Looking for more off-road capability from our 5th Gen Toyota 4Runner, we went with the ToyTec BOSS 2.0 suspension package.

Toyota followers are passionate about the trucks they drive, and for good reason. From the earliest mini trucks, the 1979 4×4 pickup to its predecessor, the venerable Land Cruiser, Toyotas are unsurpassed for reliability and designs that stay true to no-nonsense off-road capability. That tradition continues with the Big 3 from Toyota: the Tacoma, Tundra and 4Runner. Combined, the trio reached a record high of 440,000 sales in 2017.

These 21st Century Toyota trucks feature many on- and off-road performance features that help eclipse previous generations. From traction control to cornering stability, they represent a blend of functionality, durability and comfort. Despite those successes, modern Toyota 4x4s have as many compromises as their predecessors. Our family began living with those modern compromises in 2014, when we chose to buy our first-ever new-from-the-dealer vehicle, a Toyota 4Runner Trail Edition.

Like 76,905 other buyers, we proudly took ownership of this tough, ladder frame SUV, which was now in its 5th generation. For all the factory spec’d traction options, the Trail Edition 4Runner leaves a lot to be desired when driving off pavement. Not a year after our purchase, Toyota unveiled its “solution” to this performance gap, rolling out the TRD Pro version of the 4Runner. Sporting Bilstein shocks, tuned coil springs and, as a result, a 2” lift (along with purely cosmetic changes), the new top-end 4Runner had finally realized a performance level to match its heritage.

ToyTec Displays
Doug Gosh began his Toyota lift business with simple spacers (L) in 2005, and has grown the business to provide a full spectrum of suspensions, from his ToyTec line to products from a range of competitors.

Buyers seeking full trail performance could, beginning in 2015, order from the factory this readymade package. And for the rest of us? Many owners wanting that level of capability had already pulled the trigger on a Trail Edition, SR5 or Limited model, and more would do so in years to come. In response, the exploding Toyota 4Runner 5th Gen aftermarket soon began to answer this call.

ToyTec and the Toyota Aftermarket

Improving the 4Runner’s suspension is relatively simple, as one learns when examining what Toyota added with the TRD Pro. Bolt on solutions mean a driveway mechanic can DIY his/her way to real performance gains. Enter ToyTec.

The roots of ToyTec started with founder Doug Gosh, whose journey began as a Toyota mechanic. Facing a big gap in available early gen lift options, Doug’s humble lift designs were simple machined spacers. From that 2005 first solution for the earliest Tacoma evolved the breadth of lift and off-road equipment ToyTec offers today. Located in Denver, the company has grown to be one of the most recognized names in Toyota circles, trail testing its suspensions throughout the Rockies

ToyTec is by no means committed solely to its own products. A dealer for countless other brands, the company’s website and the Denver headquarters’ showroom are a testament to selling whatever the customer wants. Nothing says confidence like selling a “competitor’s” best.

ToyTec BOSS kit
ToyTec’s BOSS 2.0, shown here with remote reservoir rear shocks, is hard to miss on the shelf or in the wheel well.

When I first reached out to ToyTec, the challenge posed to them was simple: which suspension fixes OEM off-road performance gaps, retains (or improves) its daily driver behavior, and doesn’t open a Pandora’s box of mechanical (or spousal) problems? David Mietzner answered the challenge (as well as my frequent phone calls and emails), and so began the journey of upgrading a spouse’s pristine, daily driver 4Runner into a Trail Edition+.

It’s not unheard of for modern Toyota 4Runner owners to build their already capable rigs into expensive, over-equipped testaments to 21st century Internet four-wheeling. Sadly, the factory spec’d capabilities of the Trail Edition are probably underestimated by many owners of this, the most capable out-of-the-box 4Runner ever. As a result, our request to ToyTec was change the suspension so that it realizes those capabilities.

Like most owners, our hope was to upsize tires, gaining another 2-3” of diameter. Having run a 275/70r17 KO2 unlifted, our goal was a 285/70r17. Starting with coil spring and spacer options, ToyTec offers numerous products to simply gain height. And, at the other end of the quality spectrum, no lack of highly dialed and race-inspired suspensions. While those Icon, King and OME solutions are capable of bombing desert washes, neither they nor the simplistic coil options struck the right balance. Dave pointed to a different complete solution designed by ToyTec for just that goal: a middle-of-the-trail solution for 80% of the trail demands, and 100% of pavement usage.

