Front tires

Maintenance/Repairs
1

Ok, I have a 2003 Silverado. The tires on the front inside keep wearing out, just the inside, it has been in the shop twice they can’t seem to figure out whats causing it, it has been aligned, my question is could a grill gaurd cause the “shimy” I sometimes feel? This is my fourth set of front tires in three years.

2

You need a new shop. Bad struts or any of many suspension parts could be at fault. They are missing something.

3

2 thoughts:

  1. Most vehicle manufacturer’s alignment tolerances are too wide. Alignment values need to be in the inner half of the tolerance. Your shop should have figured this out by now, and if they didn’t, you need to find an another one.

  2. I’ll go out on a limb and predict this is a long wheelbase truck - crew cab, extended cab, something like that. And I’ll bet you do a bit of “city” driving - meaning lots of turns compared to straightline driving. If true, then the “ackerman” may be the problem. This is something that gets measured during an alignment (It’s the change in toe when the steering wheel is turned and it’s called “toe out on turns” or something like that) but it’s only a check - you can’t “adjust” it. Changing it involves shims in unusual places, or bending steering components - not something recommended for the amateur (and some pros as well!). For practical purposes it requires someone to “guess” what it should be.

See if your shop understands akerman and if they do, that would be a good sign.

4

You did not mention whether the tire pressure is as listed on the driver’s door tag. I imagine it is, but I I suggest you check it.

5

I agree with the others, it’s likely to be an alignment issue. Find a real alignment shop (not a tire place) and have a good alignment performed.

6

Look in the Yellow Pages under “Wheel, Frame & Axle” to find a REAL alignment shop…

7

inner tie rods would be my guess been there done that. the inside of the tires wearing out means it is toed out too much or severe negative camber more likely toed out. but if you have been to the same shop twice and they cant find the problem i agree with the others find another shop.

8

Thanks all I appreciate the help. Think I will take it to a different shop. Thanks again.

9

The short answer is alignment, but there may be more to it than that. Two things in the alignment can be at fault, either the camber or the toe-in. You can look at the tires and get a pretty good idea about the camber, are the tires pointed in at the top? If you can visually see that the are, then that is the problem. If you have to use a level, then it could be, but not as likely. If you use a level, held vertically against the side of the tire, and it shows the tire is in at the top, then pull the top of the level away from the tire. If it takes less that 1/4" to be plumb, I’d say it is probably in spec, I don’t happen to know the spec for this vehicle, but this is just a rough check anyway.

You can do a rough check of toe in in the driveway too by using a length of 2x6 and a straight edge. Slid the 2x6 behind the tires, 6" dimension vertical. the top of the 2x6 should be touching both tires. Now place a straight edge along the face of the tire on one side, the straight edge parallel with the ground and resting on the 2x6 top edge. Mark a line on the 2x where the straight edge crosses it, repeat on the other side. Now move the 2x to the front of the tires, place the straight edge along one tire and adjust the 2x until the line drawn on it is aligned with the edge of the straight edge. Now go to the other side and put the straight edge against that tire, The straight edge should be inside the drawn line by somewhere between 1/8" and a 1/4". If its not, then you need an alignment. If it is ok, then you need to look for a worn component.

The next thing to do would be to have someone start the engine. Have them turn the wheel quickly left and right while you observe the tie rod ends, idler arm, pitman arm and ball joints. If any of them are worn, you will see them moving around in their sockets. The next thing to check, and I don’t have a simple way of checking them would be the trailing arm (aka strut rod) bushings. They could allow excessive toe out at speed but everything would check good on an alignment rack. If your vehicle has an A-arm for the lower control arm, then it may not use a trailing arm, but the A-arm bushings could be worn out.