KDSS 2" Lean

[05Rrunner]

It's so awesome to watch devoted loyal customers argue for a product they have no technical knowledge of or background on at all , and Toyota loves blind devotion ! The system has it's limits I can't tell you how I know those limits but what I'm telling you is true. to those of you out there thinking about purchasing KDSS or have it good for me . I make no more or less money by trying to help you enthusiasts by giving the inside track . I'll be here on the forums 10 years from now advising people on how to repair and remove that antiquated system and most of you other guys will be long gone.

 

[STX4Runner]

It's so awesome to watch devoted loyal customers argue for a product they have no technical knowledge of or background on at all , and Toyota loves blind devotion ! The system has it's limits I can't tell you how I know those limits but what I'm telling you is true. to those of you out there thinking about purchasing KDSS or have it good for me . I make no more or less money by trying to help you enthusiasts by giving the inside track . I'll be here on the forums 10 years from now advising people on how to repair and remove that antiquated system and most of you other guys will be long gone.

"...blind devotion..."? [MENTION=66316]1engineer[/MENTION] sold his KDSS 4Runner for an SR5!

"...no technical knowledge..."? He's an f'ing engineer that designs hydraulic systems.

I'll admit, I have KDSS, but am not defending the system, just attacking the ignorance in your post. Why can't you tell us how you know what the limits of the system are? Why can't you tell us how heavy it is? It's only a thicker sway bar, hydraulic lines, accumulators and two pistons. How heavy is that?

I agree with [MENTION=66300]Intruder[/MENTION]. Why can't a KDSS thread on this forum not turn into a shit show? It's a fine system that works as intended.

 

[dahorst]

It's so awesome to watch devoted loyal customers argue for a product they have no technical knowledge of or background on at all , and Toyota loves blind devotion ! The system has it's limits I can't tell you how I know those limits but what I'm telling you is true. to those of you out there thinking about purchasing KDSS or have it good for me . I make no more or less money by trying to help you enthusiasts by giving the inside track . I'll be here on the forums 10 years from now advising people on how to repair and remove that antiquated system and most of you other guys will be long gone.

The plot thickens. Are you affiliated with Toyota in any way? Personal question I know. So before we all agree to disagree, would you all be ok with the following:

1. Under very extreme conditions off road (high speed, high temp, rough terrain) kdss may pose issues after prolonged use.
2. Under 'normal' offroad conditions (ones that most people on this site experience) kdss actually improves performance.
3. Kdss is an additional system that, like all other systems, may complicate diagnosis of issues

 

[mo_mo]

It's so awesome to watch devoted loyal customers argue for a product they have no technical knowledge of or background on at all , and Toyota loves blind devotion ! The system has it's limits I can't tell you how I know those limits but what I'm telling you is true. to those of you out there thinking about purchasing KDSS or have it good for me . I make no more or less money by trying to help you enthusiasts by giving the inside track . I'll be here on the forums 10 years from now advising people on how to repair and remove that antiquated system and most of you other guys will be long gone.

So far you've shown that you have zero understanding of how KDSS works, so forgive us for not blindly following you. Perhaps you'll let OP get back to resolving his suspension problemo.

 

[Intruder]

I'll be here on the forums 10 years from now advising people on how to repair and remove that antiquated system and most of you other guys will be long gone.

Yup, because we'll have gotten tired of trolls like you and left the forum. You'll still be here because the internet is the only place where you can feel important by pretending you know more than you do. Have fun!

 

[Belcher]

My bone stock '14 trail is leaning a hair over 3/4"...no mods.

WTF

Chris

 

[1engineer]

It's so awesome to watch devoted loyal customers argue for a product they have no technical knowledge of or background on at all , and Toyota loves blind devotion ! The system has it's limits I can't tell you how I know those limits but what I'm telling you is true. to those of you out there thinking about purchasing KDSS or have it good for me . I make no more or less money by trying to help you enthusiasts by giving the inside track . I'll be here on the forums 10 years from now advising people on how to repair and remove that antiquated system and most of you other guys will be long gone.

Either bring it or STFU about this subject. I gave my qualifications, how about yours?

 

[K9trainer]

I will explain the heat issue with KDSS. The system operates using hydraulic fluid transfer, pressure and valves. Very similar to a shock . the valves open and close to increase and decrease resistance. When the KDSS system is cycled repeatedly quickly like running through the desert the fluid heats up when it heats up to a certain point The oil starts to foam those tiny bubbles slip past the valves you lose resistance the KDSS becomes ineffective like a blown out shock and The 4runner starts to act like it has no sway bars. Not a good situation. This is where reservoir shocks came from. Also this problem was amplified with the small lift in the TRD pro and is amplified more when you lift and increase wheel travel as it increases the stroke it increases the heat problem.

