(KDSS) Kinetic Dynamic Suspension System?

[joseoyola8]

Hey is Jose
so im planning on getting a 2021 4Runner Offroad Premium and most of then on Southern california are already equipped with the KDSS suspension and my question its really worth it? 1750 USD extra for the KDSS.

Thanks for any help or comment will be highly appreciated

 

[Billiebob]

Technical advantage maybe but one more thing to fail.
Mostly marketing to sell a system you have no control over.
60 years of driving, I've done disconnects but for the few times I did anything extreme even manual disconnects were not worth the rffort.

Disconnects likely improve traction in 4WD when articulating but honestly even with sway bars disconnected you can easily over articulate and lose traction in 4WD.
For $1750. Selectable Lockers front and rear will work better to maintain traction.

 

[LostInThought]

Take this as "FWIW" with a grain of salt.

When I was shopping for my current vehicle (2018 4Runner TRD-OffRoad), I did a test drive of two 4runners, one with and one without KDSS, about 60 minutes apart on rough trail, soft sand, and arroyo embankments southwest of Santa Fe. (To this day, I still wonder if the sales manager knows that this salesman was allowing people to test their inventory in this way!)

I actually got to test KDSS, A-Trac, Rear-Locker, and Crawl-Control off-road, on trail that pushed the vehicles (Wife did NOT enjoy that part of the test drive ). After actually testing with and without KDSS as close to side-by-side as I could, I bought the TRD-OffRoad with KDSS (all four features actually) - I felt convinced that the equipped vehicle was more capable. (Dual factory lockers were not an available option at the time of purchase.)

Now, after having driven the vehicle with KDSS/Locker/A-Trac/Crawl-Control for about three and a half years, my feeling is that I drive this vehicle differently with these features, versus a vehicle without them (like my old Chevy). A-Trac + rear locker is different from dual lockers - you adapt your driving to the vehicle you're in. For instance, dual lockers necessarily lose some traction in a tighter turn (at least two tires MUST slip in the turn), whereas rear locker + A-Trac maintains traction up-front, only slipping one of the rear wheels - you adapt your driving to the difference. Likewise, while KDSS has all the stability of a sway-bar suspension on pavement, on rougher off-pavement "roads" (yeah, that label can be questionable around here), KDSS falls somewhere between sway-bar and no-sway-bar and you drive it like a KDSS suspension, not like a sway-bar suspension or a no-sway-bar suspension. Again, you adapt your driving to the vehicle.

I haven't felt a need to add a front locker so far - for my usage (mostly forest roads in the Jemez, Sangre de Christo, and San Juan Mountains of the Southern Rockies of Northern New Mexico and some desert off-road in Southern New Mexico), I haven't run into an obstacle that the current configuration couldn't deal with, but YMMV - BUT I don't intentionally seek out crazy trails.

If I were to do it all over, I'd still buy the KDSS-equipped vehicle. Just my opinion, I could be wrong.

(with all that said, a set of cheap traction boards are still good insurance)

 

[LostInThought]

Take this as "FWIW" with a grain of salt.

When I was shopping for my current vehicle (2018 4Runner TRD-OffRoad), I did a test drive of two 4runners, one with and one without KDSS, about 60 minutes apart on rough trail, soft sand, and arroyo embankments southwest of Santa Fe. (To this day, I still wonder if the sales manager knows that this salesman was allowing people to test their inventory in this way!)

I actually got to test KDSS, A-Trac, Rear-Locker, and Crawl-Control off-road, on trail that pushed the vehicles (Wife did NOT enjoy that part of the test drive ). After actually testing with and without KDSS as close to side-by-side as I could, I bought the TRD-OffRoad with KDSS (all four features actually) - I felt convinced that the equipped vehicle was more capable. (Dual factory lockers were not an available option at the time of purchase.)

Now, after having driven the vehicle with KDSS/Locker/A-Trac/Crawl-Control for about three and a half years, my feeling is that I drive this vehicle differently with these features, versus a vehicle without them (like my old Chevy). A-Trac + rear locker is different from dual lockers - you adapt your driving to the vehicle you're in. For instance, dual lockers necessarily lose some traction in a tighter turn (at least two tires MUST slip in the turn), whereas rear locker + A-Trac maintains traction up-front, only slipping one of the rear wheels - you adapt your driving to the difference. Likewise, while KDSS has all the stability of a sway-bar suspension on pavement, on rougher off-pavement "roads" (yeah, that label can be questionable around here), KDSS falls somewhere between sway-bar and no-sway-bar and you drive it like a KDSS suspension, not like a sway-bar suspension or a no-sway-bar suspension. Again, you adapt your driving to the vehicle.

