Correcting a KDSS lean

[bloc]

Maybe I’m the only one that feels this way but this “fix” is a bandaid at best. Improperly loading the KDSS hydraulic system to apply pressure to the suspension in an attempt to correct a lean caused by something else puts constant loads on it that I’m pretty sure toyota didn’t design it for.

If you’ve already opened the balance screws on level ground your lean is caused by something else. Springs, suspension bushing position when torqued, drastically uneven vehicle loading.. seems best to address that properly.

 

[randalldavan]

Did you fix this? Mine is lower on the front Left (driver) as well ... Wondering if the drive up the board trick would be board under passenger front? Rear? Measure the highest?

I have the same problem, a front left/driver side lean. Ever fix this?

 

[fuqtodd]

I too have a lean on my 2014 (130K) - left front lower than right front by roughly 1". Was able to get the KDSS screws open and lifted the drivers side with a floor jack, then tightened the screws. Lean was gone for a few days, then returned. I have a lift on order with shocks, springs and UCA's and am hoping that corrects things. Any other ideas would be appreciated as I'm driving cross country next month.

 

[bloc]

I too have a lean on my 2014 (130K) - left front lower than right front by roughly 1". Was able to get the KDSS screws open and lifted the drivers side with a floor jack, then tightened the screws. Lean was gone for a few days, then returned. I have a lift on order with shocks, springs and UCA's and am hoping that corrects things. Any other ideas would be appreciated as I'm driving cross country next month.

I'd order some trim packers too to fine tune the level when you install the lift, vs realize it isn't level then have to wait on parts.

I wrote the above post quite a while ago and have become even more convinced in what I said, having dissected a KDSS valve to understand how it works in the meantime.

 

[Madtiger]

Besides it being a cosmetic issue, is there a handling/off-road/wear & tear issue with a KDSS/AHC lean?

 

[bloc]

Besides it being a cosmetic issue, is there a handling/off-road/wear & tear issue with a KDSS/AHC lean?

Eventually it can impact clearance over objects and suspension travel.. And I'd guess a very mild uneven weight distribution. But having zero lean is difficult and most vehicles have some when you measure closely.

 

[linuxgod]

Besides it being a cosmetic issue, is there a handling/off-road/wear & tear issue with a KDSS/AHC lean?

I would assume it would impact your potential articulation (or really just where you start in the process), in the sense that your over-compressed wheels won't compress as much and your over-extended wheels won't extend as much. The wheels should have more travel in the opposite direction though. More to the point because your "neutral" position isn't really neutral I'd expect possibly more suspension/bushing/CV wear particularly on the taller side, but I wouldn't expect any KDSS impact directly.

 

[linuxgod]

I too have a lean on my 2014 (130K) - left front lower than right front by roughly 1". Was able to get the KDSS screws open and lifted the drivers side with a floor jack, then tightened the screws. Lean was gone for a few days, then returned. I have a lift on order with shocks, springs and UCA's and am hoping that corrects things. Any other ideas would be appreciated as I'm driving cross country next month.

Is it front and rear that's off?

I found my front lean was impacted by the rear, meaning when I fixed the lean caused by the rear springs being swapped into the wrong sides that the front corrected itself. Assuming your springs are set up correctly I'd start with trim-packers to level the rear before trying to fix anything else (particularly up front) as you might be surprised the result.

FWIW I never had any success fixing my KDSS lean as described in this thread. Any change was negligible compared to the total amount mine was off and any "fix" reverted itself rather quickly. I could see how this trick might help if your lift was installed without opening the KDSS valves (as you'd basically be correcting for that) but understanding KDSS and subsequently having seen @bloc tear one apart I don't see how this would help in the long run.

 

[TeCKis300]

To a degree, some suspension lean on slinkier longer travel trucks, 4x4s, and others is completely normal. ~1" deviation is within normal, and may not even be consistent when re-measuring. As others have said, the KDSS lean concept is a fallacy. KDSSs function is a sway bar and should not impart lean in and of itself at rest. Therefore using it to correct lean, is futile, and will never achieve the desired outcome for long.

Lean is a function of the main springs sagging over time. Whether a heavier corner, or weaker spring, or systemic parking on a grade, it'll eventually take a set. Over longer periods of time, continue to sag further in that direction. So even if one achieves level, given enough time, it'll develop a lean again. So call it leveling maintenance if you will. Best way to fix it is directly via trim packers. We don't have as many tools to do that for a sagging front spring, but 5-10mm trim packers are easy to add to the rear. And/or new springs.

In use, a lean is near imperceptible to affect any drivability issues. And could vary with gas volume and load out. It's like tire pressures where some geek out and aim for some perceived need for exact PSI precision, when there's other variables that play a bigger part.

