My steering rack may not be centered (1 Viewer)

[yeos]

The tie rod ends are very uneven on my 2007 GX470. The passenger side has 4 threads showing while the driver side has 7 threads. I've had this issue where the driver side tire would rub on the UCA on tight turns, but the passenger side clears just fine. I can see how the steering rack not being centered would allow one side of the steering to turn in more than the other before it hits the steering stops.

Currently the steering wheel will turn just over 1.5 revolutions in either direction. The dash was replaced during a previous ownership, but I don't see any indication that the rack was replaced.

 

[Jstawgn]

The alignment front and rear cam bolt on the LCA might not set the same or one was stuck forcing the tech to compensate differently. Or the knuckle slightly bent forcing them to adjust it that way for camber.

 

[yeos]

I've been doing my own alignments actually. I'll take some photos of the cams when I have a chance.

 

[yeos]

Not a perfect alignment by me, but here are the cams and diy garage measurements using a straight edge and an angle finder.

Left Caster: 3.9
Left Camber: 0.5

Right Caster: 4.4
Right Camber: 0.0

Left side:

Right side:

 

[bigredmachine]

sounds like the alignment is pretty much good to go, caster may be a bit high on the right side but I wouldn't really worry about that as both sides are pretty even. 3 thread difference is really nothing to worry about, if it was 1/2 inch or greater than ya I would try to recenter everything

 

[Jstawgn]

How do you measure the caster? Usually they are about 0.1-0.2° less to compensate for the road crown.

0.5° camber difference is pretty big. Usually it need to be as close as the same.

Camber and caster definitely impact toe quite a bit and would be the cause you see big difference in tie rod thread showing.

 

[bigredmachine]

caster is a bit high but its more important to be close to even if you cant put it in spec for whaever reason such as a lift or the cam bolts are crusty and rusty. There s a good write up on adjusting toe in the 80 section, it will be a bit different procedure but concept will be the same

 

[yeos]

I'm more concerned with why I rub the UCA on the driver side only and it rubs a lot of the UCA. It just seems to turn in a lot more than on side thus making contact with the UCA.

Here's the story of my wheel setups vs these JBA UCAs. I bought my 2007 GX470 with 89k miles in May of last year. The vehicle has no accidents on record from 3 previous owners. The vehicle was purchased with no prior modifications other than 5th gen 4runner SR5 wheels and 265/70/17 tires. Two months later I install a set of 17x9" -12 offset, 4.50" backspace wheels with 285/70/17. I also installed a Dobinsons 2" lift and JBA high caster UCAs. CMC and front splash guard mod done, no rubbing that I noticed. I hit the trails later that summer and notice that the driver side had made some contact with the UCA. Passenger side is fine.

Fall comes around and I decide to change the wheels out to 18x9" 0 offset, 5.00" backspace wheels with 275/70r18 tires. The new tires are around a half inch taller, but the width remains about the same. I knew about the possibility of rubbing on the UCA so I took the gamble. Both sides rubbed the UCA on sharp turns. The JBAs have a wide plate necessary to fit the ball joint design they chose and sure enough it was rubbing on that part. I took a grinder to the UCA where it was rubbing and took only enough off to where I felt it was still structurally sound. The passenger side no longer rubs, but the driver side still rubs. I would totally understand if they rubbed about the same amount, but it just looks like the driver side tire turns in more than then passenger side. I'm lost here. Could my steering rack not be centered?

Passenger

Driver

 

[yeos]

How do you measure the caster? Usually they are about 0.1-0.2° less to compensate for the road crown.

0.5° camber difference is pretty big. Usually it need to be as close as the same.

Camber and caster definitely impact toe quite a bit and would be the cause you see big difference in tie rod thread showing.

I used the methods described over at Tacomaworld on their DIY alignment post. One method is to turn the wheel one and a quarter rotations left from center and take the camber measurement on both wheels, then do the same with one and a quarter turns right from center. Get the difference between the numbers and you have your caster. I've used this method on my Tacoma and taken it in to the alignment shop to verify and the numbers while not exact were pretty close and even side to side.

From a recent alignment last year on my Tacoma I measured out 3.4 / 3.6 caster and 0.3 / 0.2 camber. I took it into the alignment shop and their machine read 3.2/3.6 caster, 0.2 / 0.0 camber. While not perfect, I was willing to live with this small difference in my measurements and continue doing my own alignments. I would take it into an alignment shop, but my state is on a lockdown due to the virus.