Alignment set for crown of the road...

[TommyArgh]

Hey all,
Lets have a quick discussion about about alignment settings for everyday driving.

My truck is 2012 Tacoma DCSB with OME lift and 285/75/16s, but this should apply to almost everyone. I recently installed SPC upper control arms and took it for an alignment. The truck came back with a rub on the body mount of the driver side but not on the passenger side. So I measured the wheelbase and sure enough the driver measured almost an inch shorter than the passenger side. I called the alignment shop and they tell me the do that intentionally because of the crown in the roads and if they made it even the truck would wander or track badly. I asked them beforehand to move both of the wheels forward because I didnt want it to rub, and per SPCs Youtube video they suggest you do if youre getting a rub. (video link ... .) They tell me to bring it back and theyll look at it again. So they move the driver forward and adjust but say they had to move it back to stay within factory specs and settings. Im a little confused because not every road is the same.

My question to you all, how many of your rigs are aligned this way?

 

[Teamoatmealpie]

Centering your wheel in the wheel well shouldn't be that big of a deal.

I have a similar set up (4Runner/285/70/17 with SCP UCA & Front mud flaps removed & body mount chop) had similar problem with a Toyota dealer- was real clear before booking appt they could handle aftermarket UCA. They are also a Toytech suspension dealer and sell lots of lifted rigs. The farted around for an hour and then came out and said they didn't know how to do it correctly.


I've read a ton of stories of people having trouble with shops that don't do a lot of lifted rigs. ( like Firestone life time alignment deal for $150 or what ever it is).

I ended up going to 4 Wheel Parts they corrected in about half hour, they corrected the caster properly so no rub.
Note I had no rub on or off road prior to the dealer experience, and after correction at 4WP all is good again.

My recommendation is to find a shop that does a lot of lifted rigs.

 

[Hoov]

As a former suspension design engineer, there is a long explanation to this, but the short answer is as follows: All roads are designed to have "crown", and that crown helps the water drain off.

Vehicles come from the factory with alignment settings that help address this issue, but that is mostly in how they set toe and center the steering wheel. Some of the settings is related to the interior cues between the steering wheel and the dash/instrument panel, such as no parallel flat surfaces to give away misalignments, and also how much effort is required to hold the vehicle straight as it either "climbs or descends" the crown. All that is pretty standard and largely irrelevant to your truck, particularly once you add in lift and bigger tires. Your alignment shop has likely put in a lot of Cross caster (difference in caster between one side and the other), which is why the wheel base is different one side to the next.

i would take it to a different shop and have them give you a more reasonable amount of cross caster, and make sure the steering wheel is straight. You may not be able to obtain factory caster settings and still maintain proper clearance to your frame structures, due to the larger tires. It depends a lot on the individual vehicle.