Alignment shows rear toe angle off - tires feathering and cupping

I know I have seen other alignment sheets on here with the rear toe for one wheel up to .30 degrees. I have also seen total toe numbers for the rear at around .20 degrees. My 2017 Tacoma has a total toe in the rear of around .20 degrees as well with one of my wheels being around .30 degrees and the other around -.09 degrees.

My issue is that my tires are feathering and cupping pretty bad. I have tried to take the truck to the dealership and they say that this is perfectly normal for the solid rear axles on these trucks. Has anyone else tried to go to the dealer about this and ran into this same issue?

I know that with machinery tolerances it isn't going to be zero and I also know the alignment machine sensors have some inaccuracy, but I would think they would be reading closer to zero than what they do.

Also, has anyone ever had their front wheels aligned to the thrust angle? I tried to ask the service tech if he was aligning to that and he kind of gave me the run around so I never really got a straight answer from him. Could this perhaps be because he didn't know what I was talking about?

This wouldn't be a huge issue to me, but my set of Cooper Discoverer AT3s only have about 30k miles on them. I have rotated them every 5,000 miles, so I feel like for them to be feathering and cupping there are underlying issues.

Also in driving, my truck drives fairly straight, the only issue I really have is the steering wheel seems to be off just slightly when I am driving on a straight road.

 

Concerning your last paragraph.
If it's pulling to the right, that's totally normal.
Crown on the road and vehicles are designed to do this to keep them out of oncoming traffic in Case of a sleepy driver or medical emergency/unconsciousness.

If it pulls to the left, you have issues that need to be addressed.

 

Thanks for your input @Matic. It is pulling to the right just slightly and that basically only occurs on interstates where there is crowning, so that makes sense.

 

What rotation pattern are you using?

 

@splitbolt i have actually had it serviced at the dealership every time accept for this last time at 30,000 miles. Who knows, they may not have even been rotating them... I just rotated myself the other day for 30,000 miles and crossed the fronts to the back and brought the backs straight up to the front. Whats interesting is my steering wheel is vibrating pretty bad at times now since i rotated my tires. I suppose that is because of the feathering. i have included an image of my latest alignment numbers.

 

I know exactly what you're talking about...
I've seen the exact same positive thrust angle on many 2nd and 3rd gen alignment sheets.
Not exactly sure what causes it; frame twist, bushing deflection, spring fatigue due to axle wrap...
I strongly suspect Taco lean is related to it.
Worse case I've seen, is when it shifted from a negative to positive thrust angle between alignments.
Out of curiosity, have you ever checked torque on the u-bolts?

 

Same issue here. Truck pulls a little to the right after alignment. Didn’t pull at all before alignment. I wonder if improper alignment head attachment could be the culprit.

 

I love it when toe changes on the print out of a rear of a solid axle vehicle, but I digress. On a rear wheel drive vehicle you want a little positive toe in front because the tires tend to open up when pushed and ideally toe is at zero so you don't get wear. Obviously on the rear this can't happen an total toe should be close to zero. If you have positive toe, it will cause feathering and edgewear to the outside edges of your tires. Unfortunately there is no spec for the rear so you will always be told it is normal.

 

Just throwing this out there. There was a bad batch of axles mentioned a while back. They were bent? It was said to be the source of problems with the rear brakes. Something to look into?

 

Toyota recommends just straight front to back swaps, no crossing.

 

That is only for the US. Other markets are shown to do crossover rotations. Given all the cloverleafs here and goofing around on them, I did a crossover after I got back home from 10k service.

I do this for any non-directional tread pattern.

 

Nothing wrong with cross rotation...I prefer it.
If for no other reason, it evens out toe-heel wear.

 

I’ve been bothered by a similar issue as well. And holy hell a new Ford GT just drove by me.... that thing was bad as shit. Anyway the truck wants to veer left on gas and to the right off gas. One shop said my rear right toe was .23 and everything else was fairly normal except my caster is 4.5-5 because I’m LT. Took it back to the shop who did the work and they took measurements, put it back on the laser rack and both outcomes said the toe was basically even at .14 both sides. Nevertheless the truck still exhibits the same characteristics and it feels as if the rear wants to swap to the right when driving it hard on rough terrain. For reference I am SUA. My only thoughts are the oem leaf hangars may be taking a beating.