KDSS Conundrum (2 Viewers)

[linuxgod]

Mine leaned when dead stock with 100k miles, and it did so until I put new springs under it. Zero changes to the KDSS system other than balancing.

In the manual they are allowed to lean by a surprising amount, though I can’t recall the number at the moment.

FSM says +/-15mm, so about 5/8”

 

[bloc]

FSM says +/-15mm, so about 5/8”

Ah, less than I remember. I think my 2013 had almost 2” difference left to right when I got it. No amount of fiddling with KDSS had an effect. Putting it on new springs did.

 

[2021 LC200]

Ah, less than I remember. I think my 2013 had almost 2” difference left to right when I got it. No amount of fiddling with KDSS had an effect. Putting it on new springs did.

Did you buy new?

I have had zero issues with stock springs, including installing airbags (which should not affect things left or right).

 

[bloc]

Did you buy new?

I have had zero issues with stock springs, including installing airbags (which should not affect things left or right).

I got basically zero-mile take-off shocks and struts from someone else's new 2021 200 build, to replace the Kings when I removed them.

Stock springs are great, but don't age well. I suspect it's because they are so flexy for the weight of the vehicle.

 

[Goldbug]

Well, after adjusting KDSS three times, it’s kept going back, so I think @bloc, @daneo and others are right: it’s not a KDSS issue.

I took the wheels off last night and did a bunch of measurements. The springs & shocks are the same length, but the passenger side hub hangs about an inch and a 1/4 lower than driver which corresponds with the pass side being higher when the wheels are on.

Thoughts on where to start? I guess I could adjust the length of the shocks with the collars on the bottom but if they’re currently the same, that doesn’t seem quite right. I admit that I must have screwed something up in the install and certainly want to get this fixed before driving out to LCDC X!

@crikeymike?

 

[2021 LC200]

Looks like shocks would be collapsed when standing on its own wheels. I would think spring force left right is not equal or balanced for what the 200 needs. Can they be changed sides? That could be low cost and worth a try.

 

[linuxgod]

Looks like shocks would be collapsed when standing on its own wheels. I would think spring force left right is not equal or balanced for what the 200 needs. Can they be changed sides? That could be low cost and worth a try.

Not sure about the Dobinson’s coils but factory coils are the same up front left or right, both length and 600# stiffness. In the rear the passengers side spring is longer though they are the same 170# stiffness.

 

[TLC2013]

I spent far too much time and energy chasing a suspension lean. Anyting under 5/8" i wouldnt worry about; Which is within toyota's specifications. One thing i noticed is that when i attempted to level the rear, i was about 3/4" off, by adding rim packers (5-10mm spacers) there was a direct correlation to the height changing at the opposite front side. For example increasing the rear driver side would impact the height of the front passenger.
Also be sure your drive way is completely level when taking measurements, I found out my driveway is no were near as level as i had assumed and it was definitely playing a role in why i kept chasing a kdss lean.

Dobinson makes 1/4" front strut spacers. I am using these to add some additional height back after my suspension settled a bit over the last 5 years.

 

[crikeymike]

Well, after adjusting KDSS three times, it’s kept going back, so I think @bloc, @daneo and others are right: it’s not a KDSS issue.

I took the wheels off last night and did a bunch of measurements. The springs & shocks are the same length, but the passenger side hub hangs about an inch and a 1/4 lower than driver which corresponds with the pass side being higher when the wheels are on.

Thoughts on where to start? I guess I could adjust the length of the shocks with the collars on the bottom but if they’re currently the same, that doesn’t seem quite right. I admit that I must have screwed something up in the install and certainly want to get this fixed before driving out to LCDC X!

@crikeymike?

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I've never owned a 200 series, but the 5th gen 4runner with KDSS does the same thing, one side gets more down travel than the other up front. That won't affect anything until you're about to lift a tire off the ground.

The front and rear springs from Dobinsons are offset heights. The front marked left and right should be installed that same way, and the rears should be matched up with the stock ones that come off. Taller one goes on the taller take off side.

