I've got a 91 runner. The rear sags so bad it's pitiful and the springs are really soft. 2 sacks of horse feed and it looks like I'm towing a house trailer. Yesterday I ran up on a deal on some really nice 15x10 aluminum rims. I had 'em put on, with my half worn 31x10.50's. Nice balloon effect on the tires, but it's only temporary. I want to make sure the suspension is right before I buy tires and have to deal with rub (I HATE rub). I don't do any trail riding or mud bugging. It's a farm truck and a baby hauler. I use 4wd just enough to need it and I do need the ground clearance.

I'm leaning towards 31x12.50 Pro Comps, and from what I've gathered from reading this site all morning, I should be good to correct the sag with a set of OME or Downey HD springs. My only question is, will these tires fit on the front, no rub, without a lift? I want the rear stiffer and taller, as it gets to pull a trailer from time to time, but I don't want or need an overgrown trail rig that my wife can't drive.

I'll only go to 33's if I can't get a decent price on the 31's, but I really don't like the ballooning of the narrower tires on these rims. The reason I'm even going down this road is to improve side to side stability, which is already improved somewhat by widening the stance. I'm hoping the rear springs and better shocks will also help in this area......

So, to repeat the question, will the 31x12.50's fit and if not, will anything need to be done besides a bit of trimming and pinch weld flattening?

 

FYI, It's not only the rim size, but the offset. Where along the centerline of the wheel the hub mounting surface is. Without knowing that i think it would be hard to tell.

 

Welcome to YT. Thanks for taking the time to read up on your topic. You have no idea how many people just ask how to fix their sagging rear end without doing any research. Anyways YES 31's will fit just fine on the front. In fact many 4-Runners came stock with them. You will be very happy after you replace the rear coils. New shocks all the way around will really improve your ride to. It's not too hard of a job but here's a link to a write up I did on how to replace your coils.

https://www.yotatech.com/forums/f128...4runner-76341/

 

It has 31's on it now, but they are 10.50. I was wondering about the 12.50's. I've got to replace a wheel stud today, so I'll measure the backspacing. I can tell you that there is a WHOLE lot of tire not in the wheel well, though.....

 

from the sounds of it your wheels have little backspacing (making them stick out further) the 31"s should fit fine from my knowledge and if you have to go to 33" a set of ball joint spacers up front will suffice 1.5" lift (possibly with some trimming and pinch weld flattening

 

Fitting a 12.50 depends on the backspacing of those wheels you put on.

 

The 31x12.5s ought be fine assuming the wheel backspacing is correct. If you want to run 33x12.5s without rubbing you'll been bj spacers a comparable rear lift, 1 in body lift, hammering the pinch weld and wheels with about 3.75in back spacing. Even then you might get a little rubbing at the extreme ends of the travel.

 

One way to visualize if the tires will rub or not is to turn your steering wheel full left or right, then go look at the clearance around the tires. 12.5" wide tire will extend approximately 1" inwards from the existing tire and 1" outwards.
I'd be more worried about the rears rubbing on the fender with some weight in the back and you hit a bump though.

 

I didn't replace that lug stud today, laziness took over, but I did take the wheel off and measure it. They measured at 15x10 with 3.75" backspacing.

 

Just as an FYI -

I installed the OME 2" springs rear and the SDORI 1.5" spacers up front and could not fit 31"x10.5"x15" Procomp AT Extreme on the truck with the stock wheels. That said the tires that are currently on the truck are Dunlop Radial Rover's @ 31"x10.5"x15" and they fit fine - just depends on the manufacturer.

The widest part of the tire up top hit the upper control arm because it is pushed higher (towards the wide part of the tire) by the bj spacer and my plans of new tires were sacked until I buy rims with different with an increased offset or spacers...

 

No they won't fit without rubbing.

Since you have such a wide wheel with so much backspacing, the tire will contact the inner fender pinch weld.

Most guys will just take a BFH and smash the pinch weld flat.

To run such a wide wheel, some lift is probibly going to be needed.

p.s who the heck put a 10.5" wide tire on a 10" wide rim!!

 

I predict massive rubbing in the lower part of the front fender wells during turns. Judging by the comment about how there is "a WHOLE lot of tire not in the wheel well" I'd say you will rub pretty bad in the rears every time you hit a bump in the road.

 

A local mom & pop shop mounted the tires. They actually look pretty decent. A lot better since the running boards came off. I haven't done much with the old girl since this post. Matter of fact, she sits now with a for sale sign to raise some much needed funds to repair my old pickup.