Clearancing Sway Bar for Large Tires (1 Viewer)

[TeCKis300]

Looking to get this discussion going as to strategies to fit larger and full fat meats.

I recently modded the LX570 sway bar to allow full steering lock on 37x12.5s. For context, I'm running +28 offset and on AHC high (about 4" total lift creating down-angle on the LCAs which pulls the tire towards the frame) and full steering lock, the tires will rub on the sway.

Hoping this could be expanded to the LC KDSS system to enable them to likewise fit larger and wider meats. This takes some resources to modify, but it could be a way to work around the pesky interference that's been holding back LCs.

I've done a few wheeling trips and am cautiously optimistic that metal fatigue on the spring bar is going to be okay. I can't find enough pictures of the KDSS system to say there's enough clearance to make it work, but being that the mod would be to a lever, rather than the spring bar, eliminates that complexity.

Strategy is to cut/grind away where the interference is, while welding back enough structure elsewhere.

End product. The LX sway uses 8mm walled tubing. I cut away about 1/2" of protruding bar where the tire witness marks were. Welded back material to fill the hole in the tube. Added a horizontal plate to the back to replace the structure while avoiding geometry that would create stress risers. Interestingly, the passenger side seems to have more interference than the driver side.

Chopping with an angle grinder

Fitting and welding back metal to close hole

 

[TeCKis300]

I'm really curious as to the KDSS lever and what could be done there with a similar grinding and reinforcement strategy. Could not find great pictures showing the layout and geometry and hoping others have pictures to share? Heck, I'm interested enough that I might offer to do some hacking and welding on an extra KDSS bar just to explore.

 

[TeCKis300]

There is some previous art here and the Russians seem to have done this to a greater degree

I use a totally different method for the KDSS arm. The plates that lower and move the whole arm forward cause way more issues than they solve and cause binding. I keep the center hole where it is and remove 23mm from the front of the arm and add it to the rear, effectively moving the bends 23mm forward. Can fit a 35" tyre with ZERO scrub.

 

[kcjaz]

I'm really curious as to the KDSS lever and what could be done there with a similar grinding and reinforcement strategy. Could not find great pictures showing the layout and geometry and hoping others have pictures to share? Heck, I'm interested enough that I might offer to do some hacking and welding on an extra KDSS bar just to explore.

I’ve had this same idea. For 35s not much grinding would be needed (depends on a lot of other details though). I’ve kicked this around with our welding/material guy at work and it is 100% theoretically possible to grind out clearance on one side and add back member cross section with weld on the other side to maintain strength. The challenge is finding out exactly what the material is that the KDSS link is made from and it’s OEM heat treatment. It would also be good to know what the loads the level arm is subjected too. I’ve also called a custom shop to have a modified bar made but it was prohibitively expensive unless you were willing to buy 100 or more units.

 

[clrussell]

I’ve had this same idea. For 35s not much grinding would be needed (depends on a lot of other details though). I’ve kicked this around with our welding/material guy at work and it is 100% theoretically possible to grind out clearance on one side and add back member cross section with weld on the other side to maintain strength. The challenge is finding out exactly what the material is that the KDSS link is made from and it’s OEM heat treatment. It would also be good to know what the loads the level arm is subjected too. I’ve also called a custom shop to have a modified bar made but it was prohibitively expensive unless you were willing to buy 100 or more units.

I wonder how hard it would be to get a 100 on a group buy?

 

[clrussell]

@TeCKis300

Here are pics from my 2008 LC.

Mine polishes the KDSS infer certain conditions

Tires are 315-70r17 on 17x9 “0” offset (35-12.5)

Pictures are at full lock

 

[clrussell]

From above. It’s not touching just the angle.

 

[clrussell]

I think if/ when I go to 37s with my “0” offset wheels I will get a KDSS relocate kit and move the links outside the control arms. Effectively pushing my sway bar forward 1” which in theory should put me basically back to where I am now on 35s

 

[bloc]

Per a past conversation with someone with experience modding and wheeling a bunch of 200s (taco2cruiser I think, apologies if it was someone else) even if you can make the KDSS arm work on an equipped cruiser, eventually you run into problems with the tire tearing up the cylinder boot, with obvious consequences for cylinder life. This will all seem fine in the driveway but it's when things get really flexed up that the issues arise.

Not saying this all is a bad idea, just that there will eventually be other considerations for the LCs

 

[CanadianRockyCruiser]

@TeCKis300 is never afraid to bust out the grinder and welder!

 

[Boston Mangler]

I was going to replace my KDSS arm as part of my full refresh because it has several likely worn to hell bushings in it.

Bushing not available separately

But new it’s $820+

Just an FYI before ya start some chop chop

 

[turbo8]

I was going to replace my KDSS arm as part of my full refresh because it has several likely worn to hell bushings in it.

Bushing not available separately

But new it’s $820+

Just an FYI before ya start some chop chop

View attachment 3765072

Febest makes replacement bushings. I've used their bushings in my rear control arms. No issues after 5 years.

 

[TeCKis300]

Great stuff and I was hoping to get the juices flowing.

From @clrussell pics, it looks wholly possible to grind the KDSS bar face that's interfering and add support to the back side.

As this bar doesn't have spring steel treatment complexity, it would just be a matter of adding enough structure back to this cast part, depending on how much material was removed. I don't think filler compatibility is as critical. Adding material back would look like sistering a metal plate to the back side, and possibly a cap above and below.

For larger tires, I think it's necessary to pair this with a KDSS relocation kit. As @bloc pointed out, 37s can probably get into the bellows and the relocation helps push the cylinder.

 

[Boston Mangler]

Febest makes replacement bushings. I've used their bushings in my rear control arms. No issues after 5 years.

View attachment 3765214

Ooh. Thank you

 

[bloc]

For larger tires, I think it's necessary to pair this with a KDSS relocation kit. As @bloc pointed out, 37s can probably get into the bellows and the relocation helps push the cylinder.

For more context the conversation was about 34s or more specifically 285/75R17s. We didn't talk about relo kits but my gut is that's not enough movement to clear 37s. Though that is such a large jump other mods will be made, and that could change the calculus.

Might be best to get him into the conversation if possible.. I just checked and it was @Taco2Cruiser