37” tires what backspacing you using

[Hockeydad55]

Hey guys I'm looking looking to put 37” tires on my truck and lift. For anyone out there that has put 37” tires on there 2500/3500 could you tell me what backspacing you used on the wheels and if you have any rubbing with them. Pics would be nice too. I know it should be around +18 but i want to put Toyo 37x13.50 which are 14.5 wide really and i don't think +18 will work.
thanks for the help

 

[LateToTheParty]

Since you mention 14.5 width for the 37x13.5, I assume you're going with the 17" Open Country MT and will be mounting them on the same 11" wide wheel that Toyo used when collecting their width measurement.

So for that wide of a wheel, you're absolutely correct, +18 is going to rub like crazy.

That said. If you were thinking of going with a narrower wheel, more like 9" wide, then the actual mounted width will be narrower than that which Toyo provides in their specifications. I still think +18 would rub, but you may be able to get away with +25 (though I'd still plan on trimming).

 

[Hockeydad55]

Since you mention 14.5 width for the 37x13.5, I assume you're going with the 17" Open Country MT and will be mounting them on the same 11" wide wheel that Toyo used when collecting their width measurement.

So for that wide of a wheel, you're absolutely correct, +18 is going to rub like crazy.

That said. If you were thinking of going with a narrower wheel, more like 9" wide, then the actual mounted width will be narrower than that which Toyo provides in their specifications. I still think +18 would rub, but you may be able to get away with +25 (though I'd still plan on trimming).

Thanks for the info and yes i would be using a 9” wide wheel but wouldnt the wheel be even closer to radius arms and sway bar with a +25 leading to rubbing them or is that not the problem its hitting wheel well thats the problem with a +18 and that wide of a tire
Thanks again

 

[Hockeydad55]

Oh and yes it would be open country m/t 17”

 

[LateToTheParty]

Thanks for the info and yes i would be using a 9” wide wheel but wouldnt the wheel be even closer to radius arms and sway bar with a +25 leading to rubbing them or is that not the problem its hitting wheel well thats the problem with a +18 and that wide of a tire
Thanks again

First point of contact is going to be the pinch weld in the back of the wheel well, which the +25ish offset helps to avoid, but then yes, you do run the risk of rubbing sway bar and/or radius arms.

If you don't mind the trimming of the pinch weld, then +18 or even +12 will keep you out of the stock sway bar and the radius arms, but further enforces the need to trim.

 

[Hockeydad55]

First point of contact is going to be the pinch weld in the back of the wheel well, which the +25ish offset helps to avoid, but then yes, you do run the risk of rubbing sway bar and/or radius arms.

If you don't mind the trimming of the pinch weld, then +18 or even +12 will keep you out of the stock sway bar and the radius arms, but further enforces the need to trim.

Yes i don't mind trimming wheel well but don't want to grind pinch weld so i guess i will go with there 12.5. So with there 12.5 tire what do you suggest ideal backspace would be and again thanks for all your help.

 

[Hockeydad55]

Oh and probably doing carli 2.5-3.25

 

[LateToTheParty]

With that, my suggestion would be +18.

There are quite a few threads in the Wheel/Tire sub-forum though that you may want to read through. Everyone seems to have slightly different thoughts/opinions and some real-world examples as well.

Definitely some good reading.

 

[Brewbud]

I went with +20mm on a 9" wheel. This is close to a 5 3/4" backspacing. I have a 3.25 Carli Dominator with Yoko 37" X-ATs. I still had to trim the liner and pinch welds. Trimming the pinch welds and the liner is easy.

 

[Hockeydad55]

AEV has a 17x8.5 with a +27 backspace and are suppose to be just for the ram i wonder if that would be even better

 

[Brewbud]

I get confused with offset. It is easier to use backspace numbers when comparing different wheel widths. 8.5" with 27mm offset is a backspace of 5.81". 9" +20 is 5.79" backspace so almost the same. I went with 9" +20mm because CJC suggested it and they upgrade so many Rams with Carli/Thuren.

 

[Rockcrawlindude]

just look at the dozens of people on this website who run 37s. There are entire threads dedicated to this. @LateToTheParty is spot on with what he said above.

I’ve seen people with +12 up to +27 running 37s no problem on here. There isn’t much difference between the two (~1/2 of backspacing) +18 is a sweet spot in the middle. These are all 9” wide wheels so it’s apples to apples.

personally, If i was going to a 37, i would run a 37x11.50 or a 37x12.50 instead of a 13.50. Because I like the look better, less tire meat poking out and less likelihood of rubbing.