2021 4Runner Build

Hey all,

This looks like a good site to document a 4Runner build so here it goes…

I was not looking for a 4Runner but ended up with one and now I’m glad I have it. For the last 24 years I have been building and wheeling a little Jeep TJ. It is an awesome rock crawler but not good for venturing further afield. Living along the Colorado front range my typical adventures are within a days drive west of here, places like Moab or the San Juans. I realize the 4Runner will never be a rock crawler but will be a great overlander for going further afield in luxury to wheel moderate to slightly difficult trails. I know I will never take it on trails like Pritchett Canyon, but there are plenty of very scenic easier trails all over the US.

So here’s my goal: Build a capable 4Runner to handle easy to moderate trails based on the experience gained from building a Jeep. And then of course if things go well, continue to build and make it more capable. This becomes quite an addiction.

1. Weight/Power: The first thing I learned was each pound you add makes the vehicle less powerful. You don’t want to add so much weight that you end up in the slow lane with the semis trying to get over the continental divide.
2. Center of Gravity: Keep the center of gravity as low as possible. Only lift the vehicle high enough to fit the tires. Load camping gear as low as possible.
3. Reliability: Avoid modifications that compromise reliability. No one want to be the guy that always breaks down on the trail. The 4Runner sounds like a very reliable vehicle, so don’t screw that up.
4. Armor: Add the required amount of armor to keep you going up the trail without breaking things but not the unnecessary stuff that just adds weight. There is nothing wrong with an aluminum skid plate, I have been running one on the Jeep for decades. Of course it’s hard to bang the skid plate on a short wheel base Jeep with large tires. This 4Runner is a different story. Crawling underneath there is a lot of exposed stuff that needs protecting. I see a really long skid plate set-up in my future.
5. Articulation: OK, so these things don’t seem to have much articulation given the IFS. There appears to be a few things that can be done but to improve articulation but you still end up measuring articulation in inches versus feet. My Jeep ramps at over 1300 which is a sick amount of articulation. I will do what I can but will probably have to learn a different style of wheeling, with one wheel in the air. The vehicle does have plenty of electronic assist gismos such as A-Trac and crawl assist. This seems to be the new wheeling reality with IFS. I am used to old school wheeling; airing down the tires, modulating the throttle to keep up momentum without spinning tires too much and then locking up the axles when all else fails.
6. Approach/Departure angle: It looks like you can make the front very respectable, but the rear is another story. That spare tire hanging down in back has to go.
7. Recovery: A winch is a must, hi-lift jack, straps, etc.
8. Cargo: The ability to organize all the camping gear without stuff flying around.
9. On-board Air: Always a must. Airing down the tires gives you triple the amount of traction.

Completed Mods:
1) Power: Added K&N Intake, Magnaflow cat-back exhaust and Banks Pedal Monster.
2) Lift & Tires: 2" lift, Dr KDSS parts, 285 70r17 mud terrain tires.
3) Clearance: Viper cut, windshield wiper bottle relocation.
4) Traction: ARB On-board air compressor.
5)


Here is the back story of how I got a 4Runner. During the pandemic my wife’s papa was going downhill fast and he wanted to buy each of his kids a new vehicle before he passed. He was a Marine who did many tours in Nam and got cancer from agent orange. My wife was driving an old Xterra. She liked that it was boxy and you sat up high. I showed her many SUVs on-line and she really liked the boxy look of the 4Runner. We went to the dealership and the lot was mostly empty. They showed us a few used 4Runners and one smelled sickeningly sweet. What nasty odor were they trying to cover up? At that point she said new or nothing. We went back inside and the manager came over and said he had only one new 4Runner in stock (thanks to the pandemic). The mechanics had it in the back adding a lift to get more profit from the one vehicle they had to sell. Without the black out badging, skid plates and running boards installed they let us test drive it. They had to find a step ladder for my wife to get into it, a good sign. Once I drove it I knew I had to convince her this was the vehicle she wanted. You sat up high, it was boxy, perfect vehicle for her.

Once we got it home I had to figure out how she could get into it without a step stool. I found these AMP Research running boards. They tuck under and when you open the door they drop down. This would not have been my first choice of running boards and violates the weight rule but now I really like them. They allow our elderly parents to get in and out. She drove it for the first 3 years and then declared she didn’t like it anymore. It was too large, hard to get into and she was going to trade it in. What? Are you crazy? I told her we would trade in my old daily driver and I would take the “TRD” off her hands. She ended up with a new RAV4 and I ended up with the 4Runner. I think I got the better end of the deal.