The variable height options of ToyTec BOSS suspension packages, enabled by the 2.0 coilovers’ adjustability, are fully assembled and intended for a blend of trail and street driving. A notch down from the larger 2.5” BOSS model, both use the same 650lb lipstick red coils. Both allow height adjustment from 1-3”, though only the BOSS 2.5 is rebuildable, and its shaft is a 7/8” nitro steel shock shaft compared to the 5/8” nitro steel shaft at the heart of the 2.0.

Toyota 4Runner Before After
The before/after effects of the Toytec/Total Chaos lift is noticeable without being overblown. Comparable in height to the TRD Pro’s lift, but of a higher quality, this suspension is an affordable option for surpassing the flagship 4Runner.

ToyTec allows countless options for dialing in one’s suspension, including in the BOSS kits.  The rear of the systems has its own options. Superflex Coils provide the core, with an option for HD units to handle ~200lb of added constant load (such as a rear swing-away bumper, etc). Its shock options are even more diverse, and we opted, at Dave’s suggestion, for the remote reservoir 2.0 model, an added margin of performance in response to our habit of towing an overland trailer in the backcountry.

Because ruining the better part of what Toyota engineered in these suspensions is no one’s goal, ToyTec provides a complete set of sway bar and differential drop brackets with the BOSS kits. With Toyota’s remarkably efficient KDSS system, it’s especially important to not screw up your 4Runner or FJ Cruiser’s suspension system. In response, ToyTec has buyers indicate whether their vehicle has the dynamic sway system, with kits specific to your platform.

Completing the BOSS

The ToyTec BOSS 2.0 is complete and ready to go as packaged. But that doesn’t mean it can’t be paired with other products to more fully optimize its performance. While the solid axle rear configuration of the 4Runner is relatively simple, its front IFS has many more moving parts and complex geometry. Most importantly, the factory upper control arms (UCA’s) impose a limit on lift height if suspension alignment is to be maintained.

UCA stock comparison
Toyota’s stamped steel upper control arms are pale in comparison to the hand-made, welded and powder/clear coated Total Chaos UCA’s.

The height potential of the ToyTec BOSS lift (2.5-3”) can be attained on its own, yet it is best realized with the geometry correction that comes from replacing the upper control arms (UCAs). While work-arounds exist for retaining the stamped steel factory arms, a quality suspension should be done correctly from the outset. Like most owners, we wanted optimum handling, tire wear and ease of alignment. Castor correction can best meet factory specs with the addition of aftermarket solutions, and up to an inch of added travel can be gained.

Shop For Total Chaos Upper Control Arms

A handful of companies offer UCAs, but perhaps none is as well respected as SoCal’s Total Chaos Fabrication.  Top tier Total Chaos products have been produced for a quarter century. Tested in high speed desert travel since 1998, their suspensions include long travel designs, as well as new lower control arms, for Toyota and many other leading 4×4 platforms.

Nicole “Chaos” Pitell, accomplished desert racer, Director of Operations, and co-founder of the company, helped us with her extensive first-hand expertise as we discussed this project at Overland Expo West in 2018. Building race-ready products, all hardware from Total Chaos Fabrication is handmade in the States. The meticulously welded tubular 4130 chromoly arms are available with either heim joints (adjustable) or urethane bushing (fixed) pivots in UCA models for the 4Runner. Nicole advised that for all but the most extreme uses the latter design is more than tough enough, offers considerable cost savings, and is still far superior to the factory arms.

UCA comparison
Total Chaos Fabrication offers two options in upper control arms: urethane pivot (L) and heim joint pivot (R).

A bolt-up installation, Total Chaos UCA’s pair easily with the BOSS 2.0 and other kits offered by ToyTec. Their design offers owner-serviceable pivots. The urethane bushings have grease zircs (more on this later), while the main ball joint features a 1” stainless steel uniball seated within a PTFE cup lining. Combined with the BOSS coils, the Total Chaos UCA’s permit an inch of additional overall suspension travel.