Aiming for about .5" delta is probably as level as is worthwhile.

 

[bloc]

So call it leveling maintenance if you will.

This is a great way to think about it.

Rear springs aren’t very expensive at about $130 each (if my memory serves) and throwing a new pair at it after five years is a small cost of ownership. Also pretty easy to install with some tall jack stands.

 

[AnyMal]

Is it front and rear that's off?

I found my front lean was impacted by the rear, meaning when I fixed the lean caused by the rear springs being swapped into the wrong sides that the front corrected itself. Assuming your springs are set up correctly I'd start with trim-packers to level the rear before trying to fix anything else (particularly up front) as you might be surprised the result.

FWIW I never had any success fixing my KDSS lean as described in this thread. Any change was negligible compared to the total amount mine was off and any "fix" reverted itself rather quickly. I could see how this trick might help if your lift was installed without opening the KDSS valves (as you'd basically be correcting for that) but understanding KDSS and subsequently having seen @bloc tear one apart I don't see how this would help in the long run.

Just match your rear springs.
From factory your drivers side rear is weaker than the opposite corners.

You need to load match your rear springs because Toyota ships the 200 for RHD markets and throws every other market beneath that in priority.
The only time a spring offset is required is when both the driver and gas tank are on the same side of the vehicle.
If you truck is LHD, its probably leaning to the left unless its older.

 

[linuxgod]

Just match your rear springs.
From factory your drivers side rear is weaker than the opposite corners.

You need to load match your rear springs because Toyota ships the 200 for RHD markets and throws every other market beneath that in priority.
The only time a spring offset is required is when both the driver and gas tank are on the same side of the vehicle.
If you truck is LHD, its probably leaning to the left unless its older.

In the US the passenger's (right) side OEM spring is longer than the driver's (left) side. I think that spring setup (longer on the right) is true around the globe regardless of where the drive sits. The Tough Dog kit I bought had different length springs. I installed the taller spring (which was marked RH) on the driver's side at first, based on the TD instructions which said to reverse them for US models, but that resulted in about 1.5" of lean (very high driver side). Swapping so the shorter spring was on the driver's side and the longer one on the passenger's side leveled out my ride within maybe 3/8".

Right now I'm level but my suspension has 55k miles on it and I have a drawer setup with tools on the driver's side. I do agree the weight of the driver and fixed cargo will impact your lean a bit so if you add drawers, move your spare to a swingout, etc all of that can impact your lean. For most folks just use the springs that came with your kit, putting the longer spring on the right side, and then use trim packers to fine-tune your setup.

 

[AnyMal]

I think that spring setup (longer on the right) is true around the globe regardless of where the drive sits.

This is exactly the problem and is a factory flaw for our trucks. There is no need for any offset in a Left Hand Drive market.
It setup that way only because RHD market is the only time you will have one occupant (driver) on the same side as a full (never) gas tank.

Wether you use two driver side or two longer passenger side (US) springs is up to you.
I used two of the stronger springs myself. It did nothing but improve things all around.

 

[residualboulders]

my .02. After opening KDSS valves multiple times trying different methods to get rid of the lean, nothing worked. As @linuxgod mentioned there is a longer A spring for the drivers side and B for Passenger (according to ARB BP51 Instructions). My Toyota dealer installed as per BP51 instructions. They said it's important that the taller spring be on the side of the fuel tanks which is our passenger side. After no success getting rid of my lean with various KDSS adjustment attempts, I swapped the taller A to US drivers side and my rig sits perfectly level now. (2021 with 10k miles). After discussing with Don at ARB USA he confirmed this is how it should be installed in the US. Interesting since I know there are some out there that have the taller spring on the passenger side with no lean.

for reference, my post about all things I tried to eliminate lean.

Builds - Wyoming HE Build

ARB install complete. Man that was quite the project. Worked on it over a few days mostly alone and the instructions left a few details out that took me a while to figure out. Turned out pretty good though I think. Suspension feels better already (having been preloaded for it) so that was nice...

forum.ih8mud.com

 

[linuxgod]

my .02. After trying opening KDSS valves multiple times trying different methods to get rid of the lean, nothing worked. As @linuxgod mentioned there is a longer A spring for the drivers side and B for Passenger (according to ARB BP51 Instructions). My Toyota dealer installed as per instructions saying that it is important that the taller spring be on the side of the fuel tanks which is our passenger side (Aussie drivers) so he followed ARB instructions. After having no success getting rid of my lean I swapped the taller A to US drivers side and my rig sits perfectly level now. (2021 with 10k miles). After discussing with Don at ARB USA he confirmed this is how it should be installed in the US. Interesting since i know there are some out there that have the taller spring on the passenger side with no lean.

for reference, my post about all things I tried to eliminate lean.

