2WD, KDSS, Trac Control Off Road Questions

R

rkwfxd

New member
Howdy folks. I have two questions from this weekend's off road trip and I can't find a definitive answer.

Briefly - I did about 25 miles of light off road trail this weekend in two wheel drive the entire time. Never even aired down my tires ('18 TRDORP with KDSS).

First question - does the KDSS system "release" while creeping along in 2WD? The ride just seemed really rough, rougher than it should have. This is the second time I have taken this trail and during the first time I was playing with crawl control, A-TAC, Rear Locker, 4-Hi, 4-Lo etc.... the ride was rough but it seemed rougher this time. Might be all in my head because I was flying solo the first time but this weekend I had by wife and son with me.

Second question - is there any active traction control at all in 2WD? I got to a section of moguls and as I was crossing it I had to peddle the throttle a bit each time I lost traction. It felt as if the spinning wheel was moving from one side to the other as if traction control was kicking in.

TIA
 
Register to hide this ad
rkwfxd said:
Howdy folks. I have two questions from this weekend's off road trip and I can't find a definitive answer.

Briefly - I did about 25 miles of light off road trail this weekend in two wheel drive the entire time. Never even aired down my tires ('18 TRDORP with KDSS).

First question - does the KDSS system "release" while creeping along in 2WD? The ride just seemed really rough, rougher than it should have. This is the second time I have taken this trail and during the first time I was playing with crawl control, A-TAC, Rear Locker, 4-Hi, 4-Lo etc.... the ride was rough but it seemed rougher this time. Might be all in my head because I was flying solo the first time but this weekend I had by wife and son with me.

Second question - is there any active traction control at all in 2WD? I got to a section of moguls and as I was crossing it I had to peddle the throttle a bit each time I lost traction. It felt as if the spinning wheel was moving from one side to the other as if traction control was kicking in.

TIA
Click to expand...

Did you air down your tires the first time you took that trail?

KDSS and traction control work the same whether in 2WD or 4WD.
 
your ride was rough because you didn't air down your tires

you do have traction control in 2wd

KDSS engages/disengages based on speed and also other factors like degree of turn, yaw, pitch...


don't do trails in 2wd, it just unnecessarily damages them and causes washboarding which is annoying. use 4wd on trails even if you don't "need" to.
 
TEujunga said:
Did you air down your tires the first time you took that trail?

KDSS and traction control work the same whether in 2WD or 4WD.
Click to expand...

No, I did not.

OK so it wasn't just my imagination - the Trac Con was actually looking for traction on the uneven surface in 2WD - pretty cool. I am more and more impressed with this thing the more I drive it.

Thank you.
 
KDSS softens the ride when offroading below 12mph, independent of 2/4wd.

The 5th gen definitely softens up as well when you have a load in it. I noticed a big difference just offroading with our luggage in the trunk compared to leaving it in our hotel in the Sierras this weekend. Find passenger(s) or luggage for the rear seats next time, lol.

Air down. The 5th gen with modern tires really likes to be at 35-40psi for highway ride and general mpg benefits... which sucks on trails. On trails you want to be under 30psi usually. Just wish the 5th gen had a central tire inflation system like Hummer H1s!
 
e60ral said:
your ride was rough because you didn't air down your tires

you do have traction control in 2wd

KDSS engages/disengages based on speed and also other factors like degree of turn, yaw, pitch...


don't do trails in 2wd, it just unnecessarily damages them and causes washboarding which is annoying. use 4wd on trails even if you don't "need" to.
Click to expand...

Good advice but folks drive CARS on this "trail." I promise I did not do any damage.
 
BobsTrail said:
I have mixed feelings about using 4WD on simple trails, it locks the front and read diffs
Click to expand...

If you mean it locks the front and rear driveshaft's to the same speed yes, it does not in anyway lock the front and rear differentials. I assume you meant shafts but its a confusing statement.

Regardless I paid for 4x4 and I would much rather have it engaged, and not get into trouble in the first place vs. get into trouble with 2wd and hope it is able to get me out.

PS Not directed at the OP but just air down folks, its easier on the trails, its easier on the vehicle, its easier on the passengers....win, win , win
 
I don't like to engage 4wd on the hwy until absolutely necessary but like to get into 4wd as soon as I hit dirt. I also like to put it in MTS: Mud, Sand, Dirt for less aggressive traction control on easy trails, or fire roads.
Exercise that drivetrain! IMO, ABS works very poorly, almost to the point of dangerous, on dirt in 2wd.
 
OTOH, 4x4 decreases mpg by a lot, so as long as you drop your pressure a little, there's nothing wrong with 2wd. Go with what the surface dictates, but if it's firm, dropping tire pressure and loading your car a bit more are probably the quickest fixes. The 4runner is designed to run with a little weight in it. That's why unloaded it has that forward rake, so that when you toss 200 lbs in the back, it doesn't look squatted there.
 