I haven't felt a need to add a front locker so far - for my usage (mostly forest roads in the Jemez, Sangre de Christo, and San Juan Mountains of the Southern Rockies of Northern New Mexico and some desert off-road in Southern New Mexico), I haven't run into an obstacle that the current configuration couldn't deal with, but YMMV - BUT I don't intentionally seek out crazy trails.

If I were to do it all over, I'd still buy the KDSS-equipped vehicle. Just my opinion, I could be wrong.

(with all that said, a set of cheap traction boards are still good insurance)

One other thing to consider: If you intend to lift the vehicle, KDSS will limit the lift to ~3inches - a lot for a vehicle that already has ~10inches of clearance stock+good tires. For more than 3inches, in addition to shocks/springs, you'll need to change UCAs and add a diff-drop in addition to mucking with the KDSS.

The approach, departure, and breakover angles are already pretty decent, but obviously these DO benefit from a suspension lift and many opt for 2-3inches for the angles improvement. Sliders and bumpers will make a difference here too. This collection of mods isn't cheap.

The tires are another matter. The front fender well shape on a 4Runner basically basically accommodates 275/70R17 tires without mods or lift (a few have claimed that some brands of 285/70R17 may not rub in the stock config), but with a lift and a small reshaping on the front fenders and a body-mount chop you can consistently accommodate 285/70R17 tires. (body mount chop: cut the end of the chassis' body mount back and weld a plate back over the open end). IMHO that's a lot of effort and an enormous cost for 10mm of tire width and another ~9mm of (tire) clearance - tire placement on the trail will make MUCH more difference. Going beyond 285's is generally a bigger deal and I'm pretty sure that 275's or 285's are the largest that will fit in the spare tire well under the vehicle - any more requires relocating the spare.

 

[KAIONE]

I bought a 2021 4Runner with the KDSS because of everything @BCNP4runner just mentioned above and would buy it again for the same reasons. The local parts guy, who I trust, told me I’d end up removing it in the end anyway, has now pointed out that there are 3” lift kits built specifically to deal with the KDSS system, I believe it to be a non-issue. With 265’s and no lift I can use 95% of forest roads in the PNW. Was just in a foot of snow, no problem, loved every minute of it. My $.02

 

[LostInThought]

I bought a 2021 4Runner with the KDSS because of everything @BCNP4runner just mentioned above and would buy it again for the same reasons. The local parts guy, who I trust, told me I’d end up removing it in the end anyway, has now pointed out that there are 3” lift kits built specifically to deal with the KDSS system, I believe it to be a non-issue. With 285’s and no lift I can use 95% of forest roads in the PNW. Was just in a foot of snow, no problem, loved every minute of it. My $.02

Which 285's are you running without lift? Did you have to do any mods to the fender well or do the BMC?

 

[Old Tanker]

...with a lift and a small reshaping on the front fenders and a body-mount chop you can consistently accommodate 285/70R17 tires. (body mount chop: cut the end of the chassis' body mount back and weld a plate back over the open end). IMHO that's a lot of effort and an enormous cost for 10mm of tire width and another ~9mm of (tire) clearance ...

I wouldn't call it an enormous cost - I had a local welder relocate both body mounts - a larger job than just a chop - and install a panhard correction kit for under $600. Removing the front mud guards and flattening the pinch welds is a DIY job. I agree that it is a lot of effort just to get another half inch of tire clearance.

 

[ZombieCat]

I have a 2016 Trail; it has A-trac and Crawl Control, but NO KDSS. Added a 3” Toytec lift, 285 70/R17 Ridge Grapplers and RSG rock sliders. It’s reasonably capable on rough tracks, but I don’t do anything extreme. I didn’t modify the fenders or wheel wells and I’ve never had a problem with rubbing.
I’ve noticed there are more lift kits that can accommodate KDSS now that the TRDs are more popular. Research your options and calculate any added cost to lift the vehicle with KDSS. I read the 4Runner and Taco forums a lot before buying/modifying my truck.

 

[KAIONE]

I bought a 2021 4Runner with the KDSS because of everything @BCNP4runner just mentioned above and would buy it again for the same reasons. The local parts guy, who I trust, told me I’d end up removing it in the end anyway, has now pointed out that there are 3” lift kits built specifically to deal with the KDSS system, I believe it to be a non-issue. With 285’s and no lift I can use 95% of forest roads in the PNW. Was just in a foot of snow, no problem, loved every minute of it. My $.02

Which 285's are you running without lift? Did you have to do any mods to the fender well or do the BMC?

