The Stovebolt Site Forums The Shop Area General Truck Talk Front End Alignment

I am in the process of peeling the tread off the inside of my front tires. My shop manual tells it is most likely a toe -in issue, but my question is: With the original front end , why does one tire, the drivers side, wear more severely than the other? It would seem both should wear the same, unless it is a camber problem. The book says, however in this case, the wear should be on the outside.

Thooughts?

Both should wear on the inside, but I have see just one like yours is doing. Its easy enough to check toe end.
First, scribe a line around the center of the tire using a sharp pick.
Next roll the truck forward on a level surface so the tires make at least one to two full revolutions, let it come to a stop with out using the brakes.
Third, measure the rear of the tires as high up on the tread as you can with out hitting the bottom anything like exhaust or transmission.
Forth, move to the front and measure from the same hight. Subtract the front from the rear and you should have you toe end. You are looking for 1/16" to 1/8" toe-in.
If the steering is worn out you need to fix it before working on the tierod adjustment.

Joe

Thanks Joe, I'll give it a look.

Check for a bent tie rod. That will cause the toe to be out also. The reason one is wearing more than the ohter is that you are copensating for the toe being out along with compensating for road crown when you drive. That puts more stress on the left tire on a straight axle. Joe's method is a good one to follow to get a baseline toe setting. You will want ot make sure that the tie rod ends and the drag link ends are adjusted properly, along with the steering box itself.

Take it to an alignment shop and spend the $50 to get it aligned or at least diagnosed. You can rarely tell by just eyeballing as to what's actually wrong.
Just my 2 cents,
Scott

Thanks for all the comments. All good. I will most likely take your advice Scott. I have to replace the tires now, so I might as well have a shop set the toe in.

Too much toe-out will wear both tires on the inside. Too much toe-in (pigeon-toed) will wear both tires on the outside edges.

Zero toe (pointed straight)gives you good even wear. A little bit of toe-in keeps the vehicle from wandering around over irregular road surfaces at speed (hence normal settings are for a bit of it). A little bit of toe-out gives you better turn-in (typically a racing setting).

Uneven wear from side-to-side means something is worn/mis-adjusted in the steering--one tie rod is longer than the other. In general, rack and pinion is self-centering and wear will be even between the two tires if toe is bad--unless a tie-rod end is bad. I don't know much about steering box/drag link steering, but I suspect it could be out of adjustment.

Camber doesn't have much to do with tire wear on street-driven vehicles. Negative camber will wear the insides of tires, but you have to have a lot of it and you have to have a car that will go and stop better than the average car. My track car runs almost 2 degrees of negative camber in the front (3 in the back) and I got great tire wear. (2 degrees is rather noticeable by just looking at the vehicle)--Not until I added over 150 horsepower and 12 inch rotors, Wilwood calipers, then it would go fast enough and stop fast enough to wear the front tires under braking due to excess camber.

Unless your truck accelerates and stops like a Corvette, it isn't camber, it is toe-out and you have more on the driver's side. If the tie-rod is behind the hub, it is shorter on the driver's side than the passenger's side (for left-hand drive).

A reputable alignment shop should be able to align it or tell you what parts are too worn to do the alignment.

That's a wicked(good) explanation, and seems spot-on to me.

I want to thank you personally for the effort to provide clear, concise information. This is why so many of us rely on the info. on the 'Bolt.

You even had the forethought to include our right-hand drive brothers. Either you Rock or you Suck(KSHE95), and may I say:

YOU ROCK!

Checking/setting the toe-in on a straight axle is pretty easy to do yourself. Camber is permanent. If the kingpins are good & the axle is not bent it will be right.

Joe is absolutly correct with toe settings. AD trucks have no camber adjments..they are set at factory. Caster can be changed,but unless there has been an accident...no need to. Camber is same. Loose parts often the fault. Put jack under axle and shake top and bottom..hands on. Have someone look for wear. Good Luck..Sepp

I have to disagree about camber not causing tire wear on street driven vehicles. I'm an alignment mechanic by trade, and have seen the effects of incorrect camber. 2-3 degrees one way or the other, depending on vehicle specs, won't waer tires to much, but if there's an issue with the cross camber not being correct, or if it is beyond the 2-3 degrees, it can wear tires very rapidly.
One other thing, another reason that the toe is set in on rear drive vehicles is to counter the effects of the thrust caused when the vehicle is driven. The thrust forces tend to push against the joints, by setting the toe in, it allows for the slack in the joints to be taken up without loosing the toe setting.

Mine was doing the same (wearing inside of tires). I rebuilt the king pins and it disappeared.

If your axle is tweaked a little, I know there are places that can fix them. We have one in Oklahoma City that mainly does semi's. They'll do a small truck for about $100.00

The last time I checked those things was last summer. Also packed the wheel bearings. The king pins were marginal with a very slight movement, when I tried to move the spindle up and down. I am on the hunt for some replacements now, as well as tie rod ends. I have no idea if the axle has ever been in an accident, and even with the giant potholes we have, I don't think it is bent.


Thanks

A good example of a bad camber angle is a overloaded Ford with twin I beam front end. We have a bunch of these in our school bus fleet. They wear the inside of tires all the time.

Sounds like a good time to jack up the front and do some checking. King pins first, check for in and out movement at the top and bottom of the tire. Up and down won't affect much in the way of alignment, but will need fixed someday. Next grab the tire on the sides and twist it back and forth watching the tie rods and drag link. To really drive good, check the steering box adjustment. With the truck back on the ground, turn the steering wheel back and forth watching the left front tire, it should be moving as soon as the steering wheel moves. You should have as little as 1" or less of steering wheel movement before the tire moves.
Let us know what you find, Joe.

Finally got around to looking at my front end. Looks like the king pins are finished. So my next questiion is: Can the repair be done without using a press. I thought I read somewhere that on the larger trucks the axle had to be pulled to get get the pins out. It doesn't look any different than the half ton set up and I haven't seen anything in the manual that tells me so. Am I missing something?

Should be just the same set up only bigger. The only time you need a press is when the pins are stuck. Go ahead and try to remove them.

Sometimes you'll get by with no press. I wasn't so lucky as mine appeared to have been original. I pressed one out with a 10 ton press and had to take the other to a guy that used 15 tons. Both times it sounded like a gunshot when it turned loose.

Well worth the effort!

I'll get the parts on Wed. from the FLAPS. I've done this twice before on 1/2 tons but it was a long time ago. I am going to try and do it on the floor with out taking the axle down, but I have also lined up a place that will press them out if needed. I also want to make sure I don't have to go oversize with anything.

Thanks for all the comments, I have learned a lot about all this. Especially about alignment, caster camber and toe -in.