Front End Problem on Chevy Van.

[George7941]

Vehicle referred to is a 1997 G3500 diesel van. The front tires are wearing out quite severely on the outside part of the tread. A mechanic friend of mine suggested that it was probably due to worn lower ball joints. I checked them and there is no slop at the ball joints. I checked them by supporting the front of the truck on jackstands and then jacking up the lower control arm with a floor jack to remove the spring load from the lower ball joints.

I checked toe-in and there is excessive toe-in, the fronts of the tires are closer together by 7/8ths of an inch than the rears. GM specifies 0.24 degrees toe-in. I will set the toe-in to factory specs.

My question is, would this excessive toe-in have caused the outer edge wear on the front tires? One book that I consulted stated that outer edge wear is a sympton of excessive toe-out, not toe-in.

 

[onion]

Yes, excessive toe-in can cause the outside edges of the tires to wear. More specifically, it usually causes a wierd looking wear pattern on the tread, where each lug will be worn more on one side than the other as the tires scrub along.

I'd be curious as to how the toe-in became that excessive. As steering linkage and suspension wears, toe generally goes "out". I'd wonder if some monkey has been wrenching around on it.

I've also seen steering linkage bent when some rocket scientist pulled a truck out by attaching the chain to a tie rod. I'd check things real close, because 7/8" is a LOT of toe... I suspect that somebody, somewhere, has done something stupid.

 

[onion]

On further reflection, I'm gonna take part of that post back. It depends on the design of the suspension and exactly what had worn... but toe can go 'in' as suspension wears. Lower ball joints would be just one possibility- I'd also look at control arm bushings and upper ball-joints... along with loose bolts and/or signs of stupidity.

In addition to toe, you'll also want to look at caster & camber. Positive camber can wear the outside of the tires.

 

[mechtech2]

That is massive toe in.
It will cause the wear symptoms that you saw.
But don't forget to check the upper ball joints, and wheel bearings.

 

[George7941]

If any monkey has done something stupid on the truck, that monkey would be me since I am the only one who works on the truck. Van is a company van.

A couple of years ago I replaced the idler arm, the pitman arm and the drag link and did not get an alignment done since none of those components affect the alignment much. It is not like you are replacing a tie-rod end. BTW the van has 280K mi and the work mentioned above has been the only work ever done on the front end.

 

[punisher]

Usually when you have a toe concern the tread will "feather" at each groove. Wear on a particular section of tread, the outboard portion for instance, is many times caused by a camber concern, aggravated by low inflation pressures.

280K miles is impressive to have gotten away with that little front end work. I worked on a fleet of Dodge vans for a few months and it was front end nightmares once they hit 100K miles.

 

[alreadygone]

Quote:

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My question is, would this excessive toe-in have caused the outer edge wear on the front tires? One book that I consulted stated that outer edge wear is a sympton of excessive toe-out, not toe-in.

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Throw that book AWAY!!!!

7/8" is a lot of toe. I'd almost bet something is bent.

Bob

 

[George7941]

"280K miles is impressive to have gotten away with that little front end work."

I forgot to mention that I did replace the idler arms once before at around 100k mi. The van has never had an alignment. Being a diesel there is a fair bit of weight on the front end and, being a moving company van, the van does see some hard use. The performance of the front end has been very good and I would like to think that my meticulous greasing of the front end at every oil change(5000mi) contributed to the good performance.

I don't think inflation pressure is a cause here since I have always run the tires (LT245/75/16 Michelin M&S) at 65psi and never had uneven wear before.

 

[onion]

"Feathering"... that's the word I was looking for. Thanks, Punisher.

Wheel bearings... another good suggestion.

I've seen some strange things now and then with replacement parts- especially from discount parts stores... it wouldn't surprise me a bit to run across a drag link that was 1/4" shorter than the original.

At this point, regardless of WHY the toe is so far out... the only thing to do is look everything over thoroghly and align the font end. If you're measuring toe with a tape measure, make sure you measure the front and rear of the tires at the same height... otherwise camber can throw off you measurement.

 

[cousincletus]

FWIW I replaced an idler arm on an S-10 and it put the front end out of alignment. The Moog replacement idler arm was a little different. The guy at the Chevy dealer who did the alignment told me to always do an alignment after you replace any front end component.