Blackgate Customs, KDSS Rear Sway Bar Drop Kit (Spacers) Step-By-Step Install For the 5th Gen 4Runner
Today we’re excited to introduce a relatively new product for KDSS equipped 4Runners! This simple yet well-thought-out product solves a common problem with KDSS 4Runners and helps your extended travel suspension perform to its fullest capacity at full droop!
Before diving in, let’s take a look at both the history and function of Toyota’s KDSS system.
Brief History of KDSS
In the early 2000s, Toyota set its sights on improving the on-road performance of its SUVs with a suspension assistance system. Before KDSS was in production, Toyota introduced X-REAS (X-Relative Absorber System).
X-REAS debuted on the 4th Gen 4runner (2002-2009) way back in 2002. The system links dampers diagonally with hydraulic hoses/fluid using a mechanical center valve. Its primary purpose is to reduce body roll during hard cornering. X-REAS was standard in the 4th Gen Sport Edition and it was optional in the SR5 and Limited trims.
A short two years later Toyota debuted KDSS. Slightly different from X-REAS, the Kinetic Dynamic Suspension System (KDSS) was first implemented in 2004 in the Lexus GX 470 and was eventually adopted into the 5th Gen 4Runner Trail Editions in Fall 2009. In 2017, Toyota renamed the Trail Edition trim to TRD Offroad, but the KDSS system was still included in 2017+ TRD 4Runners.
Outside of the 5th Gen 4Runner, KDSS is also still used in the 2008-present Toyota Land Cruisers, 2004-present Lexus GXs, and 2010-present Toyota Prados…and a wild card, KDSS is also used in some McLaren supercars past and present.
KDSS, PROs vs CONs
- Better cornering on-road
- Less Body Roll
- Sway-bar disengage off-road when KDSS goes “limp”
- Overall improved ride
- Compatible with Standard and Extended Travel Suspension
- Incompatible with true Long-Travel suspensions
- Long term Maintenance and/or Failure
- Limited options KDSS compatible armor/suspension/accessories
- The added price tag for the option
- Costly to Delete the System
- Suggested max 1” lift in Rear
- Suggested max 2.5” lift in Front
How Does KDSS Work?
KDSS is fully mechanical and the system really only engages when hydraulic pressures become unequal. The pressures can become unequal in two ways… in-phase and opposite phases. KDSS works in real-time by reacting to both in-phase and opposite phase compression/tension and making proper adjustments using the hydraulic rams.
KDSS basically works by attaching hydraulic rams to a floating sway bar that is already a beefier/stiffer sway bar than a normal sway bar. Since the sway bar floats and can become disengaged, it’s possible to use a beefier/stiffer sway bar, to begin with. As a result, KDSS provides better control of body roll on-road and the system also goes limp and effectively disengages the sway bars during off-road conditions. Best of both worlds!
On-road, most circumstances such as cornering and hard cornering will create in-phase compression/tension. In this situation, KDSS engages and provides resistances at the sway bar so body roll is reduced.
Off-road, KDSS is designed to improve wheel articulation. When encountering obstacles that demand extended travel such as moguls, washouts, boulders, and other uneven terrain, opposite compression/tension created from both front-to-rear and driver-to-passenger. During these conditions, the hydraulics respond by going limp. Once the hydraulic rams go limp, the result is effective disengagement of the sway-bar which improves wheel articulation for your standard or extended travel suspension.
The Problem with KDSS…
One notable problem with lifted KDSS 4Runners is that your rear sway bar KDSS links will likely make contact with the rear track bar AFTER extended travel shocks and taller springs are installed. This result is a binding of suspension (due to the contact) and prevention of full-droop form occurring when needed.
This has been touched on throughout multiple places on Trail 4Runner. To start, Brenan wrote a post on the Icon track bar that didn’t work out too well. Icon claimed that this track bar was supposed to “fix” the problem but as Brenan started, it clearly did not. I believe Brenan ended up going with the Sonoran Steel track bar which costs around $400+ to completely solve the issue but we have not seen a post on that yet.
Testing for Rear Sway Bar Contact
This problem may or may not occur on your KDSS equipped 4Runner and depends on the specs of lift/suspension you have installed. Chances are if you have installed an extended travel suspension, the contact and binding are likely occurring. If you are unsure if this problem is occurring, you can inspect the track bar for contact abrasion marks in the area where the sway bar and links would contact it.
