larry0071

37x13.50-18 on 18x9 5x5 and 5" backspace?

I am looking at tire options, 37x13.5 and 37x12.5 and want to know if either would work or is the 13.5" flat out no good with this wheel. Maybe 37" is out with a 5" backspace? What about a 35"x12.5" tire on that same wheel.

The wheel is a LRG model 106, part # 10689073700 going on a 2014 Willys with 2" suspension lift and 1.25" body lift. I don't think it matters, but a ProRock 44 Unlimited is being installed in a couple weeks. Lower control arms are Rock Krawler, Ruff Stuff DOM 1 ton offset tie rod and the rest is all Synergy (track bar and drag link).

I really had plans on the STT-Pro in 37x13.50, but after owning the wheels and storing them for almost 2 years, I realize that they are less than optimal for going to large tires based on the recommendations I see to get at least 4.5" backspace, if not go to 4" or even 3.75".

So how screwed am I? What would work, what would not?

I did toss the tires onto craigslist to see if anyone wants to buy them while they are all 5 still new in the box.

PsychoCupcake

I wouldn't say you are screwed per se but you are going to run your and other things when you turn. Not only is it a wide tire but then you add the less than optimal backspacing on top of that and it's Rub City. For reference, I'm at 4" of backspacing and 37x12.5 tires and I rub. Had to adjust my steering stops to fix some of it. For me, it's minor enough at this point that it's livable but I'm guessing yours will be worse. You'd be much better off with less backspacing, as you mentioned.

PsychoCupcake

I don't know much about prorocks, but is the 44 unlimited any wider than stock axles?

larry0071

I am under the impression that it is an exact match to factory width. My axle just got built yesterday and should be on a truck heading at me this week. So I would say that for the moment, I also don't know much about a ProRock!

sa29560

You need 3" bs or less. With 5" bs and 1.5" spacers you might get lucky.

twinz33

Spacers are a must with those wheels.... 1.5in spacers will most likely not be enough.. I ran 37x13.50 toyos on a 9in wide wheel with 3.5in backspace and 3in of lift. At full turn I rubbed the frame and factory control arms

larry0071

I don't like you guys

Your telling me what I feared the most. I have spacers on the stock wheels/tires now, but was not really wanting to have spacers after installing the ProRock and moving up to the new wheels and large tires. So I have the option of keeping my spacers and moving them to the ProRock 44, or dumping the wheels and moving to a new wheel.

What if I said "screw it" and I dropped to a 35"x12.50 STT Pro? Would the same 5" backspace be a problem.

PsychoCupcake

I had 35s with 4.75" of backspacing and all was good with that in terms of rubbing. So likely that extra 0.25" won't cause too much of an issue.

I think you have a few options here. Consider new wheels with much less backspacing. Also a 37x12.5 instead of 37x13.5 will help as well. But right now you have several things working against you. Will likely take a combo of changes.

Sorry to be the bearer of bad news. They other option is you crank your steering stops as far out as they'll go and reduce your steering angle so you don't rub. Not the optimal choice but it's an option...

larry0071

I wish I could get the STT Pro or the Nitto Mud Grappler in a 37-12.5-18. I would rather have the 12.5, I never wanted the 13.50... it just was what they make.

I am so freaking broke and out of money. I can no longer afford to eat after I gave all of the money in my world to Eric at Northridge!

I doubt I will be able to sell the wheels for anything near what I paid, I put them out at $175 each for all 5 on CL versus the $230 each I paid.

nthinuf

Check the specs on the STT Pro. There is only a .3" difference in section width (overall width) between the 12.50 and 13.50, 13.0" vs 13.3". If you want the 13.50's, get them, I don't think that 'point three' of an inch is enough extra width to stop you buying one vs the other. (just looked at the 13.50x18 mud grappler, it shows a section width of 14.17".)

If you do talk your self into 17" rims, also note that the 13.50x17 STT is an E load tire, if that matter to you. The 12.50x17 is D load.

(My local discount tire had a set of 37x13.50x18' stt's sitting there from a cancelled order that were offering a decent discount on. I would have walked out with them, but didn't find any 18" rims I liked enough. Ended up ordering 12.50x17's and MB11's.)