So this is my starting point. The lift appears to be either a 2” or 2.5” lift. It has all the off road Toyota gismos such as KDSS, rear locker and crawl assist. The wheels are Toyota TRD 17” rims with Nitto Trail Grappler M/T 285/70r17 which translates to roughly 33” x 11.5”. Not huge tires but a good start. This was the tire size I started with on the Jeep before re-gearing for larger tires.

 

The first upgrade is more power. Every 4x4 I have owned gets a new air intake and cat back exhaust. I am sold on K&N so I ordered one. They come with either a plastic or aluminum intake tube. I splurged and got the aluminum intake. This fits perfectly into my build criteria. The old plastic monstrosity that was removed was surprisingly heavy. The new one weights about the same so you get more power with not much weight gain. K&N advertises a horsepower gain of around 12 to 15. The torque numbers are a bit larger. You can feel the little bit of gain and it sounds more throaty when accelerating. Every little bit helps when you are adding more overall weight. The other impressive thing was when the kit arrived I inventoried the parts and discovered a small bracket was missing. After calling tech support they asked for the serial number of the kit and then sent out the replacement part. Three days later a box arrived and it contained a new bag of all the small parts. So now I have plenty of spare parts if anything breaks. I have been running K&N on the Jeep for decades and have not had a single issue. Since the filter is reusable and only needs cleaning once every 100,000 miles (more if you do dusty off-roading) you should make back some of the money by not having to buy those paper filters every 25,000 miles.

There are plenty of build logs and videos on-line so I won’t do a build log but I will mention two things I did not see in anyone else’s videos. The first is the horn. The instructions say to remove the bolt holding it on and replacing it with the provided rubber bushing on a bolt. This sandwiches the horn between the new box and the side of the engine compartment. I didn’t like that solution. Fortunately there is a stock bolt hole (same size) about 6” further back. The old location has a hole above the bolt hole. The horn bracket has a tab that fits into this hole. The new location does not have this hole so I simply bent this bracket tab up and moved the horn to its new location. Fortunately the wire was long enough. In the picture below you can see the new box at the bottom of the picture and the horn in the middle. The horn itself is black so it’s somewhat hard to see but the bracket with the bent up tab is clearly visible.


The other issue relates to one of the other rubber isolators. It mounts in a stock hole not used by the stock air box. At first the rubber isolator did now screw all the way in. Upon removing it I could see something blocking the hole. With a small screw driver I was able to push through the obstruction. It felt like something plasticy. Looking at the underside of the wheel well it became apparent that Toyota sprayed the inside of the wheel well with some sort of rubbery substance to resist rust or reduce road noise, not sure…. To fix this I took one of the old bolts and screwed it in so it broke through this layer and cleaned out the threads. Now the rubber isolator bolts right in.


Here are before and after pictures. I give this kit and the results two thumbs up, a really good start. Now it’s on to a cat back exhaust.

 

Installed a Magnaflow Overland cat back exhaust. It was really easy to install. You can see the old stock muffler beside the new muffler. The new one is smaller and lighter. More power, less weight, headed in the right direction. I got this one because the exhaust tip ends just past the tire and not extending out under the rear bumper. I used to wheel an old full size Bronco and that was the first trail damage. There's a whole lotta plastic still hanging down back there. That will be the next to go.

 

Just installed the Banks Pedal Monster. WOW!!! That is what this beast needed. No more spongy pedal. Even in the City mode with the fine tuning set half way up it now feels like it should have felt from the factory. I know it does not provide any more power but it sure feels like it has more power. Toyota derated the crap of it probably so they could claim better gas mileage. You don't buy one of these for gas mileage. Only time will tell how all these mods affect the gas mileage but I expect it to go down a bit. At this point all I know is the vehicle is now fun to drive. Now on to off road upgrades...

 

K&N advertises a horsepower gain of around 12 to 15 ----- WOW, hope you don't really believe that!

K&N advertisers left out *Lots more dirt to the cylinders

 

Why go & shit on this dudes parade... smh... ----- WOW

 

I don't believe the horsepower gains just like I don't believe Toyota's MPG claims. I use the sock covers for added dirt protection. This one has been on my old TJ for over 100,000 miles, at least half of those hard off-road miles since it's not my daily driver. No engine issues so far.

