Wheel Alignment 'Caster' is off

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The steering wheel should just be off center. There should be no pull if that's the only axis altered.

Side to side toe is a relatively new indication. Most vehicles just had so much static toe in (RWD) or near ZERO toe (fwd).

side note: Someone posted it here. The Crown Vic had static tow OUT. The only way I can see that working is if the scrub radius was way outboard. Even then, I'm not sure if it works in my head.
 
If the caster difference is off their will be a pull to the lower side if the toe is correct.If the toe is set perfect when u hold the wheel straight the car will pull to the lower caster side.
 
Caster is (or was) typically offset to one side. On a non-crown road it would produce a "drift" (to the left, iirc). A PULL is when you let go of the wheel (traveling straight) and releasing the wheel causes it to move in the direction of the pull.
 
The definition of pull varies from person to person. What u consider a drift someone can also consider a pull.
 
You're right. I tend to refer to a pull with some implied violence to it. The drift would be where you're driving down a non-crown road and needed to recenter the car in the lane every so often. It would do it hands on ..hands off ..a pull, would have the steering wheel moving when you released it.

Things change in 35+ years.
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FWIW, I agree with Gary- a pull is what happens when you let go of the wheel. Drift, to me, is when the car doesn't steer precicely. You have to keep making corrections to hold your line.
 
Originally Posted By: swalve
FWIW, I agree with Gary- a pull is what happens when you let go of the wheel. Drift, to me, is when the car doesn't steer precicely. You have to keep making corrections to hold your line.


That may be construed as wander

Drift and Pull are the SAME just when you delineate the change of term from one to the other changes with people. So only the degree of force having to hold the wheel to keep it going straight changes. Drift = minor Pull
 
Not really. When properly set up, caster is biased to one side. The wheel will center and the car, if you were on something like the Bonneville salt flats (for an extreme example), would complete a circle ..or a spiral. No movement of the wheel would be required. You could lock the wheel dead center and the circle would still occur. Not even the slightest of wheel movement is required for this to occur. Corrective steering is to return the car to the center of the road.

Biasing the wheel to account for the drift will result in moving in the other direction (the right). That is, there is no sensible corrective wheel position to remain on the road center.

This is antiquated knowledge here. 60's trapezoidal RWD stuff ..no rack and pinion ...etc...etc.. but the principle should still apply.

It accounts for road crown ...

..but we probably are dealing with semantics.
 
Originally Posted By: Gary Allan


It accounts for road crown ...

..but we probably are dealing with semantics.



I think SO.....

Road crown is accounted for sure and they are biased. Some cars are biased in the tires and require Self-Aligning Residual Torque Tires. With road crown on the Interstates now going both ways cars are being set more neutral so you do not induce a pull when in the fast lane due to reverse road crown.

As far as antiquated it all still works the same EXACT way today. Just the adjustment methods change. Heck the same stuff applies to Big Rigs too.
 
Originally Posted By: ewetho


Road crown is accounted for sure and they are biased. Some cars are biased in the tires and require Self-Aligning Residual Torque Tires.


Can you elaborate?
I've never heard of "Self-Aligning Residual Torque Tires"

Of the hundreds of cars I've aligned very few had offset CASTER.
Most will drift with road crown, but some designs are more forgiving than others.
 
Check the spec for something like a 65 Delta 88. Something before radial tires became OEM.

If your alignments have been done in the past 25 years, more often than not, it's a "set the toe, and let it go" scenario.
 
Originally Posted By: Gary Allan
Check the spec for something like a 65 Delta 88. Something before radial tires became OEM.

If your alignments have been done in the past 25 years, more often than not, it's a "set the toe, and let it go" scenario.


At least they charge you for a full alignment so you feel good about having taken care of your car.
 
Originally Posted By: Rabbler
Originally Posted By: ewetho


Road crown is accounted for sure and they are biased. Some cars are biased in the tires and require Self-Aligning Residual Torque Tires.


Can you elaborate?
I've never heard of "Self-Aligning Residual Torque Tires"

Of the hundreds of cars I've aligned very few had offset CASTER.
Most will drift with road crown, but some designs are more forgiving than others.


The tires have a diagonal tread pattern that causes just a bit of pull built into the tire. So both front tires have tread in the same way but one led with the inside edge one the outer edge.

They were standard on the last couple of years of Ford Minivans.
 
Originally Posted By: Gary Allan
Check the spec for something like a 65 Delta 88. Something before radial tires became OEM.

If your alignments have been done in the past 25 years, more often than not, it's a "set the toe, and let it go" scenario.


I'm not sure how to take that last remark but I'll let it slide...

As I mentioned earlier it was not uncommon to adjust caster (if possible) to a lower degree on the Left to off set road crown but often that wasn't the specification that was a judgment made by an experienced tech.
You are correct that most of my experience is on modern vehicles but even though there aren't factory adjustment for caster and camber on many cars anymore the spec doesn't allow for much (if any) of a difference of cross caster. If there is, something is bent.

I hope were not confining this discussion to just vintage Oldsmobiles or I'll have to dig out the service manual for my Cutlass convertible
wink.gif
 
Originally Posted By: ewetho
Originally Posted By: Rabbler
Originally Posted By: ewetho


Road crown is accounted for sure and they are biased. Some cars are biased in the tires and require Self-Aligning Residual Torque Tires.


Can you elaborate?
I've never heard of "Self-Aligning Residual Torque Tires"

Of the hundreds of cars I've aligned very few had offset CASTER.
Most will drift with road crown, but some designs are more forgiving than others.


The tires have a diagonal tread pattern that causes just a bit of pull built into the tire. So both front tires have tread in the same way but one led with the inside edge one the outer edge.

They were standard on the last couple of years of Ford Minivans.





So the RF tire had a different tread than the LF?
Got a link to the brand or model of these tires?
 
Quote:
I'm not sure how to take that last remark but I'll let it slide...


LOL.gif
No offense intended. You still need to check out the front end ..hang the mirrors...and typically your hands were tied for what you could adjust. It was usually down to setting the toe.

..but more than one tech would scan the tires ..see that nothing was out of whack..center the wheel..and "toe it in, and back it out"

I think the days of the tech knowing that his customer was 300lbs and having the tech put 100lbs of weight in the driver seat to assure that the alignment was correct ..are over.
 
Originally Posted By: swalve
Sure it will, if one wheel is more toe out than the other.


no it won't...you steering wheel will not be centered and exta tire wear will occur, but the car won't pull.
 
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