2025 4Runner Gen 6 Suspension: SDM vs KDSS — What Changed and What You Need After a Lift
If you just bought a 2025 4Runner and you're researching KDSS, here's the first thing you need to know: the Gen 6 4Runner doesn't have KDSS.
DrKDSS has been working with the Gen 6 platform since launch, validating fitment and documenting exactly how the suspension geometry changes after a lift. What follows is based on that firsthand work — not spec sheets.
Toyota replaced KDSS on the Gen 6 4Runner with a different system called SDM — Stabilizer with Disconnection Mechanism. It's not a hydraulic system. It's not automatic. And it works completely differently from the KDSS you may have read about on Gen 5 4Runners.
This guide explains what SDM actually is, how it compares to KDSS, which trims have it, and what suspension corrections the Gen 6 needs after a lift.
What Is SDM on the 2025 4Runner?
SDM stands for Stabilizer with Disconnection Mechanism. It's an electronically controlled sway bar disconnect system — similar in concept to what Jeep has offered on the Wrangler for years.
Here's how it works: the front stabilizer bar is split into two halves with an electronic actuator mounted directly to the bar at the front axle. When you press a button, the actuator unlocks, allowing the two halves of the bar to move independently. This increases front wheel articulation off-road by removing the lateral resistance the sway bar normally provides.
When you get back on pavement, press the button again and the bar re-engages.
That's the key difference from KDSS — SDM is manual and driver-controlled. KDSS is hydraulic and automatic, reading suspension travel and engaging or disengaging the sway bars without any input from the driver. KDSS also manages both the front and rear sway bars simultaneously. SDM only affects the front.
How Is Gen 6 SDM Different from Gen 5 KDSS?
This is the question most Gen 5 owners upgrading to a Gen 6 are asking, and the answer matters for how you approach a lift.
KDSS (Gen 5 4Runner — 2003–2024):
- Hydraulic system connecting front and rear sway bars
- Automatic — no driver input required
- Engages and disengages based on suspension travel
- Manages both front and rear sway bar articulation simultaneously
- Complex hydraulic components that require geometry correction after a lift
- Available on TRD Off-Road, Trail Edition, and optioned on TRD Pro trims
SDM (Gen 6 4Runner — 2025+):
- Electronic actuator mounted directly to the front stabilizer bar
- Manual — driver-controlled via button
- Front sway bar only — rear is not affected
- Simpler system with fewer hydraulic components
- Standard on TRD Pro and Trailhunter trims only
- Not available on TRD Off-Road or other trims
From a pure off-road articulation standpoint, SDM is actually more straightforward — when it's disconnected, the sway bar is fully disconnected. KDSS was a hydraulic compromise that worked automatically but had limitations, including stiffening at speeds above about 12 mph which made fast off-road driving rougher than a non-KDSS setup.
From a lifting standpoint, SDM is simpler to work with — there are no hydraulic actuators to stress, no hydraulic lines to account for, and no KDSS-specific geometry complications from the sway bar link side.
However, lifting a Gen 6 still creates track bar geometry problems — and that's where the correction work happens.
Which 2025 4Runner Trims Have SDM?
SDM is not available on every Gen 6 trim. Here's the breakdown:
- TRD Pro — SDM standard
- Trailhunter — SDM standard
- TRD Off-Road — no SDM
- TRD Sport — no SDM
- SR5 — no SDM
- Limited — no SDM
If you're on a TRD Off-Road or lower trim, your Gen 6 has a conventional fixed sway bar with no disconnect mechanism of any kind. Lifting this trim is actually simpler from a sway bar standpoint — there's no disconnect system to account for — but track bar correction is still necessary.
Does the Gen 6 4Runner Still Need Suspension Correction After a Lift?
Yes — for a different reason than the Gen 5.
On the Gen 5 with KDSS, a lift created two problems: sway bar link bind from the KDSS hydraulic geometry, and track bar geometry shift pulling the axle off-center.
