Rear Alignment toe, fixing thrust angle, what can you do?

Appreciated!

Wow That makes a lot of sense! I think it wise now to inspect. With two blown cam bolts in the front, from November, something could have easily gone wrong back there too!

Thanks!

 

Shane had a similar issue and had ended up bending the axle I dont remember his username though lol Dark red taco that had rolled and did the self recovery with a winch.

 

Tahnks Chris!

Oh yeah, that was back in 2014, his username is @Mach375

Found this quote in the forum from him

 

Hope it helped!

 

You can adjust thrust using this sandwich plate, however it will change ride height on one side. I suppose you could install two...

 

So this isn't that much of a concern other than the steering wheel being off center?

I just got my alignment done, after taking a good beating at Gulches ORV park last weekend. The numbers look good so I figured that it was because I drove 4.5hrs on a really bad alignment.

 

Yes. Thrust angle is nothing to worry about, IMO. It's a fundamental angle that the shop has to calculate before aligning the front.

Looking at your sheet, your toe was really out!

I don't know if you have plans Tim, but I do recommend welding reinforcements behind the alignment cam tabs, or burning on some of the TC weld on ones. Since I've done that, they've always held the cams firm

I did mange to blow out some cams after that though.

 

Yup, that ORV park was a lot rougher, as far as main roads go, than other parks I've been to. I already have the factory tabs tacked. Thanks for the tips though. I'm not sure what moved, the numbers weren't good to begin with (Firestone halfass attempt at an alignment).

 

Thread revival time!
I had the same thrust angle as yours and it was bugging me for a long time.

During the addition of rear shims to rotate the diff a little in attempt to address drive line angles and the dreaded takeoff shudders I noticed that the diameter of the locating pin through my leaf springs was less than the locating hole in the spring mounting perch.
I did some calculations as to what it would take to to get the axle back to zero thrust angle and very slightly enlarged the mounting holes on the perch with a Dremel a bit oblong to the rear on the right side and to the front on the left so the right-left position of the axle would not change. It did not take much.

I then took two ratchet straps mounted to the axle and pulled the right side forward
and the left side rearward -- thus slightly rotating the axle counter clockwise. And the tightened the ubolts with the straps still under tension. The springs have to be relaxed doing this and use jack stands under axle.
Depending on the alignment machine used my thrust angle came down from 0.30 deg. to around 0.05 deg or 0 degrees.

Just an observation about thrust angles. The thrust angle is controlled by the position of both rear wheels. It is the average angle (toe) that the wheels point away from the geometric center line.

Both my Tacos came from the factory with about 0.30 degrees of rear thrust, all toward the right. Many such thrust angles are corrected during an alignment so that all 4 wheels then track the same. The thrust angle is still there, but unless it is very severe, you will generally not notice because the steering wheel is straight. This is done placing the steering wheel straight then anchoring it and then by changing the toe of both front wheels to match the thrust line instead of the geometric center line of the vehicle.

 

If your rear axle moved on its own something's broke. There's a nipple where the leafs sit to align them, the nipple might be gone or the hole is wallered out. Or a bent frame

 

Thanks for your input. As discussed in this thread and mentioned in the last post there is room for the nipple you reference to move. I have a brand new frame which toyota installed and it has the same issue. Not a serious issue because it's such a small amount a simple 4 wheel alignment will negate the effects of this.

 

My truck has the same issue. I recently purchased it brand new. I've had it aligned at the dealer once already and they say it's it's within specs. The steering wheel is still off, but to keep it straight you have to keep going left and right on the steering wheel. I'll provide the spec sheet that they gave me after they did the alignment. I've tried to contact them again to let them know something's not right. It's not fun to drive when you're constantly holding the steering wheel and it's always pulling left and right. Any thoughts on how to approach the dealer to get get this resolved? I only have 600 miles on the truck.

 

Ha, good luck with the stealer as they are going to tell you its within specs, although ToyMoCo does not publish what those specs and tolerances are. If it makes you feel any better I have yet to see a rear axle on the Tacoma that is square to the frame, even new and for some reason most seem o have a positive thrust angle. There are two reasons for this: their jig used to build frames has a +/- range, and if it is anything like their front wheel specs it is quite broad; and the second being measurement errors of the alignment equipment.

By convention when the rear wheels point to the right of the vehicle center line it creates a thrust angle that is positive and negative thrust angle if toward the left of the center line. Your sheet shows a positive thrust angle 0.20 degree. Both my Tacomas came with about 0.30 degree. This can easily be corrected for by doing a thrust alignment where the front toe is adjusted using the thrust line and not the vehicle center line.

 

.......oh, and there is no reason that your steering wheel needs to be off center unless it has smacked something or the suspension has been modified.

If you have stock suspension and no hits, the problem is the alignment technician, machine that is not calibrated, or bad tires. The steering wheel being off points to the tech or equipment. Take it back or to that dealer or another and tell them it is unacceptable and have them run the diagnostic angles SAI (steering axis inclination) and IA (included angle) to rule out bent parts. Be aware that getting poor alignments is a very common problem and you may have to try several other places, preferably one that specializes in alignments. Be persistent.

 

Thanks guys and gals (don't wanna leave anyone out!), appreciate it. I talked to a friend that owns a body shop here locally (I live in a small town - dealer I bought it from is over an hour away). He indicated the same info you guys have conveyed and gave me a place to go take it to that's not solely going to rely on the machine but knows how to do an alignment. He said they'll figured out if something is actually wrong or can align it correctly so it's not having the issues that I'm having. If they can correct the wobbling of having to keep it straight and fix the steering wheel alignment I'll be extremely excited. Thanks for the info guys!

 

So after I wrote this post, I noticed on my toll tag account the truck had been charged for tolls that weren't mine. Turns out the saleman who delivered my truck ran through multiple tolls when bringing it to my house. htat just set me off to no end. I've emailed him a couple times trying to get a response on dealing with the driving issue of the truck. So I have his personal cell and sent him a text letting him know how disappointed and upset I am with the whole issue. He called me, and asked what I wanted. So I told him I want the truck fixed properly now or I want my Lexus back that I traded in for the truck. Said he'll talk to the manager of the dealership and get back with me. Who knows where it'll actually go from here, but good lord it's disappointing.