Rougher Ride on new TRD OR w/KDSS vs. Old one

Hi Everyone,

I just got a new 24' TRD OR with the KDSS option installed and noticed a way rougher ride compared to my 16' Trail (predecessor to TRD OR) also with KDSS when it was new. I think they come with the same Dueler H/T tires my 16' came with.

Even when bringing the tire pressure down to about 34 PSI, it still rides quite a bit rougher than the 16' did.

Did anything change in this model between the 2016 and 2024 model years? Is there anything I should check?

 

^I think both the '16 and '24 came with the lame black Tokico twin-tube shocks? Maybe the shocks on your '16 degraded over time and became softer?

34 psi is high. The owner's manual (should match door jamb sticker) page 532 shows 32 psi, and that's to pass federal handling tests fully loaded to GVWR. You can go lower to 30 psi if your vehicle is mostly empty. For reference, I still run 32 psi with load range E Duratrac RTs.

 

Sorry, I meant when my 16' Trail was new with the same Bridgestone H/T tires, it ran much smoother back then than the 24' TRD OR does now being a week old. When my 16' was new, it rode so smoothly for about the first year before everything was broken in and I guess parts started to wear.

I lowered the pressure down to 32 PSI all around, but now it rides just a little bit rougher than my 8 year old Trail that currently has Michelin A/T tires on it. Just wondering if all the relevant parts are supposed to be the same or if it might just be normal variance despite everything being the same.

 

Just a thought, but your memory of the '16 as new may not be accurate. Each time you have driven it over the past 8 years you have formed a new and updated memory of how it feels to drive, so even though you think it felt a certain way when new, it might not be accurate. They say every time we remember something, we are remembering the last time we remembered it, not the original event at all.

 

Quite a mystery. Same trucks, same OEM equipment, even the same psi, should offer very little or no noticeable difference in seat-of the-pants ride quality.

Per Sherlock, whatever remains, however improbable, is the truth. Since it’s been 8 years between, I’d wager that the real culprit here appears to be a re-calibrated butt-dial.

 

Your 2016 has been broken in for 8yrs...I'm pretty sure you would notice a difference on a brand new model...

 

Is there any chance your KDSS was inoperative on your previous 4runner? For example, if the fluid leaked out due to corrosion, maybe the hydraulic rams weren’t locking the swaybars in place. That might have made the ride very soft in comparison to a new one, since it would effectively be running without swaybars for the entire travel of the ram.

From what I understand, the swaybars equipped with KDSS are massive compared to non-kdss 4runners. Kdss should make a 4runner feel very tight compared to standard swaybars. I’ve never driven one, but I suspect it would make a regular 4runner feel like it doesn’t even have swaybars.

 

lol how do you compare a new vehicle you experience now, against your memory of how a vehicle rode 8 yrs ago, and expect the forum to diagnose your perceived differences? Lol

 

The road between my house and my folks' place is a very well known mountain highway in California. With the KDSS I can drive with traffic with no noticeable body sway and more confident than some sedans I own. It's that good.

 

In 2015 I bought a new Trail Premium with KDSS and last year I bought a new ORP with KDSS so I could sell the 2015 to my daughter in Denver because she needed a new car. Both cars have 35psi in the tires and I would say they drive exactly the same except the 2023 is slightly firmer but the 2015 has 60,000 miles on it - they both drive fantastic! Sounds like there might be something else going on?

 

Yeah there is something else going on. My 23 with the KDSS rides phenomenally. The only car I have owned that is more cushy are the XV20 camry's.

 

It’s interesting you mentioned cushy. I almost figured having very strong/thick swaybars could lead to ride characterstics that would be perceived as harsher/firmer.

Especially since sometimes you hear people that remove swaybars talk about how much cushier the ride feels after removal. I would think that would be true, because each side is truly independent without a swaybar, allowing each corner to individually respond to road imperfections without transmitting the force to the other side. Transmitting the force to the other wheel is what a swaybar does to keep a car itself level during extended side-loads in a turn, but ironically, they can cause swaying motions in the actual occupants at lower speeds when riding over uneven rougher surfaces.

No doubt, the dynamic handling turns to shit with swaybars removed, but I would suppose it’s much cushier on rough uneven surfaces going straight ahead. That’s the reason why I’m theorizing that maybe the OP’s older 4runner felt different…because maybe the kDSS lost fluid (which can happen given the pics of corrosion I’ve seen on the kdss manifold/accumulator). If the system was drained of fluid, then maybe the rams could not hold the swaybar in place to so that it could transmit the forces to the other side. I suspect the vehicle would behave as if it doesn’t have a swaybar.

Full disclosure, I’m not sure if KDSS actually fails that way when it loses fluid, but it seems reasonable to think the ram could not hold the swaybar without fluid.

 

Our 2023 ORP with KDSS (and the 2015 too) drives curvy mountain roads here in Colorado like a dream - kinda like a luxury car that you can take off-roading! The only better handling cars that I have owned were highly modified mid-1970s BMW 2002s - lowered suspensions, bigger sway bars, Bilstein shocks, wider wheels and tires, quick ratio steering box, polyurethane bits instead of rubber in the suspension; well, you get the idea. That's how good I think the 4Runner handles for such a large vehicle and I credit the KDSS suspension

 

I hope there is something else going on. My '24 KDSS rides very harsh. Perhaps something changed in 24 that earlier models don't have?

 

Highly unlikely that anything changed with KDSS in 2024 I think

 

OP Ghost

 

What tires did your Trail have? I went from a 2016 Tacoma Sport 6MT to a 2020 Tacoma Sport 6MT and the Toyo's that came on the 2020 rode much worse than the Firestone's that came on my 2016.

Also the Toyo's that came on my 2023 4Runner ORP did not ride nice either. Just installed Cooper Discoverer Rugged Trek's in 285/70R17 and the ride is much smoother.