'dog walkin'
 

ok, this is random as ****. We are having an argument here at work and I want to see what you all think..

Its about 'dog walking'.. you know, sometimes you see the truck going down the road that isnt actually going straight and you can see the side of the truck? Bacailly, the argument is if you dont but the axle exactly on straight and the truck goes sideways, does it mess up your tires on the rear axle?

I dont think it will, because you are going to have to turn the steering wheel to make the truck track straight, so I dont think it really will hurt the tires.

I disagree. I say it chews up tires. And thats with no valid argument or evidence to prove it.

its really putting a strain on all 4 if you ask me

your alignment is out. tires will suffer. period.

How is this an argument? Of course it will eat tires

how though?

either way, the rear tires are still pointed straight. your steering wheel is now turned. I dont understand how it will eat the rear tires up.


I always think about the monster truck with 4 wheel steering, one way they turn opposite of each other and you will turn harder, but if you make them turn exactly the same, it will make the truck's body turn but still go straight down the road

let me throw a theory out there, because i deifnitely see both sides of it. even if they are tracking straight, with the body crooked, there will still be some sideways component to pull the wheels at a sideways angle.

or let me restate. the back wheels are pushing straight forward. the force goes forward, but is at an angle to the body, which pushes the truck to one side. perhaps i will make a diagram...
i think its more complicated than people think, but yes I believe it wears on the tires.

I'm confused, is the axle perpendicular to the frame? If it isn't then you're going to eat your u joints because the driveshaft will turn on 2 axes.

im talking about very minimal amount. the stuff you sometime see driving down the road. just enough that you can tell its not really going down straight.

offset Toe angle?

If it's minimal and the rear tires are still going straight, then you won't do immediate damage, but it's something that should get fixed.

ok here. I made a diagram. black shows the force forward from the rear tire. there is a component (orange) parallel to frame. regardless of which direction you turn the front wheels, there is an overall forward force parallel to frame. anytime the wheels are turned there is extra strain. which is why tires wear more when turning. so basically, and offset axle is like being able to put the stresses of a turn on your truck while going in a straight line.

http://i150.photobucket.com/albums/s...asic-force.png

That is actually something I was thinking about when I did my 8.8 swap.

:popcorn:

i can def see both sides. also didnt even think about the ujoints

U-joints are never in perfect alignment so unless it is extreme I don't think it would matter.

Personally I think the rear tires would not wear any faster but I think that the front tires would wear faster from constantly turning.

long term your gonna have damage, and part of that damage is gonna be your tires

We have Ford E150 -250 vans at work and they all do this. Ford vans are well known to dog track. All of our vans have close to 400,000 miles on them and we have never really noticed any more wear on the tires than normal, they are rotated regularly.

The way I remember this:

If you're aligned well (thrust angle) and have all tires running in the same direction (with steering at the wheel / rack / pitman = centered) then you'll be largely OK while traveling straight -- if you're "steering" to maintain the dog-tracking then you'll be introducing the Ackerman angle (that's the ratio that related the inside and outside steering of the front wheels the operating angle of the steering arms coupled with the angle to the tie-rods determine the differential steering applied to each wheel -- outside wheel travels in a wider arc when turning)...

Anyway -- if the thrust angle alignment is spot-on -- all should be right with the world for going straight, however, since the tie-rod and steering arm angles are affected (by aligning to address the dog-track) turns become a new devil and should likely result in accelerated front tire wear. The introduced Ackerman angles become non-symetrical about the "modified" centerline / direction of travel ... In the illustration above the "right" front steering would be more sensative to steering input, which may be fun for right turns but could 'push like hell' for a left turn...

we have a couple buses at work that do this. i saw one the other day and it was bad. i was like WTF!?!?! a brand new hybrid dog walking...?

I agree that it will burn through 1 front tire quicker than the other because of the ackerman as stated above.

For most people with this issue, it wont cause uneven wear, some people who offroad or are rougher on their trucks may have more extreme conditions of course. Rangers have really squirrelly rear ends and over time, going over bumps hard, offroading and such, this dog walk will happen. I beleive the phenomenon of it happening over bumps and such is called thrust angle, thats how you measure the degree of the angle the rear is off by. (0 degrees is perfectly straight in front of one another)

. For example, my truck has a thrust angle of about 20 degrees, just from the design of the rear end and years of driving(i hardly ever am "off road") it exhibits this difference or "dog walk". my alignment is dead on, as is my tire wear and my steering wheel is dead center when i drive and it doesnt swurve or anything. the trucks axle is still perpendicular to the direction your driving, its just slightly diagonally shifted to one side.

i hope this helps, its kind of hard to articulate effectively, i would never be a good teacher lol.

We just covered this at school over the past 2 weeks. Basically you will not have wear issues on your rear tires, the rear axle will still go straight. You are going to turn the steering wheel to keep the truck going straight. And in result you will have feathering on your front tires. At first you are going to think you have a bad toe problem but the tell tale sign is that one tire will have feathering on the inner edge of the tire and the other tire will have feathering on the outer edge of the tire. Now if you only have feathering on one tire and the other tire is wearing normal, it means you have a toe issue on one tire and "Dog Tracking" issue in the rear. I don't have my books on me right now or I would scan the diagrams that shows all of this.

great info. thanks!

i go to a technical school and im a mechanic/technician at pep boys. dog tracking will cause tire wear. its like being out of adjustment on your toe in the frot end. the tires are angled and are forced to go straight. which will give them a feathered wear pattern.