Drive the vehicle down to a gas station or somewhere else that's level and remeasure. Someone told me a few years back that KDSS "turns off" under a certain speed (I can't remember), so if the vehicle is leaning when it turns off, it could hold that position when you go up and into your driveway and garage. The on/off switch that DR KDSS makes for the 5th gen and GX460 would allow it to bypass that feature.

 

[Goldbug]

I've never owned a 200 series, but the 5th gen 4runner with KDSS does the same thing, one side gets more down travel than the other up front. That won't affect anything until you're about to lift a tire off the ground.

The front and rear springs from Dobinsons are offset heights. The front marked left and right should be installed that same way, and the rears should be matched up with the stock ones that come off. Taller one goes on the taller take off side.

Drive the vehicle down to a gas station or somewhere else that's level and remeasure. Someone told me a few years back that KDSS "turns off" under a certain speed (I can't remember), so if the vehicle is leaning when it turns off, it could hold that position when you go up and into your driveway and garage. The on/off switch that DR KDSS makes for the 5th gen and GX460 would allow it to bypass that feature.

Thanks. I've driven it a lot lately and the imbalance has been impressively consistent, so I don't think it's a KDSS height or speed thing, but admittedly I'v only really measured it at home, so I'll try that. I need a car wash badly after our last snow storm, so good excuse. If all else fails, I suppose I can try to swap the front springs, but it was pretty intense the first time and I do think I was careful about left and right and installing correctly. Do you know where it is marked so I could look?

What do you think about adjusting the collars/rings at the bottom of the shocks?

 

[crikeymike]

Thanks. I've driven it a lot lately and the imbalance has been impressively consistent, so I don't think it's a KDSS height or speed thing, but admittedly I'v only really measured it at home, so I'll try that. I need a car wash badly after our last snow storm, so good excuse. If all else fails, I suppose I can try to swap the front springs, but it was pretty intense the first time and I do think I was careful about left and right and installing correctly. Do you know where it is marked so I could look?

What do you think about adjusting the collars/rings at the bottom of the shocks?

There are white labels on the top or bottom of each spring that say it. Photo attached for reference.

Yes, you can adjust the preload, but that can be quite hard to do on the vehicle. Swapping the whole strut assembly left to right would actually probably be easier. But also worth checking the rear coils first, as the previous guy said, it has an opposite effect on the lift height on the opposite corner that changes. Lowering the right rear can raise the left front, as an example.

 

[bloc]

Someone told me a few years back that KDSS "turns off" under a certain speed (I can't remember), so if the vehicle is leaning when it turns off, it could hold that position when you go up and into your driveway and garage. The on/off switch that DR KDSS makes for the 5th gen and GX460 would allow it to bypass that feature.

The Prado/150 version of KDSS has this feature but the 200-series does not. There are no electrical inputs, only a pressure sensor on the 2008-~2010 models.

 

[crikeymike]

The Prado/150 version of KDSS has this feature but the 200-series does not. There are no electrical inputs, only a pressure sensor on the 2008-~2010 models.

Oh, that's good. Thanks for that info.

 

[bloc]

Oh, that's good. Thanks for that info.

If you’re curious I cut open a J200 KDSS valve to get a better understanding of how it operates. Some pretty interesting stuff is going on inside.

Anatomy of a KDSS valve

I think you guys and gals are gonna like this.. HUGE thanks to @jimoldguy who shipped me his rust-damaged KDSS valve after it was replaced for him with a new one. That can't have been cheap. Fortunately for me he kept the old one, and when I PM'd asking if he'd send it for a project I'm working...

forum.ih8mud.com

 

[AnyMal]

I spent far too much time and energy chasing a suspension lean. Anyting under 5/8" i wouldnt worry about; Which is within toyota's specifications. One thing i noticed is that when i attempted to level the rear, i was about 3/4" off, by adding rim packers (5-10mm spacers) there was a direct correlation to the height changing at the opposite front side. For example increasing the rear driver side would impact the height of the front passenger.
Also be sure your drive way is completely level when taking measurements, I found out my driveway is no were near as level as i had assumed and it was definitely playing a role in why i kept chasing a kdss lean.

Dobinson makes 1/4" front strut spacers. I am using these to add some additional height back after my suspension settled a bit over the last 5 years.

