What Is Toyota KDSS & Why Do You Want It?

Regarding offroading, overlanding, and tackling rugged terrain, the Toyota 4Runner has built a solid reputation for being one of the utmost reliable automotive tools. Why else would we be here, considering we don’t carry a bag of rubber ducks around for kudos. But what sets some 4Runners apart from the rest when handling tricky landscapes is the Kinetic Dynamic Suspension System, AKA “KDSS.” My intention isn’t to sway (bar) your purchase or debate suspension setups — I’ve read your comments, and a lot of you have turned a wrench far longer than me. We’re simply here to discuss the trim levels for the Toyota 4Runner that come with KDSS and what they have to offer.

Enter the Toyota TRD Off-Road (in both premium and non-premium trim levels)

In this comprehensive guide, we’re going to take a deep dive, explain what it is, and help you decide if you need it for your 4Runner. So, strap in your 4-point harness because we’re both about to embark on an educational trail to the world of suspesion.

A Virtual Keyboard Fist-Fight

I’m a chatty guy who can talk-shop on an array of topics. That said, the older I become, the more I listen, research, and consider science and less opinion.

No, I’m not talking politics; I’m saying that I’ve never built a 4 Runner from the ground up, so it’s important to understand that this article is meant to educate, not infuriate. The voyeur in me likes to watch the “experts” (tries to keep from spitting out my coffee) discuss the pros and cons of anything in the Thunderdome of the intellectual void we call forums boards. Let’s get their bloodshed addressed first, and hopefully, this will allow the remaining article to rebuild your knowledge banks to acceptable levels.

Opinion-driven: Pros

• Improved On-Road Handling: Enhances on-road stability and cornering, providing a flat and stable feel while driving. It makes the vehicle handle “better than expected” for its type.
  • (decoded: doesn’t feel top-heavy or increase sphincter factor)
• Enhanced On-Road Nimbleness: Makes the vehicle feel lighter and more nimble, improving overall agility on paved, easy/moderate offroading conditions.
  • (decoded: plays nice with asphalt too)
• Decent Off-Road Performance: _Performs “reasonably well in off-road conditions in its stock form,” providing some off-road capability without extensive modifications.
  • (decoded: I’m mad I spent more money on an aftermarket suspension because it sounded gimmicky)

Opinion-driven: Cons

• Limited Aftermarket Support: Finding aftermarket suspension, body armor, and related third-party mods can be challenging. KDSS-specific components may not be as readily available as for other suspension systems.
  • (decoded: what do you mean these rock sliders are $200 more for this trim level?)
• Complicated Maintenance: Working on it can be complex, making routine maintenance or modifications more challenging and time-consuming than simpler suspension setups.
  • (decoded: now I need to buy another Chilton’s manual)
• Incompatible with Long Travel Suspension: Incompatible with long travel suspension setups, limiting options for those seeking extensive off-road modifications.
  • (decoded: perhaps the wrong platform if you’re a Baja racer)
• Expensive Service: Servicing it can be costly, and finding qualified mechanics with experience can be difficult, “especially in certain regions.”
  • (decoded: I live off the grid and make my jerky I hunted with flat rock)
• Lift limitations: If you intend to lift your vehicle, it can limit the lift you can achieve to approximately 3 inches. This limitation is due to droop, and the design and components of the system, which may not accommodate larger lifts commonly seen with some off-road or aftermarket suspension setups.
  • (decoded: bad choice for monster trucks)

Understanding KDSS

KDSS, short for Kinetic Dynamic Suspension System, is one of the gems in Toyota’s off-road technology arsenal. At first glance, it might sound like a flux capacitor or Dr. Tohichi Hikita’s “oscillation overthruster,” a fictional device that allows an object to pass through solid matter. Okay, sorry, where was I?

At its core, KDSS is a brilliant system designed to offer the best of both worlds: off-road capability and on-road comfort. It’s offered on several of Toyota’s off-road SUV platforms including the 4Runner, Land Cruiser, and Prado, as well as Lexus’ G460 and GX470.

Let’s break down the basics. Your 4Runner’s suspension system plays a crucial role in maintaining stability and control, whether navigating tight city corners or venturing into the wilderness. Sway bars, also known as stabilizer bars or anti-roll bars, are vital to this system. They help control body roll during turns, keep your vehicle stable during sudden maneuvers, and make passengers feel like this won’t be their last ride in mortality.