To match the rest of the ToyTec components, we added two other key system components.  First, the OEM bump stops were swapped out for the Timbren Active Offroad Bumpstops for both the front and rear. Using their Aeon rubber, the bump stops are designed to create a graduated slowing of suspension travel as it approaches maximum compression.  In theory, these Timbren units act to cushion and ease big hits on the trail. For the kind of true “Trail Edition” conditions our Toyota 4Runner traverses, that added protection gets used.

Shop for Timbren Active Bump Stops

Lift Installation

Traveling from Utah to Denver to tour ToyTec and have the BOSS 2.0 installed offered not only an in depth look at the company, but also an eight-hour drive each direction to compare results.  Additionally, it gave the opportunity to watch and discuss the kits installation in the large, modern and extremely clean ToyTec shop. Situated in the same large commercial complex, the shop is under the same roof and directly adjacent to the showroom, company offices, and impressively large warehouse.

Toyota 4Runner Front Suspension Installed
Finished installation of ToyTec BOSS 2.0 front with Total Chaos UCA’s, along with Timbren’s Active Offroad Bumpstops (center).

Rear installed
Finished installation of the BOSS 2.0 rear, along with Timbren’s Active Offroad Bumpstops. [Note: remote reservoir hoses shown here required additional securing to the frame to prevent contact with tire.]
Installation with an experienced technician has many advantages, and with Toyota’s KDSS-equipped 4Runner, a suspension upgrade makes that especially true. Although a three-banana home installation, the six-hour process that ToyTec’s lead installer single-handedly completed is going to take a good deal longer for those wishing to DIY. Watching the steps first-hand was helpful to appreciate the tricks, the sequencing and the means for properly treating the 4Runner’s Kinetic Dynamic Suspension System.

To properly align the freshly installed BOSS 2.0 and Total Chaos UCA’s, ToyTec has invested in Hunter Engineering’s latest Hawkeye Elite FIA system. Precision alignments are essential in outfitting a 4×4’s suspension upgrade, and leave no room for guesswork or outdated equipment. The efficacy of the alignment has been seen in the 25,000 miles we’ve put on the lift over 20 months. Tire wear has been excellent. No adjustments, realignments or component tightening have been required.

Toyota 4Runner Suspension Alignment
ToyTec’s installations include a precision alignment on Hunter’s best. With ToyTec’s taller lifts, such as on the shop’s 4Runner, precision components are increasingly important.

Behind the Wheel

Pulling out from the shop I was struck by how tight the steering felt. Why did it feel like it was firmer, less darty? The straight-line tracking was clearly enhanced. It was not so much that it was loose before, but it was lighter before. Now it felt more stable.

With hundreds of miles of interstate on the drive westward, the feeling was a bit different. Still firm, but a hint of seeking to run true and straight. Was this my tiredness? I noticed it more at night on the drive to WY. These telltale, seat-of-the-pants impressions were the first of many to come as I got to know the manners and mannerisms of the ToyTec/Total Chaos combo.

Impacting seams on the road, potholes and other surface distortions, I soon found, had become clearly more muted. The impacts were dulled, and I found myself not dreading bumps. That said, they did not disappear. Nor did they feel like I was in a marshmallow suspension that fully soaked them up. The feel of the 4Runner when lightly loaded (which I was) stayed generally true. That is, the reminder that it is a truck designed to handle loads, and whose suspension softens and rides best with 700lb+, was still present. However, the harsh stock ride we had always endured was no longer nagging.

ToyTec BOSS Suspension Wheeling 2

Cornering was an aspect of the lift I was very interested in observing. The joy and safety of the KDSS system was a Toyota marvel I knew needed to be retained. Thus, I was acutely sensitive to how the BOSS impacted it. With some gusto (and worry) I took on ramps, corners and subsequent interstate, mountain hairpins and canyon curves without backing off on speed. Over those initial hours of aggressive driving in mixed conditions it was clear that the KDSS system was intact. However, there is no overcoming the centrifugal forces placed on the driver as lift height increases. In the most spirited turns, a modest increase in driver lean can be felt. On the other hand, the 4Runner itself felt as flat as ever. Steering itself felt more sensitive to unsettling if impacting road surface distortions. This was not at a concerning level, but an attuned driver would not fail to notice the change.

