Going Bigger - 5th Gen Tire Fitment Guide

So I read the chart and it's still unclear if I can fit 285s on the truck without rubbing. The chart doesn't specify if the TRD Pro model. Is it true that the Stock TRD Pro is lifted 1 inch higher than the other models? Has anyone put some KO2 on their stock TRD Pro without any rubbing.

TIA

People run 285s on stock TRD Pro wheels all the time but they generally run wheel spacers. The TRD Pro sits .75" higher in the front than other models, no difference in the back. Rear springs in the pro are the same as every other model, only difference is the shocks.
 
People run 285s on stock TRD Pro wheels all the time but they generally run wheel spacers. The TRD Pro sits .75" higher in the front than other models, no difference in the back. Rear springs in the pro are the same as every other model, only difference is the shocks.

So I DO need some spacer for the KO2s not to rub?
 
So I DO need some spacer for the KO2s not to rub?

Maybe, maybe not. Every vehicle is different. Keep in mind when you run wheel spacers you're pushing the tire out which then created other clearance issues. You may clear the control arm but then cause body mount rubbing. There is literally no way to be sure until you mount them up and test fit them. The KO2 runs small in the world of 285s though so you have that working in your favor.
 
I’m confused

I just need a simple yes or no. :( I’ve looked at this chart, read the article about backspacing and offset and still don’t know much. But yell at me if you have to—but will these fit my stock 2015 4Runner without any problems.

Fallen Wildpeak

LT275/70R17 C 114/110S approved rim width 7.0 - 8.5 8.0 diameter-32.4 overall width 10.8

TRD 17” wheels

Thank you.
 
I just need a simple yes or no. :( I’ve looked at this chart, read the article about backspacing and offset and still don’t know much. But yell at me if you have to—but will these fit my stock 2015 4Runner without any problems.

Fallen Wildpeak

LT275/70R17 C 114/110S approved rim width 7.0 - 8.5 8.0 diameter-32.4 overall width 10.8

TRD 17” wheels

Thank you.

Anyone that yells at you can take a walk. We're all here to learn, none of us were experts on our first day. That being said, there is no simple yes or no, that's the point I'm trying to make. 275 absolutely will fit on a completely stock 4Runner but you might have a little rubbing on the front bumper. It's actually very likely you will have a little rubbing on the front bumper. It's very likely even a stock size 265 will rub on the front bumper. This is due to the OEM 265 being TINY and no where near the size of any other 265 on the market. If you do rub, and you likely will, all you need to do is unbolt the plastic fender liner, push the liner forward, bolt it back in, and trim the lip off the lower inner edge of the plastic front bumper skin. Literally two 10mm bolts on each side, it'll take you 30 minutes said and done since you want to take your time while trimming. It's a super simple mod that 95% of us have done due to rubbing. Believe it or not, most TRD Pro models are trimmed at the port because the stock size tires used on the Pro rub the bumper.
 
Anyone that yells at you can take a walk. We're all here to learn, none of us were experts on our first day. That being said, there is no simple yes or no, that's the point I'm trying to make. 275 absolutely will fit on a completely stock 4Runner but you might have a little rubbing on the front bumper. It's actually very likely you will have a little rubbing on the front bumper. It's very likely even a stock size 265 will rub on the front bumper. This is due to the OEM 265 being TINY and no where near the size of any other 265 on the market. If you do rub, and you likely will, all you need to do is unbolt the plastic fender liner, push the liner forward, bolt it back in, and trim the lip off the lower inner edge of the plastic front bumper skin. Literally two 10mm bolts on each side, it'll take you 30 minutes said and done since you want to take your time while trimming. It's a super simple mod that 95% of us have done due to rubbing. Believe it or not, most TRD Pro models are trimmed at the port because the stock size tires used on the Pro rub the bumper.

Thank you so much for a great answer. My son (who has a great looking 4th Gen) is encouraging me to go with more aggressive tires.

I had a 3rd Gen for 18 years! Loved it! But sadly, after many rust repairs and frame welds, it was done. Sold to kid for a project vehicle. I really miss it.

Thanks again!
 
I want to see who's running a 35x1250R17 without a body lift or tires outside of the wheel well.



I’m running 35x12.50x17 Toyo MT. No spacers. SCS wheels. Lots of trimming. Aggressive BMC. High clearance front bumper mod.

There’s also a guy running 37’s that wheels harder than 99.9% of people on here.


35’s are doable. It’s if you’re willing to do the work to make it fit that makes people not do it. Mines a 2014, not a 2020. I don’t mind doing the necessary work.


Sent from my iPhone using Tapatalk
 
I’m running 35x12.50x17 Toyo MT. No spacers. SCS wheels. Lots of trimming. Aggressive BMC. High clearance front bumper mod.

There’s also a guy running 37’s that wheels harder than 99.9% of people on here.


35’s are doable. It’s if you’re willing to do the work to make it fit that makes people not do it. Mines a 2014, not a 2020. I don’t mind doing the necessary work.


