KDSS piston stroke?

Question - does anybody know what is stroke of front KDSS piston?
Essentially how much clearance should I have between end of KDSS piston and skid place?
Thank you!

 

I don't. But, when I was testing my skids for clearance, I drove up a set of ramps. One on the driver's rear tire, and one on the passenger front.

 

Yup, that's backup plan - measure what clearance is in still position, then measure on ramps, and write down difference.

 

I don’t know either, but have a look at .

 

I'll be putzing around at home today. Maybe I can get a measurement.

 

Oh, sorry for misunderstanding, I meant I'll do measurements by myself, I have ramps

 

I didn't think you wanted me to measure for you. I was just curious, so I figured I'd check while I was screwing around this morning.

Anyway, I don't know if I got the piston fully extended, but it dropped about 1-1/8" when I drove up the ramps (front passenger and driver rear).

Here's the before:



After:

 

from the looks of things you can definitely benefit from some billet clamps. cheap insurance.

https://drkdss.com/products/kdss-front-sway-bar-billet-clamps-pair

 

i have read that the kdss ram has some clearance issues with a trd oem/style skid plate. some have notched it under the ram and called it good while others are staunch about the trd and even the oem plate not having proper clearance for the ram when fully extended.

the ram itself will retain enough fluid pressure when the valves are open to keep it from completely topping/bottoming out in normal slow speeds movement cases. at the same rate i’ve seen the front ram beat the crap out of the stock stamped steel skid during high speed whoops though the use is abnormal since the valves are kept open electronically.

 

Greater minds than ours have already given this matter their consideration. See the link in my post above.

 

the thread provided addresses clearance for the sway bar and maybe one blurb about the ram not touching the skid. i’d hardly call that definitive for the OP’s question about the kdss ram’s dimensions.

 

Yes sir you are right. It doesn’t answer OP’s specific question. But it does address the point of his question. It provides many photos of skid plates that have been successfully modified to accommodate KDSS, as well as a template that one can use to trim the skid plate so that it doesn’t interfere with the KDSS, which is the whole point of OP’s question.

 

the point of his question is clearance for the ram. the information provided primarily addresses sway bar clearance, which assuming the attached photo is his, is already addressed.

chopping the sides off of a pro skid does not make more clearance for the ram. the nature of the pro plates design leaves little clearance for the ram as shown in the photo. notching the plate where the ram can land has been done and in some cases with success. but harder driven 4rs will flex that ram straight into the plate.

 

Oh gosh, you are so kind! Thank you so much!
So I measured my skid plate (aftermarket) and I have only 5/8" available for the piston.
So time for a jigsaw to work!
I will consider 1-1/2" as a safe clearance.

P.S. I do not have TRD skid plate, I have this one.
Photo from original post is for youtube as example.

 

Are you running a KDSS spacer on the passenger side? Those can cause the piston to fully extend, and create more issues with the front skid plate. After I removed my front spacer there is now plenty of room on the drivers side.

 

Good point! And, a good reason to keep lift modest on a KDSS 4runner.

But, don't those spacers come in pairs? I wouldn't think anyone should ever run a spacer on one side without the other.

 

The sway bars cycle/relax differently because IFS vs. Solid Axle.

Only the solid mount is spaced since the ram levels itself based on independent tension from the sway bar ends on the LCAs. Technically the front spacer is supposed to restore proper tension/bushing angles at the ends if the truck is lifted, by bringing the sway bar down. i'd correct at the end link with adapters before i'd use a front spacer, simply because of skid plate clearance issues us kdss people have to keep an eye on.

Not a tension issue but a cycling/position problem for the rear. Lifting the rear brings the sway bar axle mounts down but they are "hinged" so the tension problem doesn't exist like IFS. The spacers drop the sway bar so there's less vertical angle when the axle cycles down which in turn helps control fore and aft motion of the axle. The abnormal axle cycling also causes less clearance between the sway bar mounts and pan hard, which is why the generic axle cycle test is to lift the rear until full droop hits, and see if the sway bar ram/body mounts touch the pan hard.

 

This sounds all wrong to me. The sway bar should sit level. Putting a spacer on only one side of it is going to make the sway bar always want to sit at an angle. No good. It doesn't matter if it's IFS or solid axle

 

The Treaty Oak spacers are sold as two (both rears) or three (rears and passenger front). I recommend running the spacers on the rear only. In front, I would go with either the adjustable bushing brackets (to clock the bushing angles to match the lift), or the brackets with the sway bar end adapters (if running extended travel shocks).

 

I'm not asking for a recommendation. What I'm saying is that putting only one space around the front defeats the purpose of adding the spacers. Their whole purpose should be to allow for extended droop, but running only one on the front does not allow for that.

 

i understand your perception. the fixed mount is the pivot point for the ends of the bar that fights for equilibrium/level. the kdss ram is dynamic at rest or >12mph which allows for that equal tension or level sway bar to occur.

 

I know how KDSS works.

What I'm pointing out is that, by lowering the fixed mounting point without lowering the dynamic mounting point, you're going to lose droop under articulation. You might gain a little on the passenger side, but you're losing some on the driver's side. That doesn't seem beneficial to me.

 

my intention wasn’t a kdss lesson but was made surrounding statements of the sway bar not sitting level.

your question about articulation is a fair one and really begs the question of the true stroke length of the ram and what spacing it does. maybe there’s risk of damage if the ram bottoms out with a spacer? i think that’s only part of the story of the asymmetric front spacer but i won’t continue with further thoughts.

obviously practically testing and studying technical measurements is a good start to finding answers. maybe one of these weekends i’ll test what the end adapters net. unfortunately i don’t have the clearance for a spacer haha

 

Yeah, it makes sense that the piston can compensate for the added length of the spacer, allowing the sway bar to sit level under regular driving conditions. I didn't think about that initially.

But, with a spacer only on one side, it seems like you are going to sacrifice droop on one side or the other under articulation. It seems like it would make more sense to me to lower both sides equally, if at all.

 

With one spacer, the piston extends to sit level. It has to - it is connected to both lower control arms. This pushes it down to normally ride near the skid plate. When you flex the driver's side, it extends even further down, potentially hitting the skid or over-extending the piston. Issues with piston and skid are why I removed my front spacer.

Adding a second spacer on the piston side would seem to protect the piston from over-extending, but I would be concerned with the piston being over-compressed when the drivers wheel is stuffed to the fender.

Leaving the front stock is a decent approach - just keep an eye on the clamps and bushings.

 

It has been brought to my attention that my clamps could use some attention, lol. Not sure if I will go for the Dr. KDSS clamps, or try to fashion something on my own.

 

it’s a shame that toyota deemed a rubber strap glue and a tin strap around it acceptable to keep the sway bar in place. at any rate i’m sure anything you can come up with would be a lot better.

 

In case anyone is still interested, I found that the ram has about 3.5" of total stroke in my testing, 1.75" up and 1.75" down. Therefor, as the 4R sits with all tires on level ground, you should have up to 2" of clearance between the bottom of the RAM and a skid plate.