These characteristics seemed to be, in part, related to the narrow factory stance, which grows more accentuated with lifting. It was purposeful that our new SpiderTrax wheel spacers were not installed initially. However, the need for a widened stance for performance and safety and not merely appearances was underscored in the initial days of driving.

Not surprisingly, the 2-3” of lift from the BOSS increases lean in hard cornering and spirited canyon twisties. While not excessive, those accustomed to the excellent KDSS manners will long for that lost stability. Enter the SpiderTrax spacers. We ran the ToyTec alone for several months to become familiar with its habits. When the big blue Spidertrax spacers (another Colorado company) finally were installed the change was immediately clear. By only increasing the stance by the height the suspension was lifted (2.5”), the spacers regained near factory levels of flatness in curves and hard cornering.

SpiderTrax Spacers
SpiderTrax 1.25” spacers widen the 4Runner’s stance, improving stability and handling.

For only a couple hundred dollars, the SpiderTrax spacers, made in the U.S. with 6061T6 anodized aluminum, are a no-brainer for the BOSS and similar lifts on the 4Runner. The installation is straightforward, though a torque wrench is required to assure the specs are accurately followed for both the wheel and spacer nuts. High strength Loctite is provided, with retorquing following an initial break-in period also required for safety.

Be forewarned that wheel spacers alter the arc of front tires as they turn, and can increase interference with wheel wells. Such was the case with the Bridgestone Dueller AT Revo 3’s we mounted on stock rims. Sized at 285/70r17, the added diameter along with the SpiderTrax meant some contact points needed to be addressed.

Shop For SpiderTrax Wheel Spacers

With the stance corrected, the true character of the highway manners emerge for the ToyTec BOSS/Total Chaos suspension. There is no hiding that you are in an elevated platform. Both views and subtle centrifugal changes are felt. Although the changes are not really apparent below 40-45mph, hints of lean and how forces push you in the seat’s side bolsters appear at highway speeds. At higher speeds those same sensations become more clear, though not concerning or nervous feeling. But what about the terrain the suspension is meant to tame?

In the Dirt

The dirt track that takes you to Wyoming’s Big Sandy trailhead, portal to the Patagonia-like “Cirque of the Towers,” is a classic ribbon of washboards, ruts, gravel and dry washes, all undulating through an expanse of sagebrush and death wish darting jackrabbits. From 20-50 mph, the road revealed what we’ve now grown use to; the ToyTec BOSS 2.0 suspension soaks up the chatter and vibration that Toyota engineers didn’t. Not just a little, but significantly so. The 4Runner feels planted, no longer chattering across the endless ripples on hard-packed surface.

ToyTec BOSS Suspension Wheeling 3

When the BOSS 2.0 encounters dips and drops on real trails, it comes into its own. The ToyTec coils were created for these uneven surfaces and out-of-nowhere ruts/holes/washes. The suspension’s capacity to absorb such hits takes some getting used to; instead of instinctive braking you learn to let the components do their job.

Driving the ToyTec-equipped Trail Edition also reveals how much the system has been carefully engineered for load ranges. Whether your truck achieves those front/rear weights from fixed components (e.g., winch and bumper) or temporary loads (e.g., a week of food and trip gear), ToyTec tunes each lift configuration to match your needs. This is a distinct advantage. In our case, usage and future plans meant only a modest front bumper was likely, but the rear-end would routinely need to handle dynamic trailer tongue weights, along with other equipment.

To ToyTec’s credit, the 4Runner now comes into its own when fully loaded and ready for a week of exploring. It truly wants to be loaded up, and rewards occupants with the smooth, strong ride that results. Our BOSS kit pairs ToyTec’s remote reservoir rear shocks effectively with the heavier loads on the back of the SUV. Timbren’s Active Offroad Bumpstops add the extra safeguard when the really big “whoops” impacts threaten to overwhelm the red coils. This is the peace of mind that Toyota infers the Trail Edition will provide, but which needs aftermarket upgrades to achieve.

