Wheel Fitment Issue

troop12 · March 5, 2020

So I purchased a 2020 GMC Sierra Elevation about a month ago. I put a 2in Rough Country leveling kit on it a couple weeks ago. I bought a set of wheels and tires from Custom Offsets, 20x9 -12 offset with a 275 60 20 Nitto Ridge Grappler tire. They said those will fit this truck. I went to put them on today and they clear the caliper just fine but they rub like crazy. The back side of the tire makes contact with the inner fender where the mud flap would go if there were mud flaps on the truck. Mine does not have mud flaps just the cap that goes where the mud flap would be. Its not just a slight rub on the inner liner either its making pretty good contact. My question is what size wheel and tire can I fit without having any rubbing issues? I am not sure why its rubbing so much because this setup isn't that far off what the factory wheels and tires are. The only difference is the offset. If I run the same 20x9 with more offset will it clear? Add a spacer maybe? I wanted to get a little more info before looking at another set of wheels because I don't want to have this same issue again. Any information you can provide is greatly appreciated.

Thanks!

bullet3z · March 6, 2020

I have Fuel 20x9 with 0 offset wheels. I am running a 295x60x20 with no rub except for full lock right turn. I could probably do the mud flap mod and be fine. Just have not gotten around to it yet.

It sounds like your issue is in the -12 offset.

troop12 · March 6, 2020

Thanks for the response. Thats what I was thinking at first too. But I went to custom offsets website and they have a gallery of trucks with different wheel and tire set ups so people can look and see what fits and what not. There are people running bigger and wider wheels/tires on their 19-20 Sierras with a 2in level with no issue. Most are running a 20x10 -24 with a 33x12.5 and not having an issue or at most a slight rub at full turn. Thats what has me confused.

I called custom offsets to ask them about this. They said my set up should fit and not rub. They said to take my truck to a shop and have the sub frame moved forward. Has anyone ever heard of this? Can the sub frame even be adjusted?

lapoolboy · March 6, 2020

1 hour ago, troop12 said:

Thanks for the response. Thats what I was thinking at first too. But I went to custom offsets website and they have a gallery of trucks with different wheel and tire set ups so people can look and see what fits and what not. There are people running bigger and wider wheels/tires on their 19-20 Sierras with a 2in level with no issue. Most are running a 20x10 -24 with a 33x12.5 and not having an issue or at most a slight rub at full turn. Thats what has me confused.

I called custom offsets to ask them about this. They said my set up should fit and not rub. They said to take my truck to a shop and have the sub frame moved forward. Has anyone ever heard of this? Can the sub frame even be adjusted?

There is no sub-frame on your truck. They are apparently confused on what lift you have installed and are giving you wrong advice. If all you have is a 2" level kit, there is no sub-frame. Even if there were, there is no way to simply "move it forward" and to suggest it is ignorant. I used to respect Custom Wheel Offsets but what I just read calls that into question.

troop12 · March 6, 2020

That's what I thought. It sounded weird to me. All I have is a 2in rough country level. I made sure he knew that to. So if adjusting is not possible I'm still confused as to why my setup rubs but others running wider wheels with more offset and bigger tires do not. Is there anything else with the truck that could be wrong causing this?

pewterliftedz · March 6, 2020

The negative offset is what is killing you man, you can probably just pull the inner fender back with some zip ties to give you more room. Your options are move to wheels with a 0 offset, go to a shorter tire like 275/55, or just get used ot the rub.

Edited March 6, 2020 by pewterliftedz

troop12 · March 6, 2020

Ok so a 20x9 0 offset with my same 275 60 20 tires should clear better?

lapoolboy · March 6, 2020

26 minutes ago, troop12 said:

Ok so a 20x9 0 offset with my same 275 60 20 tires should clear better?

Absolutely. Stock wheels are somewhere around +18 offset for reference. Negative offsets are hard to make work without trimming stuff.

pewterliftedz · March 6, 2020

29 minutes ago, troop12 said:

Ok so a 20x9 0 offset with my same 275 60 20 tires should clear better?

Yes that will definitely help with the rub, maybe even completely eliminate it

troop12 · March 6, 2020

Ok, I will just get the same wheels with a 0 offset and same size tire. Thanks for the help.

Kintnerboyredoubt · March 9, 2020

I have a similar setup to you, 20x9 -12 with 295/55/20. I had done the mudflap

mod originally which got rid of a great deal of rub. My setup was a Sierra Sle with factory 2” lift. It rubbed badly before the mud flap mod after that it rubbed mostly in reverse and on the front lower bumper valance.