Same. And with AHC it’s an even bigger mess to sort out. They all lean. First thing i sorted after 21” wheels.

 

[Goldbug]

There are white labels on the top or bottom of each spring that say it. Photo attached for reference.

Yes, you can adjust the preload, but that can be quite hard to do on the vehicle. Swapping the whole strut assembly left to right would actually probably be easier. But also worth checking the rear coils first, as the previous guy said, it has an opposite effect on the lift height on the opposite corner that changes. Lowering the right rear can raise the left front, as an example.

View attachment 3603513

Ok. The rear is level so I haven’t looked at it, but I will, to first make sure I installed them correctly. Of course I tore off those labels on the shocks but I’m 99% sure I did them on the right sides.

 

[bloc]

One thing to keep in mind.. the fender lips can be expressed as a plane. Meaning as long as the vehicle isn't bent, and you are on a truly flat surface, the rear can't be level but the front crooked.

@TLC2013 was right to bring up most outdoor slabs of concrete aren't truly planar enough to take these measurements. An auto shop or warehouse floor is probably a much better way to dial this in.

 

[rlynch356]

The driver's side spring should be pretty easy to get in and out but yes the passenger's side is a PITFA. I've tried all sorts of tricks disconnecting the sway bar, panhard rod, KDSS end link, etc and it always sucks to get it back together.

Not sure if its been suggested but just did this (twice on 2 different trucks, recently)... for the passenger rear spring I use a bottle jack between the axle and bump stop (use something flat on the bump stop, I have a safe jack..)...

makes it pretty easy and quick.

Also Re: Lean - we typically need to reverse the springs from the Australian position, all of the instructions for Australian focused and made brands are written for the Australian and South African local market. They have to account for the driver & a full tank of full on the right side of the truck.

Also did this on mine, no appreciable lean with an OME Nitrocharger kit & OME UCA's... (also aligned fine the first time as well)

Just letting it sit with the valves open "may" help but I would really shake it with the valve's open and let it return to the neutral for a minute or two, then close the valves...I seriously doubt how long they are open makes any difference since its hydraulic pressure which your working with.

 

[bloc]

Not sure if its been suggested but just did this (twice on 2 different trucks, recently)... for the passenger rear spring I use a bottle jack between the axle and bump stop (use something flat on the bump stop, I have a safe jack..)...

makes it pretty easy and quick.

Also Re: Lean - we typically need to reverse the springs from the Australian position, all of the instructions for Australian focused and made brands are written for the Australian and South African local market. They have to account for the driver & a full tank of full on the right side of the truck.

Also did this on mine, no appreciable lean with an OME Nitrocharger kit & OME UCA's... (also aligned fine the first time as well)

Just letting it sit with the valves open "may" help but I would really shake it with the valve's open and let it return to the neutral for a minute or two, then close the valves...I seriously doubt how long they are open makes any difference since its hydraulic pressure which your working with.

If we really want to put it through the range we can drive one tire up onto blocks with the valves open. Or even better, diagonally opposed ramps. Then get it back onto flat ground and lock everything in by closing the valves.

Due to the main KDSS valve design small imbalances should sort themselves out eventually. Thing is, this will use whatever the vehicle is sitting on as a reference for “flat.” If it isn’t actually flat, then we drive away onto flat road, yes we can get a lean until the system can balance itself to those conditions.

Cycling KDSS then locking it in on a truly flat surface is the best way to eliminate it as a contributor to lean.

 

[2021 LC200]

Due to the main KDSS valve design small imbalances should sort themselves out eventually. Thing is, this will use whatever the vehicle is sitting on as a reference for “flat.” If it isn’t actually flat, then we drive away onto flat road, yes we can get a lean until the system can balance itself to those conditions.

Cycling KDSS then locking it in on a truly flat surface is the best way to eliminate it as a contributor to lean.

Exactly how KDSS works on a 200 series. Great it is just a simple hydraulic system and very happy how it improves on road handling in corners and will allow for full articulation offroad.

However a sloped or more so angled drive way would not be a happy environment for a 200 with KDSS or a garage with a low point for a drain or otherwise significant uneven floor.

Never consider something like these (or more angled) could be a problem. It is pretty unusual though.

Howe