Trimming needed for… same size tire as stock??

Hey all!

maybe this is a dumb question but, I just had some new Falken AT4ws fitted. Same size as stock, 31x10.50R15. I’ve noticed while turning over bumps, the tires are rubbing the plastic fender well *behind* the tire on both sides.
I found this surprising considering A) I do have a mild 2” lift up front and B) as far as I’m aware these are the stock size.

Has anyone else had to trim fender liners/pinch welds without having even sized up the tires? It’s not a problem, I’m gonna do the pinch weld mod anyway to be safe… I just thought it’s kind of weird

 

Are the wheels the new tires are mounted on the same as before? Or are you running different ones?

 

Same wheels! They’re just the stock 15s. Same everything aside from the tire brand. The previous owner had a set of (new) corsa all-terrains put on just before I bought the truck last year. They sucked big time and had zero wet traction, so yesterday I replaced them with the AT4Ws.

Edit: the only thing I can think of is that the tread on these makes them slightly larger than 31s. The tread on these tires is DEEP, and I actually noticed my CB antenna now scrapes the garage, where it didn’t before. The Falkens are definitely 31s but I think they have to be at least a half inch taller than the Corsas were.

 

I know some brands and models can be a wee bit different in size. For example I have both BG KO2 and Rugged Ridge same size but the KO2 is ever so slightly bigger.

 

Yeah that’s what I’m thinking. If you check the edit on my previous post that kinda matches my theory

 

The same size tire in an aggressive mud tire or an E rated tire is slightly larger in diameter than a typical P rated tire.

Your tires are (ABOUT) 31" tall, 10,5" wide (AT THE SIDEWALL) and fit a 15" rim. But there is no standard for the width of the tread that contacts the ground. You just have to check manufacturers specs. The tread width can be 1" or more wider on some tires even in the same size.

 

There are subtle differences in different manufacturers sizes. They're small differences.

But 31s, I don't believe, are "stock" on 15" rims. See image.

265-75-15 which is another standard size for 15s is 30.5 inch.

 

Interesting. I think both the Corsas and the AT4Ws are C rated, if that makes any difference. But yeah that makes sense, thanks for clarifying that.

The sticker on my door sill is a little different than yours. I don’t have a picture on hand but mine reads 10.5R15 rather than P225/75R15. Although it doesn’t actually specify “31x10.5R15” but I inferred the 31 based on the research I’ve done (as well as the last set of tires that the PO had been running).

 

I’m pretty sure mine specifies 31x10.5/15 on the door sticker. I can look at it tomorrow to be sure, but right now my truck is 200 miles away. I never had any rubbing running 31x10.5/15 tires. Only had to bash the pinch weld and trim the fender liner once I went up to 33x10.5/15

 

Oh I was referencing a different post about the door sill sticker- it sounds like your sticker is identical to mine.
That’s so odd. I wonder why I seem to be the odd man out here. I’m just gonna hammer the punch welds and chalk it up to extra beefy tires, but still puzzling.

 

did you have an alignment done when you got the new tires? if so the alignment settings can move the tire forward or back in the wheel well

 

That would be caster adjustment, right? My knowledge about alignment is very basic but I know the general terms and concepts. But no, I didn’t get it aligned after the tires. I had it aligned like 2 weeks ago because I knocked my toe out of spec in the desert. Pretty sure that alignment is under warranty though, I’ll give em a call and see what they think about tweaking it

 

yep, adding caster will push the tire forward some. do you have an alignment sheet with the before/after?

 

Somewhere around here, yeah. I’ll have to dig it up though, I’m pretty uh… bad with keeping up with paperwork. I thought on the first gen’s the caster and camber adjustment happen at the same bolt… I wonder if they’d be able to push the caster out far enough without throwing the camber out of spec. I unfortunately don’t have aftermarket UCAs, I was under the impression you only really need those at 3+” of lift

 

another important question, how does it drive? wheel return to center as youd expect?

otoh the rearmost alignment cam on each side affects caster much more than camber. even with stock control arms they should be able to push you to at least 2 deg of caster to keep the tires off the pinch weld while keeping good camber. factory arms should allow up to 3 deg caster or so which pushes the wheel as far forward as possible . if any of the cams are seized, which is common, it will throw a wrench into things and limit what is actually possible. Im far from an alignment master so maybe someone will chime in with better info (@Speedytech7 @Empty_Lord)

that said, if it drives fine, hammer the pinch weld flat and keep on keepin on

 

As stated above I would be suspect of caster being too close to 0. If it was lifted and they didn’t adjust it for more caster that wheel will be sitting further back than stock thus leading to rub even on stock sized tires

 

Thanks to both of you! To answer one of the questions, it drives just fine. No wandering or pulling or anything like that. The very recent alignment definitely happened post-lift (which was sometime last year, and have had 2 alignments since then) but I don’t know how close to 0 they set the caster. The alignment is under warranty so I’ll give them a call Monday and see what they can do.

 

My 96 4X4 lists 31 10.50 X 15 as an alternate tire size, yours sound 2 wheel drive to me.

 

Nope, 4x4. I’ll try to snap a pic of the sticker when I go out today. Replacing the fuel pump a bit later

 

Always ask for a printout of the alignment results. These typically contain the before and after specs. Post a photo of the results sheet here.