Our Intermountain West and Desert Southwest driving isn’t what all Toyota enthusiasts face, but it is a reliable crucible for component testing. A mélange of long, high speed interstate treks, fast curvaceous canyon highways, arrow-straight miles of washboards (think Pony Express Trail), sand washes, and banked UTV trails interspersed with rubber-streaked slickrock. Typically travelled with a 2,000lb trailer in tow, these varied terrains are helpful for seeing how any suspension or tire bears up.

ToyTec BOSS Suspension Wheeling 4
After leveling the 4Runner’s suspension, some minor rear-end sag was predictable once gear and a trailer was added.

The other significant improvement that hits you about the BOSS setup is the virtual end of nosedive under braking. Even during serious panic stops. This disconcerting feeling – the truck’s rear rising up as the front squats heavily, which all 5th Gen owners know well – becomes a thing of the past with ToyTec’s front coilovers. For both safety and comfort this is a tremendous plus, and illustrates the combined value of both the 650lb rated front coils and the 200psi gas charge in the paired struts. This improvement is more evidence that Toyota engineers’ work – which is known to favor a slight “stinkbug” suspension to permit heavy rear loads – can be improved upon. And it’s an improvement that matters both on pavement and off, as stopping becomes safer in all settings.


No one wants to face serving a suspension. Short of shock rebuilds, a suspension ought to do its thing and not cry out for TLC. While ToyTec’s BOSS 2.0 requires no maintenance [Note: only its 2.5 shocks can be rebuilt], the same is not true of the UCA’s from Total Chaos. Designed for minimum care, the arms nonetheless can’t be ignored.

Two essential lubrication points need to be routinely addressed with the UCA’s pivots. First, the main Uniball joint should be regularly lubricated with a dry PTFE or Tri-Flow. This takes mere seconds, and helps alleviate friction, though it does nothing for the catchment basin the cup offers for grit and grime to build up.

More involved is greasing of the main pivot for the UCAs. Total Chaos provides excellent video instructions for this maintenance process. The most crucial step is loosening the main pivot’s through bolt to prevent the injected grease from deforming, and thereby permanently damaging, the urethane bushings. While Total Chaos sells replacement parts, preventing damaged parts is simple by following the described steps.

Do the arms remain silent? In our experience, they do for a time. Nonetheless, squeaks reemerge as the suspension cycles through any road surface changes. While not an overbearing sound with windows up, when they’re down it’s not tenable. Total Chaos says owners need not remove wheels to grease the through bolt, but I can’t recommend that. Tension on the brake line alone requires loosening a clamp to allow wrench movement. As a result, the process turns out to be a 30-minute process…if you’re fast.

ToyTec BOSS Suspension Closing

To pair the ToyTec BOSS 2.0/Total Chaos lift with a proper tire may mean attention of a different kind. Toyota’s factory mud flaps for the front wheel wells are known contact points when mounting standard +size tires. The 275/70R17 Bridgestone Dueller A/T Revo 3 had just enough contact that we chose to correct it by removing the mud flaps. The SpiderTrax spacers were part of the issue, as they increase the arc of tires.

Our Final Verdict

The popular 5th Gen Toyota 4Runner remains the rare blend of SUV: affordable, comfortable, and capable off-road right off the showroom floor. But its suspension is lacking. For owners who didn’t spend the extra $4000 (or more) for the TRD Pro, ToyTec offers a range of options to dial in the suspension for the way you travel. Coupled with products from companies like Total Chaos, SpiderTrax and Timbren, your 4Runner can easily surpass any model that Toyota sells.

Thankfully, the engineering of these components also means their pavement manners retain factory handling. The best of both worlds, and for less than Mr. Toyota charges. These upgrades go a long way towards turning a 4Runner into the 4×4 that we’ve wanted.

About the Gear Doctor: Dr. Sean Michael has been designing, abusing and testing outdoor gear since the 1980’s, and began reviewing products for Off-road.com in 2000.  Today, he is Professor of Outdoor Product Design & Development at Utah State University, a product consultant, and a frequent Instructor at Overland Expo.  Follow his trips and gear abuse @thegeardoctor on Instagram.



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