Toe Alignment Inches To Degree Conversion

-
Ricks70Duster340

Ricks70Duster340

Child of the King
FABO Gold Member
Joined
Feb 8, 2021
Messages
1,277
Reaction score
1,002
Location
Sisterdale, TX
The alignment shop uses degrees in their software for toe instead of inches. What should the 1/16" to 1/8" toe be in degrees?

Edit: And should the settings be the same side to side?
 
If the default setting of the tire diameter is set to 28.648 which most machines are I think, the calculation is 2 degrees equals 1 inch.
The exact measurement would require the tire diameter and a scientific calculator and some math that I have no answer to. And yes toe can be measured individually when referenced from the thrust angle. Mind you, toe always divides under a dynamic condition.
 
Ricks70Duster340 said:
The alignment shop uses degrees in their software for toe instead of inches. What should the 1/16" to 1/8" toe be in degrees?

Edit: And should the settings be the same side to side?
Click to expand...
Just tell the shop to use inches instead of degrees. All it takes is mashing one button.
 
Bodyperson said:
If the default setting of the tire diameter is set to 28.648 which most machines are I think, the calculation is 2 degrees equals 1 inch.
The exact measurement would require the tire diameter and a scientific calculator and some math that I have no answer to. And yes toe can be measured individually when referenced from the thrust angle. Mind you, toe always divides under a dynamic condition.
Click to expand...

Yup, this.
mopowers said:
There are lots of online conversion calculators available for this.
Click to expand...

Yup, this too. As above, a good online conversion needs to have the tire diameter as part of the conversion if it’s to be accurate at all.
 
If you have it on an alignment machine the steering wheel is centered and locked. Toe is adjusted on each side to equal the spec total. One side may have to be adjusted more or less than the other but it is all about correcting the toe spec and making the steering wheel straight. It has nothing to do with adjusting both sides equally.
 
Last edited:
toolmanmike said:
If you have it on an alignment machine the steering wheel is centered and locked. Toe is adjusted on each side to equal the spec total. One side may have to be adjusted more or less than the other but it is all about correcting the toe spec and making the steering wheel straight. It has nothing to do with adjusting both sides equally.
Click to expand...

That’s not entirely true though. These cars have an equal length tie rod set up, so, if the steering gear is centered then the tie rod lengths should be relatively close to equal, or at least within the factory tolerances anyway.

Not all of the aftermarket steering wheels are set up with a master spline, so having the steering wheel straight might not reflect the steering gear being centered. Which means you wouldn’t get the same turning radius left and right.

The total toe should be split evenly between each side, and on these cars at least that should mean the adjustment is fairly close too, unless something is bent, which is a whole different issue.
 
72bluNblu said:
That’s not entirely true though. These cars have an equal length tie rod set up, so, if the steering gear is centered then the tie rod lengths should be relatively close to equal, or at least within the factory tolerances anyway.

Not all of the aftermarket steering wheels are set up with a master spline, so having the steering wheel straight might not reflect the steering gear being centered. Which means you wouldn’t get the same turning radius left and right.

The total toe should be split evenly between each side, and on these cars at least that should mean the adjustment is fairly close too, unless something is bent, which is a whole different issue.
Click to expand...
It also means if you have power steering and the gear box isn't in the center, but the steering wheel is, you might get a pull since the gear box tries to find center when it is energized.
 
My original question about the readings being the same side to side was referring to the alignment printout that showed the numbers on each side. When I got this car, the alignment sheet was part of the paperwork I got. The caster was off (and it did not feel good at above about 70). The toe was different side to side, so that was my question. Sorry for not relaying that earlier.

Alignment.jpg
 
Inverse sine of the half the toe (opposite side) over the wheel diameter (hypotenuse). So assume we want 1/8" total toe, that's 1/16" or .0625 per side. And assuming a 26" tire, Inv SIN .0625/26.00 =.138 degrees per side. As for being the same side to side, in an ideal world yes, but they're adjustable for a reason. A good alignment will split the toe about the a line perpendicular to and centered on the rear axle with the steering gearbox (not necessarily the wheel centered). This is sometimes called a "thrust angle alignment." This is also what you get if you just use strings and jack stands and set the strings off the back wheels. Hopefully, the body centerline is pretty close to the rear axle centerline, but you are concerned about what direction the wheels point and not the body. In your printout above, the rotational axis of the front wheels is not parallel to the axis of the rear wheels. Teh right rear is slightly behind the left rear. And you should be able to get more caster even with factory parts.
 
Last edited:
You must log in or register to reply here.
-

Back
Top