4 Wheel Alignment or Front End Alignment?
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The angle is determined by where ever the toe is set at. You want the toe tipped in at the front, centered, edge of the tire. This means the distance between the front edge of the tires measured laterally across both front tires is shorter than that of the rear, centered edge of the front tires. I would set the toe at the minimum spec of .20" left and right. The angle will be whatever the toe is set at and really isn't a factor other than to show what the angle is at the toe setting.
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Joined: Aug 2020
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The angle is determined by where ever the toe is set at. You want the toe tipped in at the front, centered, edge of the tire. This means the distance between the front edge of the tires measured laterally across both front tires is shorter than that of the rear, centered edge of the front tires. I would set the toe at the minimum spec of .20" left and right. The angle will be whatever the toe is set at and really isn't a factor other than to show what the angle is at the toe setting.
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From: Kentucky
Tow is how parallel the tires are to each other. The forward edge of the front wheels pointing towards each other is positive tow, or tow in, the front of the tires pointing away from each other is negative tow, or tow out. Spec for the F150 is 0.0 to +0.2º of tow each side, or a total of +0.4º of tow.
These tow angles can be set with the steering wheel turned wherever. You can have the wheel turned all the way to the right and set these two specifications, but when you turn the wheel back to center, the wheels will be pointing way off to the left. The tech must center the steering wheel before aligning, and check periodically during the alignment.
Thrust angle... if the rear axle thrust is well off, the steering wheel will appear to be not centered. Looking at those alignment results, a positive thrust angle will cause a vehicle to curve left, requiring a correction by steering right. However, spec for the trucks is 0.3º thrust to account for driving in the right lane on highways, which slopes to the right. I'm not sure that being 0.2º over is enough to make the steering wheel appear off, but I've not had to deal with that.
If this matches your situation, you need to measure setback, the distance between the front and rear wheels, and the height of the frame at the rear wheels. Bent frames and weak leaf springs can both change thrust angles.
These tow angles can be set with the steering wheel turned wherever. You can have the wheel turned all the way to the right and set these two specifications, but when you turn the wheel back to center, the wheels will be pointing way off to the left. The tech must center the steering wheel before aligning, and check periodically during the alignment.
Thrust angle... if the rear axle thrust is well off, the steering wheel will appear to be not centered. Looking at those alignment results, a positive thrust angle will cause a vehicle to curve left, requiring a correction by steering right. However, spec for the trucks is 0.3º thrust to account for driving in the right lane on highways, which slopes to the right. I'm not sure that being 0.2º over is enough to make the steering wheel appear off, but I've not had to deal with that.
If this matches your situation, you need to measure setback, the distance between the front and rear wheels, and the height of the frame at the rear wheels. Bent frames and weak leaf springs can both change thrust angles.
Last edited by Flamingtaco; Aug 21, 2020 at 07:50 PM.
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Joined: Aug 2020
Posts: 62
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Tow is how parallel the tires are to each other. The forward edge of the front wheels pointing towards each other is positive tow, or tow in, the front of the tires pointing away from each other is negative tow, or tow out. Spec for the F150 is 0.0 to +0.2º of tow each side, or a total of +0.4º of tow.
These tow angles can be set with the steering wheel... wherever. You can have the wheel turned all the way to the right and set these two specifications, but when you turn the wheel back to center, the wheels will be pointing way off to the left. The tech must center the steering wheel before aligning, and check periodically during the alignment.
Thrust angle... if the rear axle thrust is well off, the steering wheel will not *appear* to be centered. Looking at those alignment results, a positive thrust angle will cause a vehicle to curve left, requiring a correction by steering right. However, spec for the trucks is 0.3º thrust to account for driving in the right lane on highways, which slopes to the right. I'm not sure that being 0.2º over is enough to make the steering wheel appear off, but I've not had to deal with that.
If this matches your situation, you need to measure setback, the distance between the front and rear wheels, and the height of the frame at the rear wheels. Bent frames and weak leaf springs can both change thrust angles.
These tow angles can be set with the steering wheel... wherever. You can have the wheel turned all the way to the right and set these two specifications, but when you turn the wheel back to center, the wheels will be pointing way off to the left. The tech must center the steering wheel before aligning, and check periodically during the alignment.
Thrust angle... if the rear axle thrust is well off, the steering wheel will not *appear* to be centered. Looking at those alignment results, a positive thrust angle will cause a vehicle to curve left, requiring a correction by steering right. However, spec for the trucks is 0.3º thrust to account for driving in the right lane on highways, which slopes to the right. I'm not sure that being 0.2º over is enough to make the steering wheel appear off, but I've not had to deal with that.
If this matches your situation, you need to measure setback, the distance between the front and rear wheels, and the height of the frame at the rear wheels. Bent frames and weak leaf springs can both change thrust angles.
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Joined: Aug 2020
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Keep in mind, that rear thrust angle is just 7/10's of a degree. I question the ability of many alignment machines to measure that accurately to a tenth. Most look like they've had two or three three decades in the shop. When was the last calibration done?
Any alignment tech worth his/her salt will wipe down the wheels and check for high spots due to impact before mounting the sensors. Most aren't worth my shaker of table salt. That 0.2º difference between readings comes out to 1.5mm difference between where the sensor mounts on opposite sides of an 18" rim. That's well within the tolerance of a nice whack against aluminum with a hard object, or the tech not ensuring the sensor was fully seated.
Any alignment tech worth his/her salt will wipe down the wheels and check for high spots due to impact before mounting the sensors. Most aren't worth my shaker of table salt. That 0.2º difference between readings comes out to 1.5mm difference between where the sensor mounts on opposite sides of an 18" rim. That's well within the tolerance of a nice whack against aluminum with a hard object, or the tech not ensuring the sensor was fully seated.
Last alignment im doing, and now the steering is centered when going straight and a lil compensation on road crown and if i let go sometimes a lil pull to the right
5 Year Member
Joined: Aug 2018
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From: Kentucky
Yes. Toe and camber affect tire wear, caster affects steering pump/electric motor wear, although it's not significant unless well out of spec. If holding the wheel in position on the highway isn't a chore after an hour of driving, you're golden.
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Joined: Aug 2020
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so is toe and camber good rn? And on some roads i gotta hold it but because they are crown roads,