Tires: tires, dodge ram quad cab, ram quad cab

Question
QUESTION: I have an 06 dodge ram quad cab 4x4 short bed with less than 34000 miles on it. I was having a vibration in the front end and took it into the dealer. They said my tires are cupped and need replaced. They rotated the tires for me and when I drove the truck again the whole front end shook like crazy. I took it back and they said the same thing, need new tires. Is this normal for tires to only last 34000 miles? I looked at the tires and they look fine, have plenty of tread and do not look worn that bad to me, but i am no expert.

ANSWER: Joe,

Normally, when tires are the source of a vibration, rotating the tires results in the vibration going away.  Since it didn't, it leads me to believe the source of the vibration is NOT the tires.  (I'm assuming the vibration showed up again shortly after the tires were rotated, not weeks or months later.)

The second part of this is about what causes a tire to "cup" - and that's alignment, typically toe in.  So, of course, the worse the alignment, the sooner it shows up.  Since vehicles need toe in to be stable (toe out is unstable), in some respects, regular rotation is required to prevent this natural wear pattern from getting so bad it causes a vibration - the other positions wear a different pattern into the tire.

So my guess is that the problem is not the tires, but it is understandable that tires might cause a vibration if they were not rotated regularly and the alignment is off.

---------- FOLLOW-UP ----------

QUESTION: I have rotated the tires on a regular basis,the steering does not pull one way or the other and the wheel is straight when going straight. When i took the truck back to the dealer a 2nd time they put the tires back to where they were bofore rotation, the shaking is gone, but the vibration is still there. Could one of the tires/rims be out of balance and cause this type of prolem?

Answer
That's for the additional information and the clarification.

I suspect there are 2 issues:

1)  The alignment is bad and that is causing irregular wear in the tires.  That's why it is vibrating - and of the 2 pairs of tires, one is much worse than the other.

2)  There is something loose / worn in the front end that when the more severely worn tires get there it causes a much more severe vibration.

Balance could also be a cause, but that seems so obvious.  Plus, I suspect the dealer already balanced the tires when he rotated them.

So I would recommend you go somewhere other than the dealer, have them do an alignment, and while they are under there, look for something worn out.  Plus get new tires.