Steering wheels uneven tire wear - toe-in issue?

[therooster2001]

Ok, best searchable subject I could think of.

I have some funny wear on my front tires. It seems to be both of them. It only appears to happen to the outer most tread on my Goodyears. Here's a good pict of the issue.


A fellow SS turned me onto this in the TM's. Work package 493, in the third volume of Field Maintenace.



Anyone have experience in this? Where would I find that guage?

 

[therooster2001]

I've checked the usual spots for the gauge by NSN and part number (referenced in the 5th TM for the 826 equipment package), and no joy.

I could also be barking up the wrong tree on this, but it seems like the cause.

 

[VPed]

I put a staple in each tire on the tread, towards the rear of the truck. Then measure the distance between the two with a tape measure. Roll the truck forward until the staples are both on the front of the tires and repeat the measurement. The difference is your toe in/out. Best results are on level ground, with the tires exactly straight ahead.

Could use thumb tacks or roofing screws just as effectively.

 

[acme66]

Are you sure it isn't stuck in 6 wheel drive? Otherwise I have fought tire wear on my trucks with some success. I strapped timbers to the tries so that they stuck out on each side and were level with each other then measured between them. I found you could adjust toe in much closer. One one truck (with Goodyears) it cured the issue, on one running Michelin XL's it had no effect what so ever. I use mine as tour trucks and put very high miles on them, 150-200 miles a day in the summer on gravel roads mostly.

Ken

 

[therooster2001]

Are you sure it isn't stuck in 6 wheel drive?

I sure hope not, I was going 68 MPH with it last week. We changed the tire thinking that it was a cupping issue (it was also bouncing too, which I think was fixed by the dogbone), and it did the spare the same, in no time. We also thought it was a turning thing (the inside turning wheel gets more wear on pavement), but it's pretty excessive, so I think it's the toe-in..

I strapped timbers to the tires so that they stuck out on each side and were level with each other then measured between them. I found you could adjust toe in much closer.

I put a staple in each tire on the tread, towards the rear of the truck. Then measure the distance between the two with a tape measure. Roll the truck forward until the staples are both on the front of the tires and repeat the measurement. The difference is your toe in/out. Best results are on level ground, with the tires exactly straight ahead. Could use thumb tacks or roofing screws just as effectively.

GREAT ideas on how to get this done without the mysterious gauge. You guys are wicked smaht... I'll try it out and post results.

 

[therooster2001]

I checked to be sure it wasn't in 6wd by jacking up the front, and spinning a tire a couple of weeks ago. The front driveshaft continued to move, then flipped the front switch, and it won't. I did a quick and dirty measure and it didn't seem that off, but to do so I wanted Soldier B and actually move the truck or do the timber trick, so this isn't confirmed yet. More to come, hopefully In a more timely manner. I was more concerned over the flat tire in the back (a cold CTIS valve).

 

[Gralmk]

Were they like that when you got the truck? If so, mostly cause by - drivers running with front wheel locked on dry pavement! If it happened after you had the truck, I'm sure you didn't do that, so it would most likely be the alignment.

 

[juanprado]

I had the same issue and believe it is worn OE hydraulic shocks. Shocks causing cupping and the bounce, incorrect toe feathers the tire.
I upgraded to Gas Monroe Truck magnums. Rides heck of a lot better. OE hydraulic shocks are literally dinosaurs....

 

[Scrounger]

The picture of the tire you show is classic tow in problem. Specifically toed in too much. What you have is the front tires are pointing in instead of pointing forward. The result is the outer edges of the tires are essentially being pushed forward. There are several ways to fix it. It is best to have soldier B to help with measurements. I like to lift the front axle and paint a nice white strip all the way around the tires in the middle of the tread. Then follow it up with a nice scribed thin pencil line. Then place the tires back on the ground. It is important to have weight on the axles for measuring. Take a tape measure and measure the distances between the pencil lines at 9 and 3 o’clock. You want to see around 1/16” less in the front. If it is more than that adjust the toe-in till it is 1/16”. Since you probably don’t have turntables for the front wheels several sheets of Tyvek house wrap and a piece of steel under the front wheels will do. It will make it easier for the wheels to turn when you are making the adjustments.