On the Gen 6 with SDM, the sway bar link complexity is significantly reduced — there are no hydraulic actuators to stress. But the track bar geometry problem is identical. Lifting steepens the front track bar angle and pulls the front axle off-center, causing the same symptoms Gen 5 owners have dealt with for years:
- Steering pull to one side
- Steering wheel sitting off-center
- Uneven front tire wear
- A front end that doesn't feel quite right regardless of alignment
A wheel alignment addresses the symptoms temporarily but doesn't fix the root cause. The axle is off-center, and until the track bar geometry is corrected, it stays that way.
What Suspension Corrections Does the Gen 6 4Runner Need After a Lift?
Track bar correction — confirmed fitment
The DrKDSS B.O.T.C.K. (Bolt-On Track Bar Correction Kit) fits the Gen 6 4Runner and corrects front track bar geometry after a lift. It relocates the track bar mounting point to restore proper axle centering at the new ride height. Fully bolt-on, no welding, no fabrication.
Available in two versions:
- Standard — for vertical lifts
- Shorty — for builds that push the wheels and suspension outward
Sway bar links — platform specific
Because the Gen 6 uses SDM rather than KDSS, the sway bar link situation is different from the Gen 5. If you're running a TRD Pro or Trailhunter with SDM, or a fixed sway bar trim without any disconnect, confirm fitment with DrKDSS before purchasing sway bar link upgrades — the Gen 6 platform is newer and fitment specifics are still being validated for some configurations.
What About KDSS on the Gen 6? Is It Gone for Good?
On the 4Runner, yes — KDSS has been discontinued in favor of SDM. Toyota has moved KDSS to Lexus-exclusive territory, where it continues on the GX550 as e-KDSS (electronic KDSS), an evolved version of the hydraulic system.
If you specifically want a KDSS-equipped Toyota platform, your current options are the Lexus GX460 (2010–2023), Lexus GX470 (2003–2009), Lexus GX550 (2024+), and Gen 5 4Runner (2003–2024) used market.
Frequently Asked Questions
Does the 2025 4Runner have KDSS? No. The Gen 6 4Runner replaced KDSS with SDM — Stabilizer with Disconnection Mechanism. It's an electronic front sway bar disconnect, not a hydraulic system. KDSS is now exclusive to Lexus vehicles.
What is SDM on the Gen 6 4Runner? SDM is an electronically controlled front sway bar disconnect. Press a button and the front stabilizer bar splits, allowing the two halves to move independently for increased wheel articulation off-road. It's standard on TRD Pro and Trailhunter trims only.
Do I still need track bar correction if I lift a Gen 6 4Runner? Yes. Regardless of whether your Gen 6 has SDM or a fixed sway bar, lifting steepens the front track bar angle and pulls the axle off-center. The DrKDSS B.O.T.C.K. corrects this on the Gen 6 platform with a fully bolt-on install.
Is SDM better or worse than KDSS for off-road use? Different, not necessarily worse. SDM fully disconnects the front sway bar when engaged, which can mean more articulation than KDSS in some situations. KDSS is automatic and manages both front and rear bars simultaneously. SDM is manual and front-only. For most trail use, SDM is effective — the tradeoff is that you have to remember to engage and disengage it manually.
Which Gen 6 4Runner trims have SDM? TRD Pro and Trailhunter only. TRD Off-Road, TRD Sport, SR5, and Limited do not have SDM and use a conventional fixed sway bar.
Can I add SDM to a Gen 6 trim that didn't come with it? Not as a simple aftermarket addition — SDM requires specific hardware integrated into the front stabilizer bar. If SDM is a priority, it needs to be on the trim you purchase.
What DrKDSS parts fit the Gen 6 4Runner? The B.O.T.C.K. track bar correction kit is confirmed for Gen 6 fitment. For sway bar link questions specific to your trim and lift height, contact DrKDSS directly for the most current fitment information as the platform continues to be validated.