Builds - Wyoming HE Build

ARB install complete. Man that was quite the project. Worked on it over a few days mostly alone and the instructions left a few details out that took me a while to figure out. Turned out pretty good though I think. Suspension feels better already (having been preloaded for it) so that was nice...

forum.ih8mud.com

If you put the taller one on the driver's side of a US model, then yeah you're entirely backwards from how mine is set up. I'm actually not surprised though, I know of several people with the same Tough Dog kit as me and it seemed like they were maybe 60/40 with the taller spring on the passenger's side in order to make it level. I really cannot explain why, though when given the choice I'd still always start with the taller spring on the side with the gas tank since that's how the trucks come from Toyota.

 

[AnyMal]

my .02. After trying opening KDSS valves multiple times trying different methods to get rid of the lean, nothing worked. As @linuxgod mentioned there is a longer A spring for the drivers side and B for Passenger (according to ARB BP51 Instructions). My Toyota dealer installed as per instructions saying that it is important that the taller spring be on the side of the fuel tanks which is our passenger side (Aussie drivers) so he followed ARB instructions. After having no success getting rid of my lean I swapped the taller A to US drivers side and my rig sits perfectly level now. (2021 with 10k miles). After discussing with Don at ARB USA he confirmed this is how it should be installed in the US. Interesting since i know there are some out there that have the taller spring on the passenger side with no lean.

for reference, my post about all things I tried to eliminate lean.

Builds - Wyoming HE Build

ARB install complete. Man that was quite the project. Worked on it over a few days mostly alone and the instructions left a few details out that took me a while to figure out. Turned out pretty good though I think. Suspension feels better already (having been preloaded for it) so that was nice...

forum.ih8mud.com

I think i figured out what youre saying? LOL I thought you were in Australia for a moment.

ARB being Australian is going to provide an offset spring kit which makes sense for them since the truck can be driven that way.
What I'm saying is that there is no need for any offset spring setup on any LHD truck.
Despite what Toyota or ARB is doing or saying, i don't believe there to be any other major imbalance but gas tank.

All other things being equal:
matching springs, settled and re torqued suspension, KDSS valve balancing, full tank of gas, and 150 lbs in the LHD drivers seat the truck should sit level.

 

[AnyMal]

If you put the taller one on the driver's side of a US model, then yeah you're entirely backwards from how mine is set up. I'm actually not surprised though, I know of several people with the same Tough Dog kit as me and it seemed like they were maybe 60/40 with the taller spring on the passenger's side in order to make it level. I really cannot explain why, though when given the choice I'd still always start with the taller spring on the side with the gas tank since that's how the trucks come from Toyota.

Its probably age, fuel level and cargo area load. I want to get data and consensus on this myself.

 

[residualboulders]

I think i figured out what youre saying? LOL I thought you were in Australia for a moment.

ARB being Australian is going to provide an offset spring kit which makes sense for them since the truck can be driven that way.
What I'm saying is that there is no need for any offset spring setup on any LHD truck.
Despite what Toyota or ARB is doing or saying, i don't believe there to be any other major imbalance but gas tank.

All other things being equal:
matching springs, settled and re torqued suspension, KDSS valve balancing, full tank of gas, and 150 lbs in the LHD drivers seat the truck should sit level.

yeah I get what you're saying. All I know is that after everything I tried it wasn't until I put that taller spring on the drivers side that it fixed my problem. Maybe it has to do with variances in the rear springs strength or spring rate during manufacturing at Tough Dog, Dobinsons, ARB etc.? I'm just stoked I fixed mine, ha ha.

 

[AnyMal]

yeah I get what you're saying. All I know is that after everything I tried it wasn't until I put that taller spring on the drivers side that it fixed my problem. Maybe it has to do with variances in the rear springs strength or spring rate during manufacturing at Tough Dog, Dobinsons, ARB etc.? I'm just stoked I fixed mine, ha ha.

Oh buddy. No one in the universe was more satisfied by leveling their truck than I was! I would have sold it otherwise.
I totally get you.

 

[residualboulders]

Oh buddy. No one in the universe was more satisfied by leveling their truck than I was! I would have sold it otherwise.
I totally get you.

Ha ha, me too. I fought the lean on my 40 for 20 years. In the meantime bought an FJ55 which also had a lean issue. They were old and cheap so I dealt with it (cheap back then, not so much now). I finally sorted those two out last fall and I was so stoked. So you can imagine my dismay when I bought the brand new HE 200, immediately had the dealer install the BP51 and of course when I pick it up it has a 1 1/2" lean. Dealer had no idea how to fix it.