Semi tractor toe in

Question for those of you who know more about wheel alignment on a semi than I do. What's the toe in measurement on the steer tires and where do you measure it on the tire? Son's truck was wearing the edges of the steer tires so he took it to a larger tire store for an alignment. It drove slightly better but he was still wearing the edges off. There is no cupping, just even wear. Replaced the tie rod ends last Saturday, they weren't too bad, but he did it anyway and he had to heat the tie rod to get the ends to screw out so obviously the tire shop hadn't done anything to the toe-in. The truck is a 9400 International and the tires are Goodyears.

I set mine between 1/16" and 1/8" toe in and measure right at the bottom of the leaf springs. Have no idea if this is the recommended way, but my last set of steer tires had 120,000 when I pulled them and still had plenty of tread to run out in a trailer position.

Rick(MN)"s comment about toe in is the same way I set mine.
But what you said about the wear makes me wonder if maybe the king pin bushings are worn out.
Caster and camber must also be correct.
Another thing would be to call the service department of an 18 wheeler truck center and ask if they do alignment or who do they recommend in your area.

I can't tell you the spec because I don't know... but I do know that you can get a computer alignment done the same as a car. No idea on cost but I suspect it's far less than a set of steers. Problem could be in the back end as well rather than the front depending on how it's wearing... so I'd suggest going to a heavy truck shop if he feels the problem is serious enough in terms of tire wear.

Rod

I think he's going to end up taking it to a large truck alignment place. There's a place 150 miles away in Sioux falls that the local truckers swear by that he's considering. We did set it to about 3/8 just under the springs but it sounds like that's a bit much. While the threads are clean it wouldn't take long to give it a couple of twists. We have thought about the king pins too. When he bought the truck it had just a twitch over a million miles on it and he's put on around 200,000 more since then. It's a really nice truck for the miles it has. He got lucky for no more than he paid for it. Jim

(reply to post at 16:37:40 12/04/10)

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used to do that for a living It was 1-8 to 1-16 of an inch .

hello we mark a spot on both tire next to the rim or on the rim lip it s self roll it to the rear take a reading no roll it to the front and do the same then we adj. the toe to a 1/8 wide in the front and that works wqell for us as we do a lot of off road and heavy work carrying plow and wing i hope this helps jim

ps sorry if they r radiels they will wear like till shot sorry jim

(reply to post at 17:49:43 12/04/10)

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Mark the center of your tread by jacking it up and spining the tire .Then take sharp object and mark the center of the tire while it is spining .Then let the truck down and measure the front and rear about one foot up from the bottom in should be 1-8 to 1-16 toe in the front of the tire being closer than the rear .Used to work for trucking co. doing this .

When I had my truck I did as Rick(MN) said. I used to check the king pins by jacking up the front axle under the spring then grab the tire at the top with one hand and bottom of the tire with the other and see if you can get any slop by pushing the top in and pulling the bottom out. as far as marks to measure the toe in by, I would jack up the front end and spin the tire then lay a screw driver on the face of the tire part with solid rubber, scribbing a line on both tires. Them let the jack down and get the weight back on the front tires, then adjust the toe in.

3/8 toe in and the tires won t make it to the alignment shop. Caster will not wear tires but worn out king pins (camber) can and will let the toe change every time you hit a bump.

If your alignment shop doesn't start at the rear of the truck and work to the front, find a new alignment shop. No amount of caster and camber adjustment can fix a thrust angle problem. Loy (30 year truck mechanic)

I took my 379 pete to alignment shop for edge wear like you are explaining said problem was brand of tire due to slant of road had firestones on

Thanks for the info. We weren't sure where to measure from on the wheel itself. It makes a big difference on a wheel that size. I do know most of the time an alignment involves only the rear axles and nothing needs to be done to the front if the kingpins are within specs. Some truckers claim it's not possible to do a good computer alignment on a truck. Whether it's folklore or not, I don't know. Tomorrow we're going to mess around with the toe in to get it to 1/6-1/8. We'll have to wiggle the tires to see how the kingpins feel and go from there. Jim

Toe is the last adjustment you should make. If the camber is negative then it requires a negative toe. Do everything else first.