PRO-TIP: Think of sway bars as the tightrope walkers of your 4Runner, ensuring it stays balanced even when the terrain gets challenging. KDSS takes this balancing act to a new level by working with the 4Runner’s onboard computer.

Hydraulic Suspension Vs. Toyota’s KDSS

It’s essential to address a common question: “What’s the difference between a hydraulic suspension system and the Toyota 4Runner’s KDSS suspension?” Both systems aim to enhance the ride quality and off-road capabilities of your vehicle, but they do so in distinct ways.

Hydraulic Suspension

These hydraulic suspensions use fluid-filled chambers and hydraulic pumps to adjust the vehicle’s ride height and damping characteristics. These systems are often associated with luxury cars, offering a smooth and comfortable ride with the ability to adjust the height of the vehicle for different driving conditions.

Often there is one hydraulic controller at each wheel as driving conditions of a luxury/sports car rarely, if ever, require a disassociation from the sway bars. Think if every time you throw your sports car into a hefty turn, you get so much automotive body roll that you feel like you’ve shaved off another year of overall life.

Toyota 4Runner KDSS Suspension

On the other hand, the Toyota 4Runner KDSS suspension, as we’ll discuss in detail, relies on a mechanical approach to connect and disconnect this rigidity with the sway bars via two hydraulic elements controlling stability to all four tires. It prioritizes this stability and traction in off-road situations, making it ideal for challenging terrains.

How Does It Work?

So, how exactly does KDSS work its magic? Picture this: You’re cruising on the highway, and your 4Runner needs to stay stable and planted. How? Hydraulics. Defined simply, hydraulic systems function using adjustable pressurized fluid, within most cases, a cylinder. Compressing the fluid creates a stiffer, more rigid function, while the reverse allows for minimized dampening or controlled movement. KDSS recognizes this and keeps the sway bars firm, minimizing body roll and maintaining on-road stability.

How It Works

Picture a sway bar: one end fixed in place and the other end equipped with a hydraulic ram, all connected by a stiff sway bar in between. This hydraulic ram plays the role of the stagecoach driver, orchestrating your vehicle’s sway and articulation.

Up Front

Up front, a robust sway bar follows the same pattern; one end is anchored firmly while the other embraces the hydraulic ram. Now, when you’re using extended travel coilovers, here’s the deal: the passenger side loses about half an inch of wheel travel in “droop” but the driver’s side remains steady, not losing an inch.

In the Rear:

The rear adopts a similar strategy, with one end fixed and the other boasting the hydraulic ram, all working to tame body roll and encourage articulation. Know that the passenger side has its limits, capable of drooping (hold on I’m getting to that, jeesh, I’m learning as I go) approximately 25 inches from the bottom of the shock mount to the center of the lower bolt. Meanwhile, the driver’s side can droop a bit more before the track bar engages with the sway bar.

In a nutshell, KDSS steps up your on-road stability game and lends a hand in off-road articulation. But like all superheroes, it has its quirks, so keep these in mind as you tailor your 4Runner to perfection.

Suspension Droop: There It Is!

“Droop” in suspension systems refers to the vertical downward movement of a vehicle’s wheels, typically when the vehicle encounters uneven terrain or obstacles. It is the opposite of “compression,” or “bump” which refers to the upward movement of the wheels. Droop is an essential aspect of suspension design, as it allows each wheel to independently follow the contours of the ground, maintaining optimal tire contact and traction. In off-road or rugged terrain situations, having adequate droop ensures that the wheels can extend downward, allowing the vehicle to navigate obstacles and uneven surfaces while keeping the tires in contact with the ground, improving stability and control.

For those of you craving extra droop on the driver’s side, aftermarket track bars are an option. But, keep in mind that they won’t completely erase the passenger side’s limitations.

You could also refer to droop as extension (opposite of compression) or rebound when talking about shocks (how quickly they return to their extended state).

Benefits

Now that we (fundamentally) understand how KDSS operates, let’s delve deeper into the benefits…

• Enhanced Offroading: Its adaptability to changing terrain is like having a seasoned off-road guide with you at all times. It ensures your 4Runner remains composed on even the roughest terrains. You’ll appreciate the improved traction and stability when the going gets tough.
• Smoothing Out the Ride: The paradox of offroading is that while you want your vehicle to handle rough terrain like a pro, you also want a smooth and comfortable ride on the highway. KDSS excels in striking this balance, making your highway journeys more pleasant and less bumpy.
• Reduced Body Roll: Body roll can be a nuisance when taking sharp turns, especially on winding mountain roads. KDSS minimizes body roll during cornering, making your 4Runner handle like a champ.
• Improved Safety: Yes! If you’ve ever felt like a vehicle is too top-heavy (see a sticker on the inside of your sun visor), you’ll know that this instability is a real factor, not to mention when you’re happily doing your best to escape humanity in the middle of nowhere. Better stability translates to improved safety, especially in emergency maneuvers. KDSS ensures that your 4Runner responds predictably to your driving commands, whether you’re swerving to avoid an obstacle or making a sudden lane change.