Sent from my iPhone using Tapatalk

I'll check your post history. I know about General Overland but definitely do not want that stance. This 4Runner is only 2 months old but not afraid to go to work. Fit 37s pretty well on my 3rd gen

bvBbjEg.jpg
 
So I DO need some spacer for the KO2s not to rub?

A few quick things here.
1) Wheel spacers will make rubbing happen and worse if it already occurs.
2) you can run 285/70/17s on a stock sr5 suspension if you push your fender liner forward, but you will have some rubbing in reverse when turning. With a pro that is slightly lifted in front, the fitment may eliminate the rub. fine to float you until the next mod.

so yeah a pro would fair better with 285s than other models when you're talking stock. otherwise, bmc and or lift.

right now i have the same 285s with a 3" in front, spidertrax wheel spacers and a bmc... zero rub.
 
If it fits with a lift - it also fits without a lift. The lift does nothing for fitment in the front. So... yes 285's should fit with the correct wheel offset up front without a body mount chop. That said - all 4Runners are slightly different, so it will somewhat depend on the tire you select and vehicle variation. I don't think any 285 tire I'm aware of is larger than my 275/60/20 street tire set (33.0 height and actually wider than either set of 285's I've had), and they did not require a BMC, but did require removing the mud flaps and trimming the front bumper area.

285/75/17's - those require a BMC no matter what. Stick with a OEM-ish offset and you should be fine with 285/70/17s. Lift or no-lift.

I seem to recall reading that pushing the tire forward in the alignment will help. Can you shed any light on what that is and how it helps?
 
I'll check your post history. I know about General Overland but definitely do not want that stance. This 4Runner is only 2 months old but not afraid to go to work. Fit 37s pretty well on my 3rd gen



bvBbjEg.jpg



Also look at the 285/75/17. About a 34x10.5. I had wheel spacers and it made it worse so I removed them.

There’s a spot where the fender attaches where the mud flap is that’s definitely in the way. If there was a way to just bend it out of the way or tac weld it to the body that’ll make more room.

Up travel, especially at a higher speed will be an issue regardless. There’s just no where for the tire to go. Most of my plastic liners are gone but it still poses an issue.

Let me know if you need pics of where I trimmed or anything


Sent from my iPhone using Tapatalk
 
I seem to recall reading that pushing the tire forward in the alignment will help. Can you shed any light on what that is and how it helps?

The main rub point that starts to drive more significant adjustments is the body mount area. It's on the rear side of the fender well area below the firewall. Moving the tire forward will help it stay away from that area where it will rub. The lower control arm is adjustable to set caster and camber in the front alignment.

You can set the lower control arm to the maximum amount of caster and the result of that will be to move the lower ball joint as far forward as you can while still maintaining proper alignment. The result of that adjustment gives you a bit more clearance from the body mount area. To put that in numbers, 1 degree of additional caster adds roughly 0.5cm of forward movement. Keep in mind that a 1" increase in tire height results in 0.5" increase in radius. So if you could go from 2.5* of caster to 4* of caster, all else equal, you would have room for an additional tire height of roughly 1.5 cm. About half an inch.

Does that solve the problem? Sometimes it does. The reason being that there's some spare room to start with. So if you started with 1cm of spare room and you're going up to a 285 tire size (roughly 1.5" taller) you'll rub on the rear side of the fender area. (the 1.5" height addition = 1.27cm of increased size on each side) so it'll rub a bit. If you then were to add 1.5* of extra caster, you'd then add 0.75cm of extra room. Now your taller tire doesn't rub. So if it's just lightly rubbing - adding a bit of caster can help solve it.

Hope that helps. It's not a solution for everything. And some vehicles don't have enough extra adjustment range in the alignment to do that. But for some people it works.
 
The main rub point that starts to drive more significant adjustments is the body mount area. It's on the rear side of the fender well area below the firewall. Moving the tire forward will help it stay away from that area where it will rub. The lower control arm is adjustable to set caster and camber in the front alignment.

You can set the lower control arm to the maximum amount of caster and the result of that will be to move the lower ball joint as far forward as you can while still maintaining proper alignment. The result of that adjustment gives you a bit more clearance from the body mount area. To put that in numbers, 1 degree of additional caster adds roughly 0.5cm of forward movement. Keep in mind that a 1" increase in tire height results in 0.5" increase in radius. So if you could go from 2.5* of caster to 4* of caster, all else equal, you would have room for an additional tire height of roughly 1.5 cm. About half an inch.

Does that solve the problem? Sometimes it does. The reason being that there's some spare room to start with. So if you started with 1cm of spare room and you're going up to a 285 tire size (roughly 1.5" taller) you'll rub on the rear side of the fender area. (the 1.5" height addition = 1.27cm of increased size on each side) so it'll rub a bit. If you then were to add 1.5* of extra caster, you'd then add 0.75cm of extra room. Now your taller tire doesn't rub. So if it's just lightly rubbing - adding a bit of caster can help solve it.