If you have not taken your 4Runner into full droop naturally you may not have any contact abrasion marks BUT you can perform a simple test to see if you have the problem.
Jack up your vehicle from the tow hitch area (not the differential) just high enough to simulate full droop. Once tires are off the ground, examine the KDSS links to see if they’re contacting the track bar. Chances are if you have extended travel lift, there will be contact. This contact binds the suspension and prevents your extended travel components from fully extending.
Today I’m happy to introduce a solution to this problem by way of a new product from Blackgate Customs that eliminates this contact between the sway bar KDSS links and the track bar. It is the KDSS Rear Sway Bar Drop Kit by Black Gate Customs.
The KDSS Rear Sway Bar Drop Kit is a pair of high quality 6061 Billet Aluminum spacers that are engineered to create the clearance needed when your lifted 4Runner is approaching full droop!
After installation of the spacers, your rear KDSS sway bar links will clear the rear track bar resulting in the clearance needed between track bar and sway bar links for full droop.
Let’s get to the installation!
Tools & Materials
- Updated Product: Visit Dr. KDSS
- 14mm Socket
- 19mm Socket
- 19mm Open Wrench
- Torque Wrench
- Jack & Jack Stands
- Anti-seize (recommended)
Step 1. Jack Up Passenger Side + Unthread Factory Bolts
Jack up the passenger side rear sway bar and unthread the factory bolts being careful not to break the bolts.
Step 2. Lower Jack To Separate Sway Bar & Link
Once both bolts are removed, lower the jack slightly to allow the sway bar to separate from the link creating space for the passenger side spacer. Apply a thin layer of anti-seize onto the top of the spacer and insert the spacer between the bushing and link.
Step 3. Reinstall Sway Bar & Close Up Any Gaps
Jack the sway bar back up to close any gaps between the bushing, spacer, and end link. Using the provided bolts (again apply a thin layer of anti-seize on the bolts) torque them down to 60ft/lb.
Step 4. Jack Up Driver’s Side & Lower Sway Bar Again
Move the jack to the driver’s side and slightly jack up the sway bar again… repeat the process of removing the end link bolts. Before installing the spacer, you need to next remove the sway bar from the axle. Using a 19mm socket and open wrench, turn the bolt head side to loosen, NOT THE NUT.
Once the driver’s side is disconnected but sway bar still supported by the jack, loosen the sway bar from the axle on the passenger side.
Step 5. Lower Jack To Install Spacer
With the sway bar now fully disconnected from the axle, lower the jack slightly to create space for the spacer to be installed on the driver’s side. Use a thin layer of anti-seize on the top of the spacer.
Step 6. Jack Up Sway Bar & Reconnect Side To Axel
Close everything up by first jacking back up the sway bar (we’re still on the driver’s side) and reconnect the passenger side sway bar back to the axle. Apply anti-seize and torque down to 80ft/lb.
Next, continue jacking the sway bar up more and bolt up the driver’s side sway bar, spacer, and end link using the provided bolts. Use anti-seize and torque down to 60ft/lb.
Step 7. Lower Jack & Reposition It Over Driver’s Side Sway Bar + Axle
Once the driver’s side end link and spacer are buttoned up, lower the jack and reposition it over to the support where the driver’s side sway bar connects to the axle. Raise the jack up to assist in reconnecting the sway bar to the axle. Use anti-seize once more and torque it down to 80ft/lb making sure the bolt head is on the inside.
Step 8. Ensure Sway Bar Links Are Positioned Correctly (Optional)
Once the install is complete, you can use your jack at the tow hitch area and jack up your truck to full droop with both wheels off the ground and observe that your sway bar links are no longer contacting the track bar in full droop position! Success!
Simple but totally effective!
Spacers created the clearance needed and there’s no more binding up in the suspension in the rear when approaching full droop. Install was easy, took about 45 minutes and the instructions were thorough and simple to follow. We definitely recommend this option if you are experiencing contact and binding between the track bar and KDSS links.
No contact with the track bar!
Pictured above is both passenger and driver’s side at full droop illustrating the KDSS links are no longer contacting the track bar!