1996_Valencia_Owen said:
OTOH, 4x4 decreases mpg by a lot, so as long as you drop your pressure a little, there's nothing wrong with 2wd. Go with what the surface dictates, but if it's firm, dropping tire pressure and loading your car a bit more are probably the quickest fixes. The 4runner is designed to run with a little weight in it. That's why unloaded it has that forward rake, so that when you toss 200 lbs in the back, it doesn't look squatted there.
Click to expand...

That makes so much sense. In the short amount of time I've had my car I've driven it on highways at speed, freshly paved roads at 35-50 mph, paved roads in horrible condition at 25-40 mph, and somewhat bumpy dirt/gravel roads at 10-30 mph. Crawling on uneven ground is great. I can really feel the KDSS balance out the sway. It also handles great on the highway and freshly paved roads, but I noticed that on crappy paved roads and dirt/gravel roads the ride feels very firm to the point where I can feel every bump, crack or undulation. It's like the suspension is working crazy hard and creating more vibration than I would expect. I notice this in H2 and H4. H2 on paved roads and H4 off-road.

Is this normal for KDSS? Could I not be used to the body on frame design? We're going on vacation next week and will be loading up the car with people and supplies so will see if the ride softens up with load. I don't really want to lower the tire pressure when driving on pavement, which I do 80-90% or the time. I can see that being a fix when off-road, but not really a fix for pavement.
 
Last edited:
Somebody who knows better, correct my if I'm wrong.

The way I understand it, the KDSS system is a speed sensitive "ON" or "OFF" for the sway bars. It allows us to have beefy sway bars for road driving, really cutting into body roll. However, to my knowledge it doesn't really have an effect on how hard/soft the suspension is. Sway bars "link" the suspension so there cannot be a major difference in articulation from side to side. For example, if you go off a curb straight, both front wheels extend downward together, but if you go off at an angle one side wants to extend down first, then the other. Sway bars limit this difference. This is good for cornering on smooth roads because it keeps the vehicle from leaning to the outside of the turn. It's bad for offroading because the suspension cannot work as independently, like if you roll over a rock with your right front tire, the sway bar won't let the right front compress up all the way because the left front is still down. Some people remove their sway bars completely if they don't spend much time driving at higher speeds. With KDSS at low speeds the sway bars "release", which allows for more independent suspension articulation.

For me, I feel the KDSS working when driving fast. My KDSS 4Runner corners better than any other 4x4 I've driven that isn't designed for roads (like a Porsche Cayenne...). I don't really notice the offroad effects of the KDSS being "off" unless I'm driving slowly on pretty uneven terrain, where the wheels are all going up and down at different rates.

Now that I think about it, the KDSS might feel stiffer because it is limiting articulation. The suspension wants to go up/down further but is limited, so it's more jarring? If that's the case, slow down a tad and see if it smoothes out. See if you can tell when the KDSS turns off.
 
Thrasher_S said:
Now that I think about it, the KDSS might feel stiffer because it is limiting articulation. The suspension wants to go up/down further but is limited, so it's more jarring? If that's the case, slow down a tad and see if it smoothes out. See if you can tell when the KDSS turns off.
Click to expand...

That's kinda what I was thinking. I see the benefit of KDSS at both ends of the spectrum, highway speeds/higher speed cornering on pavement and crawling or driving at slow speeds through uneven/rough terrain. It's the firm/stiff ride going 15-50 mph on gravel/dirt roads or crappy/cracking paved back roads.

Just trying to understand it a little better and see if this in a normal function of KDSS at these speeds or road surfaces, before I have the dealer take a look at it.
 
cwagner said:
That makes so much sense. In the short amount of time I've had my car I've driven it on highways at speed, freshly paved roads at 35-50 mph, paved roads in horrible condition at 25-40 mph, and somewhat bumpy dirt/gravel roads at 10-30 mph. Crawling on uneven ground is great. I can really feel the KDSS balance out the sway. It also handles great on the highway and freshly paved roads, but I noticed that on crappy paved roads and dirt/gravel roads the ride feels very firm to the point where I can feel every bump, crack or undulation. It's like the suspension is working crazy hard and creating more vibration than I would expect. I notice this in H2 and H4. H2 on paved roads and H4 off-road.

Is this normal for KDSS? Could I not be used to the body on frame design? We're going on vacation next week and will be loading up the car with people and supplies so will see if the ride softens up with load. I don't really want to lower the tire pressure when driving on pavement, which I do 80-90% or the time. I can see that being a fix when off-road, but not really a fix for pavement.
Click to expand...
Its bumpy at speed on rough roads because KDSS has big thick sway bars that transfer that motion. If you have a long stretch of dirt road doing more than 25 or 30mph all you have to do is drop your air pressure about 5psi and it will be comfortable

Sent from my SM-G930V using Tapatalk
 
You must log in or register to reply here.

Members online

Total: 761 (members: 5, guests: 756)

Forum statistics

Threads
278,314
Messages
3,554,096
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top