Bought a 2009 GMC 2500HD Z71 a few months ago. The tires are larger than stock, BFG AT KO 285/70/17s, so I wasn't surprised when they rubbed. Until I saw that it wasn't both tires, and it wasn't on the bumper plastic like I've come to expect with lifted trucks/bigger tires in the past.

The driver's side rubs at full lock, both directions. Passenger tire never touches. You can see the clean area below where it's hitting.

Turning Right:

Turning Left:

Any ideas what would cause only one side to rub like that?

Alignment.

^^^

Yep!

Have you checked your suspension/joints up front?

No, I haven't. I just bought the truck, time to do some digging.

The parking brake cable pushed against the back of the fender liner where it is rubbing. Drilll a couple of small holes in the fender liner so you can get a ziptie through it. There should be a body mount that you can run the ziptie through on the backside to keep a little pressure pulling the fender liner back.

Norcal fender mod. Do it. Then put even bigger tires on it. You'll rub off what you don't need.

^ That's for your turning left problem. You may be able to fix the fender liner rub turning right the same way. Is it rubbing the trac bar turning right as well?

Looks like his track bar is rubbing at full lock as well. Barring you having a different size tire or different rim backspacing on the driver's side, it's likely an alignment thing.

I keep thinking of other possible remedies but I don't know how to edit on a phone.

If there's nothing pushing on the front of the fender liner, you can reshape it a little with a heat gun. Just don't melt it!

And like everyone else said, get an alignment. Way cheaper than ruining tires or suspension bushings.

Shift the front clip.

thanks guys - I'll go the alignment route first.

Then may have to look into this NorCal fender mod when it's time for tires (coming up soon.)

Well, alignment didn't solve it. Looks like it's time to get out the recip saw and go NorCal on these fenders.

I only rub when turning sharp right, my alignment is good also.

I'd need to raise the front end a hair or wheel wheels with a lower offset to get the tire away from the frame

You can also raise the front end slightly by cranking your torsion keys. You'll want an alignment after this is done as well. You also don't want to raise too much as it can put some front end parts in a bind.