecting the Z height (trim), and an uneven weight distribution will affect alignment values. I will plead innocence not knowing the importance of inspecting the Z height or how load distribution can affects alignment and being guilty of not maintaining tire pressures.
I found trim height from left to right is off almost 1”, tire pressure varied by 7psi, RR lowest at 25psi, LF highest at 32psi, and there was about 100 lbs of cargo biased above the RR tire. Gas tank was nearly full.
Now that I’ve made corrective actions to Z trim, tire pressure and removed cargo, the LF camber appearing 'off' is more pronounced.
Here’s the question for those more knowledgeable than I -
How much do these variables actually affect the alignment and subsequent ride quality and vehicle handling? A little, a lot, or is it a case of being obtusely ****?
Additional info:
Front suspension and steering components are nearly new with 3k miles on them. The vehicle had been dropped 2” as shown in profile photo but has since been returned to original ride height (ZW7). The return to ride height prompted the alignment by Firestone.
A copy of alignment measurements is included for reference.
Thanks fellow TYF’ers.