To set toe-in you raise both front tires off the ground just enough so they spin freely. Now spin the tire real good and use a sharp pointed instrument to mark a ring around the tread of the tire, this gives you a true spot to measure from. Next set it back down on a smooth even floor not out in the dirt. Now measure both front and rear to see what the toe in is. find out what the manufacture recommends and set it to that. 3/8 seems an awful lot, most big trucks are 0 or just a small amount like 1/16. To check the spindles raise the wheel off ground and use a long bar to lift it up and down watch for movement in spindle not wheel bearings.
Walt

Hello Fixerupper,
Walt Davis is right! 3/8 toe-in 0r 0ut is too much.
Radial tires will wear best at zero to in.
If they are wearing on the outside on both tires, you have too much toe-in in most applications.
If only one is wearing on the outside, then it is either camber or top king pin bushing is worn out. When the bottom king pin bushing is worn out, the inside of the tire will wear out.
Cupping is caused by a bad shock or low air pressure.
Guido.

I think when you have just replaced the tie rod ends the first place to start is getting those new ends set where they belong, if he had just not changed them it would be different.

I was a mechanic for RUAN the truck leasing company in the 1980s for 3 years.We would take a scribe like thing we made which was a 3/8 rod sharpened on one end welded to a cheap jack stand.The you jack up the front end where its just off of the floor,put jack stands under it so its level,Check for slop in the king pins by prying on the wheel herd with a tire tool and if it moves you have to put king pins and bushings in first.Then take a can of white paint,Paint the center of the tire.Usually there is a rib right in the center,so paint the center rib,spin the front tire good,and as someone spins it,another guy pushes the scribe in to the center of the tire and makes a mark all the way around the tire,just one mark,right in the center,if you mess it up,repaint the center and do it again,its not hard after you get the hang of it you can do it by yourself.Its real easy to see with the white paint and the black tire,with a groove cut through the white paint.Then with a tape measure you measure between the frame and the front and back of the tire,to the scribed line, and get it exactly the same on one side,usually the drivers side because the right side of the road is rougher and the right side wears more,and probably is the side thats off.So you get the drivers side straight,then measure the other side.Either the front will be farther away from the frame,or the back.99% of the time it will be the front side is out farther from the frame.So then you measure from the groove in the white paint you made on the front of the tire,and then measure on the back of the tire,across both tires,you need a helper to hold the tape exactly in the groove,at the same place,in the same spot on the front, and back of the tire as close to half way around as you can.Then see how much difference you have,say you have 1/4 inch out at the front.You loosen up and take out your pinch bolts on the tie rod,clean the exposed threads with a wire brush,shoot with a lot of penetrating oil,and put a big pipe wrench on the tie rod and turn it.This sounds easier than it is.Once in a while we would have to put a floor jack on a pipe wrench to break it loose.Once you break it loose it turns easy.Heat would be a last resort.I dont remember ever heating one to be honest.Then you give it 1/16th of an inch toe in,on the front.As you adjust the tie rod you have to keep the drivers side tire at the same distance front and back,from the frame, then measure the other side.Once you get them straight you want the front just a little tighter than the back,like 1/16th of an inch.
The more accurate you can measure the better off you are,and the better of a job your helper does at getting the tape in the exact same place the more accurate of a job you can do.Set it back down and measure it again across the tires front and back.If its close,like less than 1/8th inch or the same, it will probably do alright.If its not close,the spring shackles,spring eyelets, are probably wore out and you need to replace them too.

Ive worked on a lot of Internationals,mostly cabovers.Some of them are alright,some of them you cant keep steer tires on.Especially setback front axles that carry a lot of weight on the steers.I dont remember what the exact year was but I think it was in 1991,they used a front axle that the wheel bearings wore out about the same time the steer tires did,way before 100,000 miles, on the setback cabovers.

