Caster?

[Ricosan]

B & S, it’s the steering box. I put the front end up on jack stands and vigorously shook the front wheels. The pitman arm would readily move back and forth an inch or so without movement of the steering wheel. I’ve had a lot of slop in the steering wheel since I got the car in January but I didn’t think that was the reason my steering would not self center after a turn. The car has recently been restored and all of the other steering components appear to be new. It has an f100 steering box that has been adjusted all the out (in). I have the kit to rebuild the box but haven’t yet found the courage to tackle a big job like that. I have a friend who has offered to help - still waiting.
Since all of the rest of the steering is tight, do you think I could get an accurate toe in measurement?

 

[glennpm]

When you get to rebuilding that F100 box, I just found this for you.

https://www.classicperform.com/tech_articles/TechFordSteeringBox.pdf

 

[cas3]

The steering box by itself has nothing to do with toe in settings. That would rely on good king pins and good tie rod ends to get an accurate setting

 

[ford38v8]

Ricosan, since the toe-in is independent of the steering box, I see no reason why that adjustment could not be made accurately, and your box rebuild be postponed in the meantime.

 

[Ricosan]

Thanks Glenn, that is perfect! I’ve printed it out so I can take it up to my garage. That is the rebuild kit that I have.
Richard

 

[1948F-1Pickup]

From your description of the issue you are experiencing, it sounds as if the toe-in is not correct. Not enough toe-in will hinder the front wheels from returning to forward position.
Positive caster will make it difficult to steer.

Nope. Doesn’t work like that.
Toe in settings are always minimized. They compensate for “road drag”….. that force created by driving down the road and the tendency to force the front tires apart toward being toed out while you’re driving down the road.
Not having crazy Toe out or Toe in is critical to combating what you sometimes hear referred to as “death shake/wobble.” (That and worn out or mis-adjusted steering boxes and steering components)
Positive caster is the setting that centers steering after a turn.
Your comment about positive caster making it difficult to steer is true, particularly if you crank it up to high numbers like 7 degrees.
My ‘48 truck is set at around 4…… that’s plenty.

I worked in the suspension industry for a number of years…..

 

[Tinker]

If you haven't installed new kingpins and all new joints. It probably doesn't matter toe in or out. Toe in is correct. But like everything here... Death wobble is usually caused by bad angles. Like drop axles without drop arms and loose joints. Toe in or toe out shouldn't make you fear driving.

 

[Randy in ca]

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Positive caster is the setting that centers steering after a turn.

Your comment about positive caster making it difficult to steer is true, particularly if you crank it up to high numbers like 7 degrees.

My ‘48 truck is set at around 4…… that’s plenty.

I worked in the suspension industry for a number of years…..

____________________________________________________________

Many vehicles (even without power steering) drive very well with caster of about 7 degrees.

If anyone is having trouble visualizing the effects that the caster setting can have on handling and stability, visualize riding a bicycle (or motorcycle) with neutral or negative caster:

-

 

[Ricosan]

Hey Guys,
I pulled a muscle in my lower back a couple of weeks ago and it’s gotten to the point that I am forced to back off from my work on my car for a week or two for some healing.

In the mean time here is a picture of my toe gauge that I made with one 2X4 lodgepole pine stud and a few scraps of wood. There is a screw on the right side that would go against the front of the rim about 9” up above the floor. The left end has a rule clamped to it.

It’s looks kind of crude but I believe I can get an accurate measurement with it.

Richard

 

[V8COOPMAN]

Hey Guys,
I pulled a muscle in my lower back a couple of weeks ago and it’s gotten to the point that I am forced to back off from my work on my car for a week or two for some healing.

In the mean time here is a picture of my toe gauge that I made with one 2X4 lodgepole pine stud and a few scraps of wood.

Richard

Richard.....You do some nice wood work there, but lifting that rig off of the work bench is probably what cranked your back out of whack! Besides, you're making this TOO complicated. May I re-suggest a very simple method shown in your OTHER thread on the same subject, which will likely give you a measurement of greater accuracy than your wooden back-buster can.


A good old fashioned plumb bob works. patiently and accurately hang it from the center of a tire TREAD in front of tire and mark the floor. Hang again from center of tire TREAD in back of that same tire and mark the floor. Make TINY DOTS using a sharp "SHARPIE".

REPEAT this same procedure on the opposite tire.

Now, you should have four dots on the floor. After moving the car rearward for easy access, measure the distance between the two FRONT dots.

Now, measure the distance between the two REAR dots.

COMPARE the two distances with each other. For example, you SHOULD have a FORWARD DOT measurement one eighth inch (1/8") LESS between the FORWARD DOTS than the REARWARD DOTS. This is what you are striving for IF you have a standard 1/8" TOE-IN. In other words, the front is TOWED-IN 1/8" as compared to the rear dimension.

If your measured dimensions do not equal 1/8" toe-in, adjust your TIE ROD until your measurements show 1/8" less between dots in FRONT, than between REAR dots.

Make any necessary adjustments to tie rod in small, careful increments.

Coop

.

 

[frnkeore]

Caster and king pin inclination are different but, work in the same way.

Both center the wheels by adding weight to the wheel, by lifting the chassis. The wheel will move back, because the weight pushes it back. In addition to that, KPI sets the center of the turning radius near the center of the tire contact patch.

You can use your tool for measuring caster, set the tires straight ahead, then mark 20° on the floor, to the front of both tires, turn the wheel, until it parallels that mark. Measure the camber, then turn the wheel the other way and again measure the camber. Add those two measurements together and that is your CASTER.

That's why alignment shops use turntables but, you can get very close with the above way.

 

[Ricosan]

Thanks Coop, I like it. I’m going to use your method as well as my tool and hopefully We will get the same measurement.

My back still has me out of service. Therapy this afternoon.

Thanks Frank, as soon as I can get back to my garage, I am going to use your method and compare to the figures I got the first time I measured it without scribing the 20 degree mark.

Richard

 

[alchemy]

Not sure if was mentioned, I'll admit I didn't read every word of the replies. When you are measuring the center of the tires, front and back, you need to make sure you are actually using the centerline. Don't trust the tread grooves. Jack the wheel up and spin it, and tightly hold a fine sharpie marker to the tire as it goes around. Make sure you can brace your hand against the bumper so you don't waver. Then use your good line to measure from.

 

[cas3]

Totally agree with alchemy ^^^, I like to wrap the tire with masking tape so the marker pen doesn't bump around on the tire treads, and makes an easy to see fine line. If you move or goof up the line, tear it off and do again. easy-peasy