KDSS - Leaning when driving

[Nickk6]

I tried searching for a KDSS lean or sway while driving and couldn't find anything when going thru the other KDSS lean threads/google searches, so here goes:

My dad was driving behind me and I was in my GX. He said when I turn right or the road curves right, my car is stable and remains flat, but when I turn left or go around a left turn the car sways a lot more. I never paid attention to this, but now I notice it and its visible by looking at the hood and swaying the car left and right. I'd ask this on the GX forum, but those guys are not really lifting their trucks. I am wondering if my lift could have something to do with this or is it a problem with KDSS? Possibly blown shock on the side that's sagging? Vehicle is a 2016 GX460 without air suspension and Icon lift.

Thanks for any feedback (unless you are a smart ass who didn't read my post and assumed this was another regular kdss lean thread)!

 

[Grape Ape]

I'm gonna sit right here and wait for the flaming to commence seeing if you search "KDSS lean" there are 540 results

 

[bigbadpoppa]

Trade it in for a 4runner. Problem solved.

 

[tristero]

First, do you have a premium with the adaptive variable suspension?

 

[Nickk6]

I'm gonna sit right here and wait for the flaming to commence seeing if you search "KDSS lean" there are 540 results

Yeah, they all have issues with it parked, I am talking about driving. I'm not getting a clear answer if this is the same thing, but if it requires flaming go for it, glad I can provide something for you to do with your time besides helping.

KDSS Balance and fixing a KDSS lean - Project 200

 

[Nickk6]

First, do you have a premium with the adaptive variable suspension?

Base model with base suspension

 

[mo_mo]

I tried searching for a KDSS lean or sway while driving and couldn't find anything when going thru the other KDSS lean threads/google searches, so here goes:

My dad was driving behind me and I was in my GX. He said when I turn right or the road curves right, my car is stable and remains flat, but when I turn left or go around a left turn the car sways a lot more. I never paid attention to this, but now I notice it and its visible by looking at the hood and swaying the car left and right. I'd ask this on the GX forum, but those guys are not really lifting their trucks. I am wondering if my lift could have something to do with this or is it a problem with KDSS? Possibly blown shock on the side that's sagging? Vehicle is a 2016 GX460 without air suspension and Icon lift.

Thanks for any feedback!

1st, there is no 'shock' to the KDSS system. There is a single piston for the front sway bar and a second piston for the rear sway bar. A valve opens or closes based upon an electric signal which allows the piston to move (closed valve = no fluid movement, open valve = fluid movement). So any 'blown shock' would be a standard suspension shock failure. I'll stop there on this subject and allow you to google more details on suspension shocks if needed. If a piston fails in the KDSS, your sway bar will not increase lateral spring stiffness in both left/right directions equally. At least this is how I think the system works on the 2010+ KDSS 4Runners.

2nd, I have noticed that if I turn-in, with the steering wheel, a bit slowly and at low speed, the vehicle seems to have more roll than if I enter the same turn fast and turn-in fast. I attribute this to the KDSS valve being open when I initiate the turn at slow speed and it opts to not close the valve (or maybe the piston is at an internal stop) so the vehicle never flattens out as if I had entered the turn quickly.

Related to #2, you may turn left vs right at different rates instinctively and that could contribute to the KDSS system allowing the piston to move or not.

There are a couple of Toyota videos on youtube that animate the KDSS system. I think Toyota has made a couple of different versions over the years and that the newer systems have an electronic valve control based upon speed, so if you're over a specific speed then it should provide the same amount of rigidity left or right.

Now that you've noticed this feature/bug, please test and evaluate and report back!

 

[Nickk6]

1st, there is no 'shock' to the KDSS system. There is a single piston for the front sway bar and a second piston for the rear sway bar. A valve opens or closes based upon an electric signal which allows the piston to move (closed valve = no fluid movement, open valve = fluid movement). So any 'blown shock' would be a standard suspension shock failure. I'll stop there on this subject and allow you to google more details on suspension shocks if needed. If a piston fails in the KDSS, your sway bar will not increase lateral spring stiffness in both left/right directions equally. At least this is how I think the system works on the 2010+ KDSS 4Runners.

Sorry, I was not referring to the Hydraulic as being blown, I was wondering if a shock as in my suspension shock being blown possibly allowing a more noticeable lean (I have no visible indications of such).

Again as I keep reading more articles, everyone is complaining about their vehicle leaning when parked, all the repeated KDSS threads repeat the same thing, I've not seen anyone asking this question specifically; leaning while in motion, not when parked!

2nd, I have noticed that if I turn-in, with the steering wheel, a bit slowly and at low speed, the vehicle seems to have more roll than if I enter the same turn fast and turn-in fast. I attribute this to the KDSS valve being open when I initiate the turn at slow speed and it opts to not close the valve (or maybe the piston is at an internal stop) so the vehicle never flattens out as if I had entered the turn quickly.

Related to #2, you may turn left vs right at different rates instinctively and that could contribute to the KDSS system allowing the piston to move or not.

There are a couple of Toyota videos on youtube that animate the KDSS system. I think Toyota has made a couple of different versions over the years and that the newer systems have an electronic valve control based upon speed, so if you're over a specific speed then it should provide the same amount of rigidity left or right.

Now that you've noticed this feature/bug, please test and evaluate and report back!

Its the same reaction at lower speeds as higher speeds, its a noticeable tilt at 45-55mph when swaying back and fourth on an open road.

 

[1000MPH]

Roads are not flat. Left turns are mostly off camber since you are in the right lane.

 

[mo_mo]

Maybe take a look at your suspension bushings including the KDSS bushings. The KDSS should have equal system stiffness left/right at a given speed, so maybe a hard stop on a top/bottom of a bushing is sloppy and giving you more lean/sway in a given direction. How does your vehicle measure when on level ground with a full tank of gas fender well to centerline of the hubs? Is there more than a .25 difference left to right?

 

[Nickk6]

Maybe take a look at your suspension bushings including the KDSS bushings. The KDSS should have equal system stiffness left/right at a given speed, so maybe a hard stop on a top/bottom of a bushing is sloppy and giving you more lean/sway in a given direction. How does your vehicle measure when on level ground with a full tank of gas fender well to centerline of the hubs? Is there more than a .25 difference left to right?

Only about 3/16" difference in my garage. One of the sway bar bushings looks a little beat up, but doesn't look like it would cause this issue. I think I may need to go to the dealership to get their opinion :rofl: