Sorry in advance for the long post . . . .


Hey all -

I have an alignment question so I'm hoping someone who knows something about alignments and the stuff I'm about to mention will know something about this.

It doesn't concern my truck, but rather my sedan, however this info might be useful to others as I'm sure this issue will come up with our trucks.

This is in regards to my Lexus, and I trust you guys here. The morons on the Lexus board are kinda scary.

I just bought new wheels and tires for my LS (Antera 329's) I haven't had time to take a pic, but when I was trying to decide which wheels to get I Photoshopped the wheels on the car to see what they would look like.





I went from the standard 17 inch wheels to 18". Did the plus sizing thing so overall diameter was not changed.

Had them installed yesterday at America's Tire Center (aka Discount Tire Center) as they always have great service etc. However they don't do alignments and they recommended I have an alignment done after new wheels and tires installed.

So I go to the Lexus dealer today and have them do the alignment. Very spiffy looking system, Laser light, Octagon shaped mirrors with dozens of small shaped octagon shaped mirrors within them . . . all very impressive.

Anyway, my car is up there for a while and finally the service manage comes up to me and sez that they can align the front wheels fine but the can't align the back and that I need to replace the control arms so that they can get the "camber" (I think I got that word right) correct. Don't replace the control arms and the rears won't align properly and cause early treadwear...

Well, I get this gut feeling that this ain't right and I say "So you want to put a different control arm on my LS? What will it be the control for, some other vehicle? I ccna't imagine they make various length control arms for each model car. And what do they do when they upgrade the wheels at the dealer? (They sell a lot of 18-20 inch wheels, very expensive chrome ones) I asked, do you change the control arms for all those cars?

He was trying to explain it to me and I just wasn't getting it, so he took me back into the garage to where they were doing the laignment. He pointed out the control arm (which means nothing to me) and said, this will need to be replaced. I said, just one or two? And he said both....

Just then the guy actually doing the alignment walks up so I ask him to explain this to me. He sez that the the two front aligned fine and the Left rear aligned fine, but that the Right rear was a little bit off. And the service manager buts in and sez "So see, you'll need to replace these." The guy actually doing the alignment takes me to this computer monitor and I see something that looks like this:



I see that the right rear has an arrow pointing right on the line between acceptable and not acceptable. I aske the guy actually doing the alignment "Am I seeing this right, this is right on the line between acceptable and not, yes?" And he sez, yeah, it's really really close. I ask if the way to fix it is to replace the control arm and he sez "Yeah, the shorter control arm will allow him to get it within spec." The service manager buts in again "If he doesn't change the arm, the tires will wear sooner"

And the guy doing the alignment sez "Well, maybe...maybe not"

Considering that they wanted over four hundred some odd dollars to replace one control arm, and I don't feel comfortable have two different length control arms on the rear of my car, and because the guy said it might not really affect anything, I decided against it till I threw it out to you all here.

Should I drive it for a while and see if the one tire wears too fast? If something like this is so close to being within spec that it doesn't matter? (I assume Lexus' tolerances are pretty tight and in the real world this is more than acceptable)

Should I have the control arm changed...should I have both rear arms changed?

Help.

Thanks in advance

K

 

I don't know Lexus', but many Fords, while being adjustable in the rear, don't always come with the adjustable pieces from the factory, you have to add them if an adjustment has to be made, and it always has to be made.

 

It does seem strange but I can see where they are going with this.
Having a different length or adjustable control arm will allow them to bring it back to spec.
These cars (even a Lexus) and are not blueprinted from the factory. There will always be some production tolerances in a mass produced car.
You don't normally need to change control arms to get the camber back on anything unless you lower or raise the car thus changing the geometry of the suspension.

I think you have 3 options.

1. Put the original wheels back on. You will probably find that the alignment is out with these anyway. You just never noticed it.

2. Live with the alignment and see if the tyre wears. It is very close.

3. Change the control arm.

If you can take the arm off yourself, you might be able to make an offset bushing, or even fit a new one to bring it back into spec.

The manager is telling you the correct thing to cover his ****. It needs a new arm to make it right and he doesn't want you coming back in 3 months claiming a new tyre.
The mechanic is being more realistic, it might be ok but he doesn't take the heat.

If it was me, and it was that close, I would let it go and monitor the tyre closely. If it stays ok, then no problem.
If it starts to wear abnormaly, I would swap it to the other side to even the wear and then get the arm fixed.

 

I've never replaced a control arm to gain anymore alignment adjustment room. Normally, eccentric bolts are installed in place of the normal bolts. With the little cam on the bolt, when turned, it presses against a solid keeper that's already on the frame or controller arm or whatever, moving the control arm in different directions to adjust whatever is needed.

I got this from AllData (not the Lexus book I know, but it's the only source of Lexus info I got), it looks like they use eccentric cams from the factory:

I'd find another alignment shop.

 

Silly question but did you have something in the trunk that was heavy. If you did it can casue negative camber. If it is more to one side than it will skew the numbers on that side.
A lazy spring on one side in the back will allow that side to sag and casue the same thing. Just a few things to look at before changing parts.

Regards

Jean Marc Chartier

 

Thanks everyone who has responded so far -

momalle1 - yeah, I figure it will always require adjustment, which is why I'm not so hot to slap on new control arms. The idea of adjustable ones is something I'll look into -

In the meantime, I'm with you Adam - I'm going to run with it for a while to see if any uneven wear starts to occur - I'm also going to look into what Quintin brought up (eccentric bolts) and see if they (or the previously mentioned adjustable arms) are available / or will work on the L . . .

Jean Marc - Salut! It's always the simple things. A good thought, but no, there was nothing in the trunk at all.

Thanks again everybody.

 

Just to add to my previous long winded answer and to expand on what JMC said.

The ride height will affect the camber. If you have ever set up a race car (yes I have) you make all these adjustments with the car loaded as it will race.
By that, I mean the fuel level is full (or amount you carry for the race) and the driver is in the car.
You could try it again sitting in the car or even filling the gas tank. I'll bet you will se a slight difference.

Another possibility is that the measurement point may be off.
The wheel may have slight run out or, if they measured off the tyre, it could be inflated wrongly.
Again, you could change wheels from side to side and see if there is a difference.

Personally, I wouldn't worry about it. From the looks of your chart, there is only 0.6 degrees (from vertical) difference between the two wheels.
Just keep an eye on the inside edge of the tyres to check for uneven wear patterns.