So I just upgraded my 98 RAM 2500 from a 285/75/r16 tier and wheels to a 275/70 18 inch wheel. I seem to be having issues with a right side tier rub on the control arm but nothing on the left side. The truck has a 2" lift on it and plenty of clearance from the tubs, bumpers and everything else. The only rub I can see of is off of the back side of the tier on the control arm. Does that mean the the 18s are going to be to big and I need to stick with 16s or 17s?

 

Probably means that your wheel offset is a little too much positive.

https://www.wheelpros.com/page/offset-explained/9

 

If you didn't install an adjustable track bar to re-center the axle for the lift, that's your problem. The axle has shifted to the driver side limiting the distance to the suspension. 2500s already have that problem over 1500s because they sit higher while using the same track bar. You lifting it more without taking into consideration all that changes in the suspension geometrically is your downfall.

 

Yeah, but the tires are only .4 inches different in diameter. Measure the distance between the rim where it contacts the hub, and the rear of the rim. For both the 16s that didn't rub, and the new 18s. I think you will find the 18s are positioning the tire deeper into the truck.

 

can I correct the rub with a spacer on the right side, or am I going to have to drop back down to the 16s?

 

Measure that backspace yet? I wouldn't put one spacer on - you'd want a set of 4. I'm not a fan of spacers, but people do use them. I'd just find appropriate offset rims, or live with it - it can be driven without lock to lock turning.

 

Plans are on a different wheel when money is available, but wheels and rubber is going to run me 2k, so one step at a time. Thanks for the input. Also I have not measured as yet, but will do.

 

Could get an adjustable trackbar, and center the axle better. Would be cheaper than tires/wheels..... but, still, a couple hundred bucks. (but, it IS something that should be done anyway.)