Sorry I meant 265’s, I’ll change that. Was looking at getting 285’s with no lift on another thread.

 

[KAIONE]

I bought a 2021 4Runner with the KDSS because of everything @BCNP4runner just mentioned above and would buy it again for the same reasons. The local parts guy, who I trust, told me I’d end up removing it in the end anyway, has now pointed out that there are 3” lift kits built specifically to deal with the KDSS system, I believe it to be a non-issue. With 285’s and no lift I can use 95% of forest roads in the PNW. Was just in a foot of snow, no problem, loved every minute of it. My $.02

Which 285's are you running without lift? Did you have to do any mods to the fender well or do the BMC?

I’ve been told twice now that KM3’s 285’s rub on the control arms, along with other some fender liner parts.

 

[KAIONE]

I bought a 2021 4Runner with the KDSS because of everything @BCNP4runner just mentioned above and would buy it again for the same reasons. The local parts guy, who I trust, told me I’d end up removing it in the end anyway, has now pointed out that there are 3” lift kits built specifically to deal with the KDSS system, I believe it to be a non-issue. With 285’s and no lift I can use 95% of forest roads in the PNW. Was just in a foot of snow, no problem, loved every minute of it. My $.02

Which 285's are you running without lift? Did you have to do any mods to the fender well or do the BMC?

I’m trying to find some to give them a shot. You heard of any? Lot of different opinions out there.

 

[rho]

The folks I wheel with frequently that have 4R's have all removed it or sought out trucks without it from the factory. Then again they're also running LT suspensions, or are considering stuff like Marlin Crawlers RCLT. Most of them didn't like the way it drove or some of the transitions between the system working/not working. These folks are also on 33's at the smallest and a bunch of them have moved onto 34's/35's. Ymmv based on what your needs are for the truck and what your long term goals and modification plans are.

If you end up getting a rig with it, spend some time in an OHV area or on some mellow trails to get used to the behavior of it, especially if you've got a background in off-road driving already. I drove a friends (stockish) truck with it and I felt it negatively impacted control in off-camber situations, but thats my impression coming from a jeep with with a lot of wheel travel and articulation, so take it with a grain of salt.

 

[Old Tanker]

You can install a switch to turn KDSS on and off. Somewhat like a sway bar disconnect.

 

[samba]

You can install a switch to turn KDSS on and off. Somewhat like a sway bar disconnect.

How has your experience been with the switch.

 

[Pkins44]

If it’s your daily driver and your offroad adventures are less rock crawling and more overlanding, I’d recommend kdss for its improvements on-road, swerving and high speed cornering. I wouldn’t say it has ever hurt my off-roading over the last five years and just elected to keep it when installing a lift recently but I sure did notice a big difference on the test drive when comparing the same models one with and one without.

I’m not an extreme off-roader but with only a bmc and 285x3s it has never failed me from the Rockies to the swamps of Florida 140k miles and counting.

It is an expensive system to work on I have heard but I have not had any issues and the “deactivating” process is simple when working on the suspension yourself.

 

[Advtres]

I have a 2016 Trail; it has A-trac and Crawl Control, but NO KDSS. Added a 3” Toytec lift, 285 70/R17 Ridge Grapplers and RSG rock sliders. It’s reasonably capable on rough tracks, but I don’t do anything extreme. I didn’t modify the fenders or wheel wells and I’ve never had a problem with rubbing.
I’ve noticed there are more lift kits that can accommodate KDSS now that the TRDs are more popular. Research your options and calculate any added cost to lift the vehicle with KDSS. I read the 4Runner and Taco forums a lot before buying/modifying my truck.

Good to know on the 285s, I have the the trail grappler tire in 265 and when they run down I think I can go with the 285s ( I have the toytec Lift as well)

 

[Old Tanker]

How has your experience been with the switch.

I installed the harness and connected its relay to one of my Switchpro outputs. Install was very easy (hardest part was routing a wire through the firewall to the Switchpro module under the hood). All I have to do is press a button and it turns the KDSS off (dash KDSS light comes on, KDSS disengages into soft mode that is normally limited to 12 mph). Nothing dramatic, but handy when running an offroad trail at 13-20 mph.

 

[Cpol]

Dr kdss if your going to lift