I have a 2004GMC 3/4 ton Sierrra 4 wheel drive.

The rear are not adjustable on your truck. However, some shops, based on equipment, use the rear wheels as a locater point.

There is rear alignment adjustment on this model, this should be checked with the new tyres.

I stand corrected. I didn't think they had it on this year.

I now stand corrected, was looking at the rear wheel steer version, looks like there is no adjustment, well worth re checking, just to save face.... ensure all rear suspension components are serviceable as this can affect rear tyre wear rates and get them rotated as required as well.

You know, they change things so often, it is hard to keep up. I thought it was a straight axle (rear) and no adjustment. Hay, that's what makes our job interesting. So, do you agree, mhpautos, that this vehicke can only have the front aligned? That is what I believe. Need your conformation to assure lotto38 so he/she knows what to do.