Loose at high speeds

[TheInfamousDrew]

I recently picked up another truck and noticed this too. It 37" tires, 2.5" RPG collars and a 3" block in the back. If I recall correctly, there are two things that can help. Upgrading the front springs to either Eibach or Geiser. Also adding Roadmaster Active Suspension.

It can definitely be scary when getting on the interstate and the truck begins to sway at 75mph.

 

[JCSRaptor]

This is absolutely a real phenomena. I too have experienced it. 2019 SCREW and above 90mph the truck shimmies. it feels like the truck becomes weightless and wobbles side to side for a sec then comes back under control. Very odd, uncomfortable feeling. I do not remember it happening with KO2s. But I did not run it above 90 all that much. I have new recon grapplers now and have definitely experienced this issue. I am running low pressure for recons 37psi on all four. I have DSC active suspension control and that did not settle this behavior down. But I have to say it does improve handling in all other scenarios. I will try increasing tire pressure as others have claimed it’s easy to do and test. I’ll report back

 

[wheelman55]

2018 Raptor stock (no lift, after market springs, etc), stock KO2’s with ceramic balance beads. Air pressure varies, but always 4 psi less in the rear vs front.

Routinely drive at governed max (108ish) on local test track for 20+ miles continuous. No shimmy, no wander, no shakes.

Make sure to have “lane control” switched off. That alone will pinball you between the lines.

Be safe. Local deer population has no concept of speed

 

[TwizzleStix]

Yeah, just another reference, my 2018 (tuned of course) will run 140mph (on paved surface) with zero issues. The tires don’t like it and make lots of noise because they’re S rated, but no sway, vibration, weaving, etc. I’ve lowered the rear by ~1.5” with rear spring shackle, but stock everything else.

I’m on second set of OEM C-rated KO2 BFG.

 

[JCSRaptor]

2018 Raptor stock (no lift, after market springs, etc), stock KO2’s with ceramic balance beads. Air pressure varies, but always 4 psi less in the rear vs front.

Routinely drive at governed max (108ish) on local test track for 20+ miles continuous. No shimmy, no wander, no shakes.

Make sure to have “lane control” switched off. That alone will pinball you between the lines.

Be safe. Local deer population has no concept of speed

You know maybe i did have lane assist on. certainly not intentional but i did notice it when breaking from one lane to the next. hmmmm, ill have to check to see if it is as simple as that. Would be nice if that is all it was...

 

[wheelman55]

Yep. The lane control can feel floaty.

 

[JAWSRaptor]

how many miles are on the truck? wheel bearing issue?

 

[JCSRaptor]

42kmi on truck. No don’t think it’s a bearing issue. In all others cases truck is solid. I went back to see if lane control was on and it was not enabled. Not sure if it deactivated when I shut off the engine. I usually wait till late in the evening when traffic is minimal to run speed tests on the highway. J am going to inflate the Nittos now o. The truck to oem specifications and see if that helps. The Nittos are a 10 or 12 ply tire and are much firmer than the KO2. So I dropped cold pressure to 35psi. Will try 38 cold and then 42 cold. And see. If that’s not it then I need to investigate for camber caster. Something is a little off.

 

[slow_raptor]

Mine has the "floating" feel above 80mph I'm running 37" Mickey Thompsons M/T. I do blame mine to shocks since I'm at 97k miles... I need to replace my shocks or rebuild them.

 

[ruey220]

not sure, but why would you put 20" wheels on an off road truck? serious question

can the bbk fit on 18s? I was told I need 20s for my 8 pistons to fit.