Another reason this system is a street cruiser system is you lose ground clearance in all the wrong places right in the front and right off the tale of the housing in the rear the system is vulnerable off-road. And very heavy.
A KDSS equipped vehicle has lower ground clearance than a standard 4runner how does that make sense for off-roading, it doesn't because it's not designed for off road.

The system is extremely heavy , outdated and will be replaced with a more modern version using electronics, again designed for the street crowd.

The KDSS System had its place it was a nice addition to the Lexus , as the years go on people will be tearing off these KDSS systems like previous generations removed rear air lift , xreas suspensions. it's just too complicated , limits your ability to modify and wait till you need replacement parts ! Oh man

So what your saying is, you didn't get a 4Runner with KDSS, and now you opinion is fact.

 

[Honu*]

ooohhhh you are giving me a awesome smile as I laugh this morning though thanks for the humor hahahahaahhha

I will explain the heat issue with KDSS. The system operates using hydraulic fluid transfer, pressure and valves. Very similar to a shock . the valves open and close to increase and decrease resistance. When the KDSS system is cycled repeatedly quickly like running through the desert the fluid heats up when it heats up to a certain point The oil starts to foam those tiny bubbles slip past the valves you lose resistance the KDSS becomes ineffective like a blown out shock and The 4runner starts to act like it has no sway bars. Not a good situation. This is where reservoir shocks came from. Also this problem was amplified with the small lift in the TRD pro and is amplified more when you lift and increase wheel travel as it increases the stroke it increases the heat problem.

Another reason this system is a street cruiser system is you lose ground clearance in all the wrong places right in the front and right off the tale of the housing in the rear the system is vulnerable off-road. And very heavy.
A KDSS equipped vehicle has lower ground clearance than a standard 4runner how does that make sense for off-roading, it doesn't because it's not designed for off road.

The system is extremely heavy , outdated and will be replaced with a more modern version using electronics, again designed for the street crowd.

The KDSS System had its place it was a nice addition to the Lexus , as the years go on people will be tearing off these KDSS systems like previous generations removed rear air lift , xreas suspensions. it's just too complicated , limits your ability to modify and wait till you need replacement parts ! Oh man

 

[Jetboy]

The plot thickens. Are you affiliated with Toyota in any way? Personal question I know. So before we all agree to disagree, would you all be ok with the following:

1. Under very extreme conditions off road (high speed, high temp, rough terrain) kdss may pose issues after prolonged use.
2. Under 'normal' offroad conditions (ones that most people on this site experience) kdss actually improves performance.
3. Kdss is an additional system that, like all other systems, may complicate diagnosis of issues

This pretty well sums it up.

As far as #1 - the Toyota Factory race team's KDSS 4runner has about 100k on it now and hasn't had issues with its KDSS. Every Land Cruiser for the last 10 years has it. Every Gx460 has it. The failure rate seems quite low considering the population of vehicles with the system and relatively low number of issues we're seeing.


It's clearly not ideal for extra long travel suspensions. Neither is IFS. At each level of offroad design there are various demands and different balancing of needs. One of the huge benefits of KDSS is body control - which is pretty important when you have 500lbs of gear on your roof rack. For expedition use KDSS does a great job. OTOH if you're wanting to run pritchet canyon - you probably don't want KDSS. There are certain tasks it works well for, and some it doesn't.

Whenever I get around to redoing my FJ40 suspension to 4 links at each end, I'm going to add a home brew KDSS sway bar system and see how it does with a very long travel setup. Once you reach a point of travel, body control becomes more important than more flex. My FJ40 already ramps about 1200. I don't need more flex as much as I need stability in very twisty sections and on the highway. I think KDSS or similar type system has a viable role in high travel suspension as well, but not a factory system like the one on the 4runner. Just like the stock IFS and rear links - it's not designed nor capable of such things.

It's also very clear 05Runner hasn't got a clue how KDSS works. If he did, he'd know that it is locked out above 12mph so there's no measurable fluid heating up in desert runs. It's not like this is news to the rest of us, but apparently he hasn't even looked at a 4runner owners manual.