 

I didn't shit on the dudes parade... smh... ----- WOW, as you so eloquently pointed out.
Don't melt.

I was being real. Get over it.

 

lol u 100% were trying to

have a good one lad

 

Ok, whatever you think.......

 

Love this thread. Thanks for sharing and posting. I have done something similar but never got around sharing it with folks like you are doing here. Well done.

 

Saker, thanks for your honest opinion. Ziva, thanks for defending me. ChessGuy, thanks for the praise.

There are so many ways to transform this vehicle. Each person has to decide what parts are right for them based on what type of wheeling they are going for. Hopefully someone out there will benefit from what I am doing. Probably the most important thing I have learned from 40+ years of wheeling is make sure your rig is overbuilt for the trail you are on. You don't want to be the guy that is always breaking down and getting stuck.

 

Question, why just the muffler and not a catback with a muffler to improve more flow?

 

Sympley76: From what I understand a cat-back exhaust system includes everything beyond the catalytic converter which is usually the muffler and the exhaust pipe. I did not consider replacing the catalytic converter. They are fairly pricey. On my Jeep I did replace the exhaust header. Those are usually the next most restrictive part of the exhaust. What I am looking for is a little more power to offset the weight being added while trying to keep things as stock as possible for reliability. If you really want power, add a blower.

 

What kind of roof rack to install? That depends on your specific needs. My biggest need is to transport canoes and kayaks I make and paddle. That and hauling wood back from the lumber yard. What about camping gear? I try to keep the center of gravity as low as possible, so the gear goes inside. The 4Runner is so cavernous inside if I fill that up and need more room on top I better rethink what I'm bringing.

Then there is the roof tent I see on most roof rack sites. Having grown up along the gulf coast and camping at least once a month there were many times when we were flooded out. I could see getting a roof tent if I lived down there. But what about camping out West? If you camp in an arroyo a flash flood would be life threatening, camp on higher ground. The only real weather issue is high winds. The last place you want to pitch a tent in a wind storm is on top of a vehicle. So no roof tent for me. BTW, I finally learned after 50+ years of camping the secret to a good nights sleep, a 4-season hammock. I can sleep right through a rain storm, snow storm and high winds. No more looking for a flat piece of ground to sleep on. All you need to set up the hammock is two trees or in treeless places like Moab I string the hammock between two jeep, just tie it off to the roll cages. I even take the hammock backpacking.

All I really need is a pair of cross bars with good attachment points. I found these at Victory 4x4. I decided on these because they make one of the two rear bumpers I am considering and I wanted to check out the quality. They are strong, well made and only weight 7# each. You can slide them along the rails. I have them as far out as possible to stabilize the boats.

 

why is that changing original parts for aftermarket parts called "build" ?

 

The first thing I did was research and document all the additions I plan to make. Once you lay out all the upgrades you realize the electrical portion of the build is important and needs to be thought out. Instead of adding a bunch of fuse taps to the fuse box, a new fuse box for all the accessories is a much cleaner way to go. In my old Jeep I added one of these Painless Wiring fuse blocks 20+ years ago. These are quality products that have given me no issues. I chose the one that has three constant fuses and four ignition switched fuses. Just waiting for it to arrive, then I need to figure out where to mount it. I am leaning towards under the drivers side dash where the switches will go. When I installed this in the Jeep I snaked about half of the wires back out into the engine compartment. If needed inside I just pull them back. Each wire is clearly labeled down the length of the wire so you aren't having to figure out which wire goes to which fuse.

 

As I mentioned up front, the Toyota dealership had installed this lift, genuine Toyota, before selling it to get more $$$ during the pandemic. The salesman went on and on about how their shop is the best lift install shop in the entire state! I didn't trust any of that BS so I crawled underneath and noticed the rear is a standard 5-link suspension. They did not add a bracket to raise up and level out the pan hard bar. Without this bracket the axle goes a little off center. Not as much as my jeep with a 4" lift but it still needs to be corrected. That and from other people's install videos I see where the sway bar, without drop inserts, will hit the pan hard bar. Here is the before and after pictures. I would rate the dealership an A+ for salesmanship BS and a C- for knowing how to properly lift a vehicle...




