Considering 35s? 34s? 33s? 32s Here's some tech info for you...

Sal R.

Very Well-Known Member
Apr 6, 2017
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San Diego
This thread is meant to provide some general information regarding some things to consider when adding larger than stock tire sizes and/or aftermarket wheels with specs different stock.

Here is a general infographic of where interferences will occur with the addition of larger tires/varied wheel offsets:
backspace.jpg

First, let's talk suspension and suspension lifts. The suspension is meant to go up and down and are designed to have a max upward travel distance and downward travel distance. OEM tire sizes are designed to clear all the surrounding suspension components and structure at full compression steering lock to lock. The bumpstops located just above the lower control arms are the absolute limiting component of suspension upward travel.

While suspension lifts (strut spacers, spring/strut combo, coilovers, etc.) are an easy way to gain some clearance between wheel & tire and the surround components and structure AT static ride height, it does nothing for clearance when the suspension cycles upward completely. You'll still get the same max allowable upward travel with stock suspension with all the same interferences from lock to lock at full compression. And when you're off-roading, your suspension WILL cycle upward all the way.

Naturally, when putting on larger tires, you are effectively reducing the amount of clearance between the tire and the suspension components, fender, inner fender liner, firewall, and frame. How much reduction in clearances that will occur depends on the wheel AND tire combination. And I say wheel AND tire because the specs of the wheel will determine the placement of the tire at static ride height and the tire specs affects the steering turning travel area that is covered from lock to lock.
OEM-LargerTires.jpg

The two characteristics that determine wheel & tire placement are wheel backspacing and wheel offset. The lower the backspacing, the more the wheel & tire is pushed AWAY from the wheel hub (wheel sticks out more). The higher the negative offset, the more the wheel & tire is pushed AWAY from the wheel hub (wheel sticks out more).

Low backspaced and high negative offset wheels create clearance away from SOME surrounding components and structure, but effectively, it only moves the interferences to another location.

Wheel spacers reduces wheel backspacing (e.g. 4.5" backspace + 1.25" wheel spacer = 3.25" backspace).
wheeloffset.jpg

Body lifts create vertical clearance by lifting the actual sheet metal body AWAY from the frame and suspension.
bodylift2.jpg

To create clearance for larger tires using a body lift, a good rule of thumb is 1in for every 2in tire diameter change (e.g. OEM 30s > 35s = +5in diameter change ->2.5-3in body lift).
 
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Sal R.

Very Well-Known Member
Apr 6, 2017
311
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San Diego
For reference, 265/75R16 (31.25" Tire) 1" from full compression:

Based on measurements taken when I tubbed for 34s, the wheel upward travel has a ratio of 2:1. Basically, for every 0.5" of travel between the lower control arm to the bumpstop equates to 1" of upward travel at the wheel.

In the pic below, I still had +2" of usable upward wheel travel before fully cycling the suspension.
IMG_20170503_093844.jpg
 
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Sal R.

Very Well-Known Member
Apr 6, 2017
311
177
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San Diego
For reference: 295/70R18 (34" Tire) 0.5" from full compression

Based on measurements taken when I tubbed for 34s, the wheel upward travel has a ratio of 2:1. Basically, for every 0.5" of travel between the lower control arm to the bumpstop equates to 1" of upward travel at the wheel.

In the pic below, the wheel can travel upward +1", but as you can see, it would interfere with the fender.
IMG_20170503_094311.jpg
IMG_20170503_094338.jpg
 
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1down4up

Active Member
Jan 13, 2017
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Just installed some new shoes on the tree. 275-70/17. Fitment is pretty much maxed for tire size. Stock suspension with rear airbags. Just an addition to the thread!
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Jason Schweitzer

New Member
Feb 18, 2018
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If like a 2 inch or 3 inch. What is the best way to do this. I' like to run 33s on 18inch wheels.
 

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Sal R.

Very Well-Known Member
Apr 6, 2017
311
177
43
San Diego
To add to this thread, Jose Wong over @expo has a detailed thread regarding tubbing for 35s.

Wheel spec is OEM LC80 wheels with spacers resulting in a 3.25" backspace. This kind of wheel spec results in a lot of material removed to clear 35s stuffed, lock to lock.

d53bf662cfa8a11084b89d0921f3212d.jpg

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IMG_20180517_142448.jpg
 

Sal R.

Very Well-Known Member
Apr 6, 2017
311
177
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San Diego
So, what will it take to clear 35x12.5 tires?

In short:
  1. Wheel must have a minimum 3.5" backspacing to clear the UCA, regardless of wheel width.
  2. Cut away firewall or a 3 inch body lift or a combination of both.
  3. Body lifts will require:
    1. Clearancing the transfer case shifter opening, if you have one.
    2. Moving the front and rear bumper crash bar support upward, which will require cutting and welding
    3. Extending the steering shaft, which require cutting and welding.
  4. New wider fiberglass fenders or trimming the OEM fenders 3-4" to clear the tires.
  • Not an issue if you use a bodylift.
 
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mnwanders

New Member
Feb 9, 2017
18
3
3
48
Just installed some new shoes on the tree. 275-70/17. Fitment is pretty much maxed for tire size. Stock suspension with rear airbags. Just an addition to the thread!
74312701bcd6f5dbf352a0734203fc10.jpg
2de935390ca38ac6b0eccc4407acdc46.jpg
5df2b462f1f2853e78ebedfdb0784c04.jpg
806cdba289247928d12d4d6d178ca449.jpg


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So the big question I have after seeing this is, did you go to 275-70/17 for the spare too? If you did, how does it fit in the traditional spare spot? Does it fit ok? I'd like to go to this size but I was concerned about the size of the spare.
 

1down4up

Active Member
Jan 13, 2017
23
7
3
32
So the big question I have after seeing this is, did you go to 275-70/17 for the spare too? If you did, how does it fit in the traditional spare spot? Does it fit ok? I'd like to go to this size but I was concerned about the size of the spare.
Honestly... I didnt do the spare. Still factory . Sorry cant help with that

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mnwanders

New Member
Feb 9, 2017
18
3
3
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One more question...I'm heading out west in a few weeks for hunting and I often hear guys say that they recommend 10-ply tires. Are any of you running anything above SL? I will probably put some new tires on here before heading out and was curious about the load range you all use. I was looking at putting on some 265/70/17's to ensure they fit and get load range E tires, probably KO2s or Yokohama Geolanders. Any thoughts on load?
 

spacecruisers

New Member
Dec 10, 2018
3
0
1
35
I'm wondering this too. Did you ever find out if it works? I'm looking into some new tires for my Sequoia and am thinking of going with 285 70 17. Previous owner had Rancho (quicklift?) shocks installed and a spacer lift in the rear so I'm hoping to fit that size all around.
 

GTV

Active Member
Dec 5, 2018
32
8
8
43
I haven't tried personally but I've heard it fits if you deflate it a bit... but what good is that?? 275/70/17 (32") will fit.