Mazda Wheel alignment caster out of range

Hi folks, recently I have both of the front lower control arms replaced on my 2012 Mazda 5. I did a four-wheel alignment after that in a repair shop where a wheel aligner was just installed two months ago. I didn't read the alignment report until I got home. It seems the front caster was wrong after the wheel alignment. Before the alignment the caster was good (3 ± 1 degree, ), but after that, it was out of range (left side -2.79 degree, right side: -1.21 degree). How did that happen? Should I ask the repair shop to redo the front wheel alignment?
I attached the alignment report as well as the car's specs from Mazda's workshop manual for your reference. Thank you in advance!

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njaremka

Wiggity-Wack-O-Tack
Contributor
:
2012 Mini R55
Castor is not adjustable, but since you replaced the lower control arms I would expect it to fall mostly into place. I would be tempted to ask them to verify. My gut says they didn't really measure it since it isn't adjustable and it takes some level of effort to measure.

FYI, castor helps the wheels to return to center after a turn, and helps the car drive straight down the road. I would expect if the castor actually went negative, the front wheels would turn and make the car completely unable to drive down the road.
 
Castor is not adjustable, but since you replaced the lower control arms I would expect it to fall mostly into place. I would be tempted to ask them to verify. My gut says they didn't really measure it since it isn't adjustable and it takes some level of effort to measure.

FYI, castor helps the wheels to return to center after a turn, and helps the car drive straight down the road. I would expect if the castor actually went negative, the front wheels would turn and make the car completely unable to drive down the road.
Thanks for the suggestion. I wonder if they would charge me again for the verification. Hopefully not. Let's see.
 

njaremka

Wiggity-Wack-O-Tack
Contributor
:
2012 Mini R55
Just be up front with them. Tell them you didn't look at the report until you got home, then noticed the castor numbers seemed out of whack. Be sure to mention how the car drives, and you are curious if they can throw the car on the rack to verify the numbers and see if they are really that far off. See what they say....
 
Just be up front with them. Tell them you didn't look at the report until you got home, then noticed the castor numbers seemed out of whack. Be sure to mention how the car drives, and you are curious if they can throw the car on the rack to verify the numbers and see if they are really that far off. See what they say....
Thanks Njaremka for the tips and it really helps. It's tricky to deal with garages sometimes.