 

[dahorst]

Last night I pulled out the radflo coilover assembly, which was pretty easy by the way. I tested the movement of the upper/lower control arms and as suspected there were no issues, thus narrowing down the issue. I put the spring compressors on and began disassembling the shock. I got to the point where my coil is removed and the nitrogen and hydraulic oil is drained. I couldn't get the top 'head' off which is required to remove the cylinder/shaft. I plan on calling radflo today for detailed instructions. The hydraulic oil was almost black in color, not yet sure if this is normal. Compressing the shock with no spring on it was 'choppy' and felt like it was catching or something. Right now I'm leaning toward a sticky valve. I plan on doing the rebuild myself. Only thing I'm concerned about is the nitrogen refill...i'm hoping somebody in town is willing to help. If not, I suppose I'll build my own kit.

The last time I spoke with radflo they told me that they do not use synthetic oil. I figure this is a big issue for me since -40degree weather in the winter here is not uncommon...definitely can explain my harsh ride in the winter and perhaps a busted valve? Maybe [MENTION=66316]1engineer[/MENTION] will chime in. Anyhow, more to come. I might start a new thread on the rebuild process since I can't find anything on the web specific to the radflos.

 

[1engineer]

I'll be happy to help but let's see what Radflo sends you first. Hydraulic fluid coloring means nothing unless you know what color it was to start. Does it smell slightly burnt?

Synthetic fluid in a shock would be nice but due to a shock's duty cycle (continuous extension/retraction) standard fluid will heat up to nominal operating condition in just a few minutes. Also there are additive packages available for petroleum based fluids that are perfect for shock applications. The nitrogen precharge should be pretty easy to do but you have to know what the precharge pressure is and be able to charge precisely to that pressure. Let us know.

 

[Intruder]

You could always ask Radflo about different valving for your shocks. The valving you have is the Overland Warehouse custom design, but maybe they have different valving options for the 5th gen that might work better for you. Either way, consider rebuilding all four shocks at once or at least both the fronts. The rebuild process should be very similar to other emulsion shocks (non-resi) like the ones Fox and Icon sell.

 

[dahorst]

Ok, so after speaking with RADFLO today and getting them to send me the rebuild instructions, I was able to disassemble the entire shock with ease. Upon initial inspection everything looked ok.....until....

Take a look at the 'valves'. There are a couple, what I call, 'bypass holes' drilled between adjacent holes. One of them was completely botched during manufacture; they even left a broken drill bit tip in the hole! unbelievable.

Anyhow, I'll talk to RADFLO again tomorrow, but do you guys know if there are meant to be 1, 2 or 3 of those bypass holes?

The fluid has definitely changed colors. Per RADFLO, their fluid has always been blue in color.

Also, while my friend and I were working my friend had an epiphany. He remembered that when we released the nitrogen, hydraulic fluid came out of the release/fill port (actually all that fluid you see in the bottle). The way I understand it, the floating piston is meant to seal the hydraulic fluid from the nitrogen and there should be no intermixing between the two?

If I'm assuming correctly my thought is this: The botched manufacture of the valve perhaps over pressured the shock causing the hydraulic fluid to bypass the seals into the nitrogen chamber thus 'jamming' it up. What do you think?

 

[nb rob]

Great pics and feedback. And excellent work with the shocks. I hope Radflo stands by their product and makes the replacement parts available to you ASAP.

 

[nb rob]

I'll bet you want to pull the passenger side out now huh?

 

[dahorst]

I'll bet you want to pull the passenger side out now huh?

Yes but it will be dependant on a few factors. 1. How easy this rebuild ends up being. 2. How the newly rebuilt shocks feels in comparison to the passenger side shock. 3. Whether I feel like it or not.

 

[nb rob]

I think you'll be surprised. The hard work is done.
I've had shocks filled with nitrogen at a local snowmobile/4 wheeler/toy shop.
I'm sure there's one in Ft. McMurray

I'd press radflo for a washer stack specific to your vehicle,
What the hell right? I really hope they come through for you.

 

[dahorst]

I think you'll be surprised. The hard work is done.
I've had shocks filled with nitrogen at a local snowmobile/4 wheeler/toy shop.
I'm sure there's one in Ft. McMurray

I'd press radflo for a washer stack specific to your vehicle,
What the hell right? I really hope they come through for you.

From what I understand, since these are the overland warehouse trim coilovers, they were specifically designed for modified 5th Gen 4runners.

 

[Lexusbstrdchild]

Good find, sorry you had to go through all that work. Good write up tho. All the nonsense about KDSS...makes it funny it had nothing to do with it.