Now on to the front axle...

 

Here is the Dr KDSS plates installed on the front sway bar. In the first picture you can see how the sway bar is pinching the bushing and the bracket is not square to the bar. In the after pictures the bushing is not pinched and the bracket is squared up. That should pretty much fix up the suspension issues.
.

 

If you made these, they are absolutely beautiful! You are a very skilled craftsman.

I can 100% recommend the Banks Pedal Monster. The K&N and muffler.... well I have nothing positive to say, BUT I do appreciate you sharing pics of your mods.

For electronics, I like to use blocks with covers like these

 

Thank you. Yes I make those boats. A lot of cutting small strips of wood and gluing them together. It is the epoxy coated fiberglass mat that gives it the strength. The wood is just for looks.

I really like the Pedal Monster. It doesn't add any more power but it make it much more drivable.

Not every upgrade is for everyone. There are an infinite number of build possibilities. Everyone has to decide how they are going to build their 4Runner based on their needs. Since I have the Jeep which is a monster rock crawler I plan to build this as a luxury camper (compared to a Jeep) that can wheel the mild to medium trails. I am always impressed when someone builds one of these to do the hard trails. I know what it takes to do that build. I would scrap the crappy front IFS and go with a 4-link solid axle because I don't like fixing breakage on the trail. The rear axle is impressively strong and already has a locker. For the Jeep I scrapped the crappy stock axles and went with a pair of Currie built Ford 9" axles with air lockers, high pinions, welded on differential skids and lower gearing. Currie runs these axles on their competition vehicle, the Fire Ant. I also went with an Atlas transfer case with lower gearing which is strong enough to run behind a V8 with 40" tires. A low gear ratio around 80 seems just about right for crawling. What works for me is build strong, keep the center of gravity low and the weight as light as possible. That and an electric cooler would sure be nice.

 

Viper Cut: My eventual goal is to put in a high clearance winch bumper, but for now a viper cut is a good start to start removing useless plastic hanging down way to far. This seems to be the most popular DIY fix given the sheer number of how to videos. The best advice from one of the videos is start with a mild cut and if you want then go higher. You can always cut more but you can't add back material. He also suggested if you are not familiar with the cutting tools then start with test cuts on the area to be cut off to get a feel for the tool.

Once you get the plastic off you will find the windshield washer bottle hanging way too low. Some companies sell yet another skid plate. I say better to move the bottle up higher and not have yet another skid plate to bang on a rock. There are a whole bunch of companies that sell these bottles. Most of them seem to put the bottle in the engine compartment above where the old one was. As you can see in the picture below I do not have enough room there for a bottle so I picked one that goes on the outside of the radiator and bolts to the bracket that holds the top crossbar. It's also the one suggested for the front bumper I am considering.


So the one I selected is from Snowbound Customs. It is rather expensive but is really well made. Unfortunately when I got it bolted in the passenger top radiator mount would not fit back on. Here you can see the bracket is too high by a bit over half a bolt width.


At this point I took the entire plastic front end off for better access. I measured straight down from the two outside holes and drilled small pilot holes. For the middle hole I took a piece of paper, marked the middle hole on the paper, transferred that to the bracket, then drilled out the holes with progressively larger drill bits.


Here are several pictures of the bottle in place.

 

Here is the Viper cut and the passenger side without the wiper bottle. The pile of useless plastic is starting to grow...

 

ARB Air Compressor: Airing down tires is a great way to get added traction, especially on rocks which is what I mostly wheel. They say it adds up to 3 times the traction depending on how low you go. You don't want to go too low without bead lock rims which are usually illegal on streets. I usually air down to about 15 psi. I went with the ARB twin compressor, the Rago mounting plate, a Slee relocation bracket and the Wifey system that lets you air up/down all 4 tires at once. All of this is documented in another thread: https://www.4runners.com/threads/rago-air-compressor-mount-doesnt-fit-2020-or-newer-4runners.38435/

Bottom line: Even though I had to do some cutting on the Rago plate, everything else went smoothly and the system works great. Airing down all four tires from 39 psi to 20 psi takes 2:20 minutes and airing up took just over 4 minutes at 4:15. That is way faster than the system I have on the Jeep and I run those tires at 30 psi because of their size and the weight of the Jeep. I would recommend this mod to anyone considering going off road.