I put 275 70 R18 Goodyear Duratracs on my 12 JKU and was grinding at the air dam but only in reverse with steering wheel to full left going down a small divot in my driveway. 1.5 spacers and one inch coil spacers are also on the rig. I read a ton on this before I bought the tires and everyone said that there would be no rubbing issues with either wheel spacers or 1 inch coil spacers. I did both. Just a fyi. Now to shave the air dam down some.

 

That is true, you will have to trim the air dam. I installed 34's on wheels with 4.5" back spacing and had to trim mine also.

 

Why not just remove the air dam? Problem solved. I pulled mine of my 07 after upgrading tires and off my 2013 as soon as I got it home.

 

yea. just rip it off.

 

Rip it off, doesn't really do anything anyway

 

X4 on ripping it off!

Mine rubbed similar to yours with 2.5 BB with stock wheels and 1.5 spacers. For a while I sort of enjoyed backing out of parking spaces and freaking people out when they heard my Trail Grappler's dance with the airdam but the fun kind of wore off and I took it off when I stubbied my bumper.

 

Why size Trail Grapplers

 

Shaved off a few inches, no more rubbing.

 

1 trail and you won't have to rip it off. But please don't litter pick that useless thing up and throw it away.

I managed to sell mine to a junk yard for $20

 

Only thing it really does is help with hood flutter. I yanked mine the first day I had my JK.