PRO-TIP: With KDSS, if you’re an advanced offroad driver who wants to shoot the path full-throttle, this system may be a poor choice. What it provides for stability, for the rest of us who don’t seek to be airborne before death, might feel overly controlling and even like we’re fighting against the system’s designed behavior. There are, however … ways to turn it off.

Do You Need It?

Now that we’ve covered what KDSS can do, the million-dollar question is, “do you need it?” The answer depends on your driving habits and preferences.

If you’re a hardcore off-roader who loves to tackle challenging trails regularly, it is a game-changer. It’s like having a trusted companion that ensures your 4Runner conquers the toughest terrains with ease. You’ll appreciate the improved traction and stability when the trail gets rocky, muddy, or steep. If you plan on adding a long travel suspension or you’re looking to delete sway bars in the future, then this add-on from Toyota is not for you. Some of the guys who wheel their 4Runner extremely end up deleting it. Read Brenan’s “6-year Overland 4Runner ownership” post where he goes into more detail on KDSS.

On the other hand, if your 4Runner primarily serves as a family vehicle for daily commutes and occasional road trips, you may not need KDSS. While it enhances the ride quality and off-road capabilities, the added cost might not be justified for your typical driving needs.

I own a TRD OR, and having grown up in Jeeps, Broncos, (non-KDSS) 4Runners, and other related 4×4 platforms, a KDSS setup is the most utilitarian platform for me. I live outside of Orlando and put most of my daily miles on a highway like the rest of us. But when I’m on the trail, I’ve never thought twice that I was incapable of performing most overlanding tasks… but I also don’t jump cows or attempt to recreate submarine movies with my 4Runner either, so there’s that.

Personal Test Drive

Before making a final decision, here’s a hands-on approach to consider. Of course, you can visit your local Toyota dealership and take a 4Runner equipped with KDSS and one without for a test drive. This direct comparison will allow you to feel the difference in ride quality and handling, helping you make an informed choice — but it’s not in my opinion.

A rule of thumb from Uncle Justice is also to hit a CARMAX or large pre-owned wholesale dealership. Side note… I also feel like these styles of dealerships are magnets for salespeople who have lost all desire to live and couldn’t care less if you took a test drive 90mph test drive backward over railroad tracks.

Anyways, used cars, like sneakers, won’t feel the same now as they will break in a little. Therefore, go hit a place where you can jump in and out of different trim levels, drive the same path, and see if you can get it into some dirt and hills if possible. Chances are you’re going to feel the difference with KDSS.

Mods? Well, Yeah.

If you already own a 4Runner without KDSS and find yourself yearning for its benefits, don’t despair. Some aftermarket companies offer suspension kits that can mimic the effects of KDSS to an extent. While these kits may not provide the same experience, they can enhance your offroading adventures. Any authentic offroad suspension brand that builds for Toyota [should] have KDSS options. I’ll be covering an array of specialty brands and products specific to KDSS shortly.

Just understand that if you’re contemplating lifting and doing shock packages for your trusty KDSS-equipped 4Runner, remember these limitations. You’ve got a choice: do you prefer more droop on the driver’s side, maximizing articulation, or reducing contact on the passenger side?

Final Thoughts

Look, the Toyota 4Runner KDSS suspension system is a remarkable feature that can significantly increase your offroading experience, especially if you’re newer to the lifestyle. It provides better traction, stability, and comfort when tackling challenging terrain. However, whether you need it depends on your driving habits, budget, and vehicle goal intent.

If offroading is a regular part of your life and you can comfortably afford the upgrade, KDSS is worth considering. It’s like having a seasoned off-road guide built into your 4Runner. On the other hand, if your 4Runner primarily serves as a family vehicle for daily use and will never see more than rainwater dried on it, save your money.

The decision comes down to your priorities and how you intend to use your 4Runner. Whether you opt for KDSS or stick with the standard suspension, rest assured that your 4Runner is designed to provide an excellent experience.