 

[73m819]

I had the same issue and believe it is worn OE hydraulic shocks. Shocks causing cupping and the bounce, incorrect toe feathers the tire.
I upgraded to Gas Monroe Truck magnums. Rides heck of a lot better. OE hydraulic shocks are literally dinosaurs....

How about giving a part number for those shocks, thanks

 

[JohnnyBM931A2]

How about giving a part number for those shocks, thanks

Agreed

 

[Ford Mechanic]

If it's a toe issue it should be the same wear on both sides. Toe will always be equal on both sides when driving down the road. It may only be off on 1 side (moot point with the steering design on these trucks) but it will equalize resulting in issues with steering wheel center and of course tire wear.

Cover all your bases, do a quick check of all your steering system for loose parts. Jack up the front wheels and push in at the top, or pry up under the outer edge of the tire. This is checking your king pins. Loose play here will wear just the affected tire.

Shake the tire side to side to check tie rod end play.

The mistake alot of people make checking a front end is putting out too much when checking for play. You just want to shake the tires enough to get the play, not enough to actually turn the wheels back and forth.

I can't say I've ever ran across a solid axle with a tire wear issue caused by shocks though. Twin I-beam axles, sure seen several of them. Just my experience.

 

[juanprado]

How about giving a part number for those shocks, thanks

Many thanks to wheel spinner who did the original research for the front of a m939 Monroe Truck Gas Magnum Series 65 part number 65116. I bought them from O'reilly's where my son works. One day special order.

http://www.steelsoldiers.com/showthread.php?107144-5-ton-shock-absorbers&highlight=shocks

http://www.oreillyauto.com/site/c/detail/MONF/65116.oap?ck=Search_65116_-1_1382&keyword=65116

 

[therooster2001]

Definitely think with proper measurements and procedure I'll get the toe in issue identified and solved. Thanks all for the validation. Again, I'll post some picts and my experience here.

What's a good way to gauge the shocks? Or do the old ones just suck so much that its worth it to replace anyway?

 

[adamsoffroadperformance]

The front axles in the 5ton trucks also are setup with a slight positive camber which will also cause the tires to wear like that. Kneel down look at the truck from the front you can see the tops of the tires lean outward.

 

[Ford Mechanic]

Hard to guage old shocks on these big heavy trucks other than pull them and check by hand. Or if you see evidence of leaking

 

[Swamp Donkey]

Many thanks to wheel spinner who did the original research for the front of a m939 Monroe Truck Gas Magnum Series 65 part number 65116. I bought them from O'reilly's where my son works. One day special order.

http://www.steelsoldiers.com/showthread.php?107144-5-ton-shock-absorbers&highlight=shocks

http://www.oreillyauto.com/site/c/detail/MONF/65116.oap?ck=Search_65116_-1_1382&keyword=65116

Between your post and one in the linked thread there are 3 part numbers listed. So which ones are we using? The 65116 I hope, because I got a line on some for cheap.

Do these have the same amount of travel as the originals?

 

[therooster2001]

The 65116 is what I used. It was a piece of cake, literally 6 min a side. I didn't notice much of a difference in the on-road bounciness, I still think it's no weight in the bed. BUT, the old shocks were absolutely toast. They were so old, the telltale oil leak was gone too, so couldn't have known without removal. There is no weight on them, so just two nuts and they are on / off. I scored them for $40 a piece, plus shipping, but had a 10% off, so $80.29 for two shipped. Finditparts.

EDIT: Looks like they are up to $54.

 

[therooster2001]

Ok, time to put this thread to bed. Did the toe-in adjustment, 1/2 inch off. It made a big difference in handling, and I'm sure my tires will thank me. It's really easy, and a ton easier with solider B. Everyone should check theirs. BTW, on my Goodyears, there is a center mark every other tread. Very helpful in getting center of the tire.