Question on non-Mopar alignment results

[AR67GTX]

My wife’s Lexus RX350 wore the inside edge off the front, left tire so I had new tires mounted and alignment set by Discount Tires. Looks like the wear was due to the thrust angle off due to too much toe in and scrubbing the shoulder off correcting for the pull.

But what surprised me was when they corrected the toe on the right side up front, they said it threw the left, front camber slightly out of spec. And because the factory McPherson Strut bolts do not have provision for camber, I would need to take it to Lexus to see if they had special camber bolts to correct it.

I have alignment gauges and generally garage align my old cars myself so I’m pretty familiar with the process. But I’m not a McPherson strut guy. Don’t know much about them first hand. I can’t see how adjusting toe in on the right side would increase negative camber on the left side? Does that make sense to anyone? I guess it’s only a couple tenths out on camber but 1.5 degrees is getting a little high so I’ll take it down to Lexus and see what they have to say about it.

Does this toe in/camber make sense that I’m missing?

 

[RemCharger]

Slot the upper knuckle mount hole?

 

[AR67GTX]

I do understand how camber changes as the wheels are turned, I just have trouble believing such a small change in toe could make a discernible change in camber. Maybe the toe was out more than I realize. I don’t work with degrees setting toe on my out cars, just inch fractions.

 

[0DegreeEngineer]

Had a coworker install them on his mustang to increase camber, but if it is swinging like that I would hazard a guess that something is bent.

 

[AR67GTX]

Other than a couple usual potholes it’s never been damaged up front. Just a small backing accident and curbing the right front tire slightly. But nothing on the left side. But something for Lexus to check. And camber/caster were good before changing toe.

 

[gtx6970]

Right side has zero effect on left side.
To me it looks like your camber change on left side was caused by negative toe in 1st reading.
Positive toe in 2nd reading

Either way 1.1 degree negative camber is A LOT causing your inside tire wear in a short amount of time, especially if tires are not rotated on regular basis

 

[AR67GTX]

Actually I hadn’t looked at the + and - on the toe readings that close. It actually went from a toe out of 14 (-) deg to a toe in of 9 (+) degrees. That’s a lot more change than I was thinking and maybe that is enough to affect the camber that much. But they show the right front toe originally as -.03 (toe out) and green and the newly aligned toe on the same position as .05 (toe in) and also green. Surely both are not within the spec range. I’m not sure their - and + readings are making sense.

 

[gtx6970]

Chrysler used to offer a thinner strut to knuckle bolt that allowed a slight camber change

Most / some aftermkt struts have a slotted lower attachment and comes with a cam type bolt to adjust camber

 

[Kern Dog]

Right side has zero effect on left side.
To me it looks like your camber change on left side was caused by negative toe in 1st reading.
Positive toe in 2nd reading

Either way 1.1 degree negative camber is A LOT causing your inside tire wear in a short amount of time, especially if tires are not rotated on regular basis

Sorry, this is wrong. You appear to be repeating what you have heard and in this case, it isn’t true.
I have over a degree of negative camber on the front and I run a wide tire. 275-40-18.

I have run close to a degree of negative camber in this car and others for years with none of this “excessive tire wear” that even some alignment guys claim will happen.
Why?
The toe settings are far more crucial to tire wear than a single degree of camber. If you’re toed OUT, the insides of the tires scrub. If you’re toed IN, the outsides will wear faster.
All new Challengers and Chargers have negative camber front and rear.
To the OPs point, yes, toe can change camber on an opposing wheel. Example:
Let’s say you have zero camber on both sides but have toe OUT… as you drive, the tires are trying to spread apart more due to the toe being wider at the front than the rear. This will result in negative camber despite the static adjustment being at zero.
If you have zero camber but the toe is IN, the opposite happens. The tires are trying to steer toward each other and the camber goes positive.
This is a characteristic that I have seen with numerous Mopar suspensions and I suspect that similar situations can occur with other cars too.

 

[gtx6970]

Sorry, this is wrong. You appear to be repeating what you have heard and in this case, it isn’t true.
I have over a degree of negative camber on the front and I run a wide tire. 275-40-18.

View attachment 1733456

I have run close to a degree of negative camber in this car and others for years with none of this “excessive tire wear” that even some alignment guys claim will happen.
Why?
The toe settings are far more crucial to tire wear than a single degree of camber. If you’re toed OUT, the insides of the tires scrub. If you’re toed IN, the outsides will wear faster.
All new Challengers and Chargers have negative camber front and rear.
To the OPs point, yes, toe can change camber on an opposing wheel. Example:
Let’s say you have zero camber on both sides but have toe OUT… as you drive, the tires are trying to spread apart more due to the toe being wider at the front than the rear. This will result in negative camber despite the static adjustment being at zero.
If you have zero camber but the toe is IN, the opposite happens. The tires are trying to steer toward each other and the camber goes positive.
This is a characteristic that I have seen with numerous Mopar suspensions and I suspect that similar situations can occur with other cars too.

Let's agree to disagree.

I did alignments for the better part of 20 years . Yes. You can get away with that much negative camber.
If you run a little more toe in.

One offsets the other...to some degree.

A lot of this depends on the type of suspension we are dealing with .
An A arm suspension can get away with it more so than a Mac strut suspension.

An A arm suspension goes thru more camber swing changes as opposed to a strut suspension goes thru less cambers swings simply due to design.

 

[Kern Dog]

No offense but I've also talked to actual alignment guys that are stuck in the 70s where bias ply alignment settings seem to be their "go-to" standard. Radials can tolerate negative camber where bias ply tires could not.
I'm not claiming that you are a liar or stupid, I just see it different and my own experience drives my opinions.
Camber swing?
How about this:

I've run at 1/8" toe in for years along with that negative camber. My last front set of tires were replaced due to age, not wear.
My 2007 truck is set to SRT-10 specs which also call for negative camber. The only times that I've worn the inside edges is when the toe is out of spec.

 

[AR67GTX]

In my case I’m near 100% sure the wear was from scrubbing of the inside shoulder from constant steering correction to counter the thrust angle and pull resulting from the toe settings. This makes even more sense now that I realize the tires were toed out. I know radials are usually aligned to run negative camber. How much is too much I’m not sure. I usually shoot for a 1/2 degree.

I’m taking it to Lexus and let them figure it out.

According to J&L Techno, the alignment specs are pretty loose!

Toe front (L&R) -.05 to .13
Total toe. -.09 to .25
Camber (L&R) -1.42 to .08
Caster. 2.17 to 3.67
Rear toe total -.09 to .25
Rear camber. -1.5 to 0

From this the right toe and total toe on the front were good but they had to do something to correct the thrust angle and steer ahead figure. With the left camber out just .08 degree I suspect Lexus will say leave it alone.

Odd they even allow a toe out condition. I used to own a 17 Shelby GT350 that was factory aligned for toe out to increase turn in response per Ford. But it also caused it to dart all over uneven roads and trammeling. Some complained it caused early inside shoulder wear from scrubbing. So I reset it to a slight toe in and it drove noticeably better around town. I believe some toe in is important to counter negative camber by shifting some contact load to the outside of the tire to equalize wear across the surface. Toe out just increases road force and scrubbing on the inside shoulder with negative camber.