If you do it like I said,provided I wrote it clear enough that you understood,and if you replace what needs replacing,the amount you save in not wearing your steer tires out every 50 to 75,000 miles, will pay for the other parts easy.You need to check them about every other time you change the oil.And keep the toe in at 1/16 or straight when its setting there on the level concrete floor.Once you jack it up if it changes a lot you have other work to do first before you can align it.Also when you get done,and take it for a test drive,your steering wheel should be straight as go down the road.Maybe just a little off if the road is crowned up in the middle,but not much.If nobody had the steering wheel off,it will be straight or real close to it,as long as the steering box is not wore out,and you will know you did a good job.
Internationals are not KWs or Peterbuilts.You have to replace stuff more often,but you can make them work if you stay after them.Plus they are probably as good or better than Freightliners and Volvos.Volvos didnt get the miles out of steer tires that Internationals heavily maintained would.

I almost forgot a very important part of this.Once you get the steer axle set while you have it up and straight as you can get it,you measure from the steer axle to the centor of the front drive axle.There will be shimse you can take out or put in to get both sides the same,and then you move to the rear axle and measure it from the front drive axle.All of these measurements have to be as axactly the same as you can get them.Sometimes you may not have a problem with the steer axle at all,it may be set,but somewhere on the back some bushings are shot and it keeps pulling the truck to one side or the other,and that will wear out steers and drives too.Doing an alignment is a lot more than just turning the tie rod usually.Bushings and stuff wear out on the back,just as bad as the front,maybe worse.
All the trucks I had,every one had to have back bushings,only one needed king pins on the steer.I got 100,000 miles and more out of steer axle tires and all of mine were setbacks.They were all KWs but that just goes to show that they wear out too.Actually my newer KWs were worse than may older Kw was about those back bushings.

I could never get a lot of miles out of Firestone steer tires.BF Goodrich are a lot better in my opinion.Actually BF Goodrich are owned by Michelin and some of the steer tires look like the old Michelens that would get over 100,000 miles.Some people like Bridgestone.I like Michelen and BF Goodrich.Firestone has had some problems,I cant remember now what it was,but if you want tires that will last I think Michelen and Bridgestone,the BF Goodrich,and now there are others that look like BF Goodrich with different names.That kind of says those old Michelen tread patterns worked good since so many are copying them.I dont know a lot about Bridgestones.Ive had some and they lasted,but I cant think of any steer axle tires that I had that were Bridgestones.I had some other steer tires that out did Firestones,sold by a Firestone dealer,I think they were Continental or something like that.

I had my truck aligned with a computer alignment place a couple of times and I think that as long as the guy doing it knows what he is doing,and does a good job,you can do great,much better than with a tape measure.If he is sloppy and doesnt have a lot of experience and know what to look for,you could be disappointed.
Actually most stuff that I had done on my truck at a shop was not very good workmanship.Being a mechanic for 10 or 12 years myself,I know what good workmanship is,and usually stood and watched what they did unless I was dead tired.I have a cousin who works at a truck shop,and the stuff he did was good,the best I got in most cases.But that is kind of a rare thing.Some guys are real good at what they do,but he may work on your truck once and the next time they have the floor sweeper working on it and he makes it worse.Its kind of a tossup.Id like to see his work and hear what the customers say about him.But actually with a good mechanic doing the job,and knows the equipment,he should be able to get it right on the money with a laser.Should and what actually happens in real life might be far from reality.If you can trust them,they can do a good job.

I agree... it's not hard for them to screw something up either. I've nver had one aligned myself because I don't have any tire issues... but I do know one real good guy to take it too if I did. No hesitation at all.
The main point of what I was getting to is that the problem could be at the rear... either at the radius rods on an air ride or single axle or the beam bushings on a hendrickson system... regardless the axle(s) may not be perpendicular to the frame causeing a push to one side. That would probably be easier to catch with the lasers... but as you say... correcting it properly will require a pretty sharp mechanic.

Rod

Thats true about the back bushings wearing tires.Grip treads are about 400 each where I am here.Bushings for my air ride KW were about 50 dollars a piece and usually only needed 2 to get it lined up.That 100 dollars worth of plastic bushings,then set with a laser,would last a couple of years of running usually.With high dollar tires,you want it lined up by a competant mechanic.Over a couple years time you might save enough to buy a new set of tires by keeping it lined up.Also it makes driving the truck a lot easier instead of fighting the wheel all the time and wearing the tires out too.