Recently I installed a 2” rough country leveling kit (basically the same setup @lapoolboy is running) it doesn’t rub at all now. Our sierras have smaller wheel wells than silverados so fitment issues are common and frustrating. Your tire is a bit taller than mine (60 vs 55 but with the width difference it should be negligible) fwiw I’m running bfg k02 which are known to run small.

Try the mudflap mod first ( I know you said your truck doesn’t have mud flaps but likely it still has the bracket for them behind the wheel liner) after that a small trim on the lower valance should alleviate your issue. If you don’t want to trim you’re going to have to add moar lift. Good luck.

Edited March 9, 2020 by Kintnerboyredoubt

Kintnerboyredoubt · March 9, 2020

On 3/6/2020 at 5:30 AM, troop12 said:

Thanks for the response. Thats what I was thinking at first too. But I went to custom offsets website and they have a gallery of trucks with different wheel and tire set ups so people can look and see what fits and what not. There are people running bigger and wider wheels/tires on their 19-20 Sierras with a 2in level with no issue. Most are running a 20x10 -24 with a 33x12.5 and not having an issue or at most a slight rub at full turn. Thats what has me confused.

I called custom offsets to ask them about this. They said my set up should fit and not rub. They said to take my truck to a shop and have the sub frame moved forward. Has anyone ever heard of this? Can the sub frame even be adjusted?

I saw a bunch of people claiming they weren’t rubbing running some big offsets on just a level on there as well. After seeing first hand on my own truck there is absolutely no way they didn’t trim or do anything to get those to fit unless they somehow drive without ever making a turn...

Flatblack83 · March 9, 2020

On 3/6/2020 at 11:37 AM, lapoolboy said:

Absolutely. Stock wheels are somewhere around +18 offset for reference. Negative offsets are hard to make work without trimming stuff.

Stock wheels are 27-28 mm if u look up the specs.. ...My opinion.... If u take a look quite a few have 15-20mm wheels with no rub. Plus I see up to o offset with minimal cutting. The negative #'s u see all trim,rub,cut, etc...unless your running a 6 inch.

A 275 60 20 is what the custom silverado comes with on stock wheels. 295 60 20 still fits on stock wheels with no rub. So with yours being a GMC I can see no problem fitting the 275s.

Edited March 9, 2020 by Flatblack83

troop12 · March 9, 2020

10 hours ago, Kintnerboyredoubt said:

I have a similar setup to you, 20x9 -12 with 295/55/20. I had done the mudflap

mod originally which got rid of a great deal of rub. My setup was a Sierra Sle with factory 2” lift. It rubbed badly before the mud flap mod after that it rubbed mostly in reverse and on the front lower bumper valance.

Recently I installed a 2” rough country leveling kit (basically the same setup @lapoolboy is running) it doesn’t rub at all now. Our sierras have smaller wheel wells than silverados so fitment issues are common and frustrating. Your tire is a bit taller than mine (60 vs 55 but with the width difference it should be negligible) fwiw I’m running bfg k02 which are known to run small.

Try the mudflap mod first ( I know you said your truck doesn’t have mud flaps but likely it still has the bracket for them behind the wheel liner) after that a small trim on the lower valance should alleviate your issue. If you don’t want to trim you’re going to have to add moar lift. Good luck.

Thanks for the info. What exactly is the mud flap mod? My truck had big mud flaps on it when I got it but I took them off and put a factory cap on there so it sits flush with the rocker. Nothing hangs down beyond the rocker. But I did notice behind the inner fender liner a black bracket. What is the mod that has to be done?

Again thanks for all the info!

troop12 · March 9, 2020

14 hours ago, Kintnerboyredoubt said:

I saw a bunch of people claiming they weren’t rubbing running some big offsets on just a level on there as well. After seeing first hand on my own truck there is absolutely no way they didn’t trim or do anything to get those to fit unless they somehow drive without ever making a turn...

Yes, I saw this too which is why I was confused. A few people in the custom offsets gallery claim they're running 20x10 -24 with a 33x12.5 on a level with no rub, no trimming on new body Sierra (not AT4). I tried 2in spacers with my 20x9 -12, 275/60/20 just to see how bad it would be and you get maybe one full turn before the back side of the tire burys into the inner fender.