Hope that helps. It's not a solution for everything. And some vehicles don't have enough extra adjustment range in the alignment to do that. But for some people it works.

Excellent explanation!
 
I'll check your post history. I know about General Overland but definitely do not want that stance. This 4Runner is only 2 months old but not afraid to go to work. Fit 37s pretty well on my 3rd gen

bvBbjEg.jpg

The easiest (not cheapest) way to jump to 37's is to use Marlin's setup. They relocate the front spindle forward about 2". Solves all the rubbing issues. And you can upgrade to a much heavier duty steering rack that you'll probably want if you're doing that.

This is what I would do to go to anything over 35's. For a narrow track with 35's I'd custom modify the OEM LCA's to move the spindle forward 1" and run everything else in stock location. If search I've posted drawings of how you could swap the ball joint forged assembly left to right on the OEM LCAs and achieve approximately 1" of forward relocation that should be enough to clear 35's without body chopping.

rclt-hd-pre05t.jpg


And the ground clearance is ridiculous. It almost needs a portal rear axle to be complete:
mike-czajkowskis-2016-ifs-tacoma-rock-crawler-2018-09-17_22-15-08_622130.jpg
 
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I've been following Big Mike's Taco build and what he's been able to do their RCLT setup is pretty insane. I don't know if he's gotten his setup to stop eating CV boots yet or not. Pretty freakin cool tho.
 
The main rub point that starts to drive more significant adjustments is the body mount area. It's on the rear side of the fender well area below the firewall. Moving the tire forward will help it stay away from that area where it will rub. The lower control arm is adjustable to set caster and camber in the front alignment.

You can set the lower control arm to the maximum amount of caster and the result of that will be to move the lower ball joint as far forward as you can while still maintaining proper alignment. The result of that adjustment gives you a bit more clearance from the body mount area. To put that in numbers, 1 degree of additional caster adds roughly 0.5cm of forward movement. Keep in mind that a 1" increase in tire height results in 0.5" increase in radius. So if you could go from 2.5* of caster to 4* of caster, all else equal, you would have room for an additional tire height of roughly 1.5 cm. About half an inch.

Does that solve the problem? Sometimes it does. The reason being that there's some spare room to start with. So if you started with 1cm of spare room and you're going up to a 285 tire size (roughly 1.5" taller) you'll rub on the rear side of the fender area. (the 1.5" height addition = 1.27cm of increased size on each side) so it'll rub a bit. If you then were to add 1.5* of extra caster, you'd then add 0.75cm of extra room. Now your taller tire doesn't rub. So if it's just lightly rubbing - adding a bit of caster can help solve it.

Hope that helps. It's not a solution for everything. And some vehicles don't have enough extra adjustment range in the alignment to do that. But for some people it works.

Gosh I wish I measured more before hand but this should be super helpful. I’ll keep y’all posted. Thanks man!
 
Gosh I wish I measured more before hand but this should be super helpful. I’ll keep y’all posted. Thanks man!

The problem is that every 4Runner is a bit different, so even if you had measured before, you wouldn't necessarily know for sure if your adjustments for caster would have enough left to help. So it really is one of those situations where you kinda have to just try and see if it fits.

To add another wrinkle - the higher you lift, the less caster you have. It's just the way the geometry of the A-arms work where the upper control arm pivots at an angle compared to the lower one. So... the lift height will have an effect on the measured caster angle even if the lower control arms is all the way forward. For example at stock height the same LCA settings for 4* of caster would only result in about 1.5-2* of caster at 3" lift. What that means for this situation is that you can't necessarily just assume that if you're set at 2* of caster now, you can go to 4. There might not be enough adjustment left. And the caster angle doesn't really directly translate to whether the spindle is adjusted forward. It can be all the way forward at 2* of caster in some cases and in others that would give 5* of caster.

That's why most lifts end up with replace upper control arms. They move the upper ball joint to get back the lost caster from the lift. BUT... they do it by moving the upper joint to the rear - effectively removing some of your clearance at the body mount area. So the need for upper control arms to have a good allignment can end up reducing your body clearance where you want it.

All of those factors plus a very close fit result in a lot of confusion over whether a certain tire size fits or not. And that's kinda why we always end up with the answer being - maybe, maybe not - depends on your vehicle. How much lift, what control arms, what wheel offset, what tire size, and even what tire tread pattern - some are just a bit wider than others.

I think you can pretty safely assume on most 4Runners that 285/70/17's will fit with trimming the front bumper and removing the mud flaps as long as your wheels are stock offset. Wider offset causes problems and so do larger tires. You can pretty safely also assume that 285/75/17 being 1.3" taller than 285/70/17's will not fit in almost any instance without cutting the body mount. On mine it was not close to fitting. Other sizes like 255/80/17 being narrow tend to fit better than wider ones, so you could have a bit wider stance on the wheels.

And - finally, I think we all dream of a day when we can just slap 35's on without a lift or rubbing like the JL wranglers. Come on Mr. T - give us some tire clearance in the next edition!
 

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