Truck unsettled, rocks side to side over bumps - King 2.5 level kit

[Poolmonkey]

Seals and oil get wear over time along with loss of nitrogen. Race/prerunner shocks (Fox, Kings, ADS, Icon, Swayaways, etc) are a maintenace item. One could say they never had issues with thier shocks over numerous miles on them, but I guarantee that there is a diffrence in function/ride from new or rebuilt to a non rebuilt with numerous miles on them.
There are videos out there how to rebuild or call King and get a shop near you they may recommend if you don’t know.

They are toys….fun to play with in the field but if a guy doesn’t think they are fun to play with in the garage, best served by something else imo.
The more they are “worked”, the sooner they need attention. Tough to really work them on a 3500, the springs won’t allow it.

 

[Wilder]

Stopping the leaks will not solve your issue. The pressure in the shock has very little to do with the dampening. You have lost dampening because your shocks are worn out. IF there is any oil left in them I bet it is a silvery flaky mess and I can guarantee your piston wear bands are completely worn out and causing damage to the shock body.

As far as rebuilding them yourself, that is fairly easy with the proper supplies. The shocks are a little bit more complicated than a hydraulic ram like you would find on a wood splitter. There are a ton of mom and pop shops on the west coast that get you set up with rebuild parts. Kartek, McKenzies, Shock seals.com, and call King directly. These places will help get you what you need and provide as much support as they can. Also racedezert.com has an awesome forum with members very willing to help. Obviously, I don't know you or your skillset but I would consider them easy to do as long as you're detail oriented and extremely clean.

To be clear I also did a test by pressurizing the shocks and hitting some local bumps at a high speed before all the air leaks out, having the air in the shocks seems to largely resolve the poor handling characteristics. I'm sure it doesn't make them "good as new" but having air in the cylinder obviously does something important

 

[jupp0r]

You can mail the shocks in to be rebuilt. shockservice.com is a reputable shop but there are numerous others. Put your old shocks on (if they have the right length) in the meantime.

Rebuilding them looks easy enough that I will go that route. Here's a video:

 

[Wilder]

I ended up replacing the single seal that is under the reservoir caps at the back of the shock, where they were leaking. At the suggestion of Don Thuren - they don't yet need a rebuild. When opening the reservoir up, there was no signs of damage or corrosion on the inside, and no oil had slipped past the floating piston seal. There was corrosion on the outside of the cap seal, near the retaining ring. When reassembling, I packed this gap with some grease in an attempt to keep dirt and salt out, in hopes that it doesn't deteriorate the seal again. Considering these shocks sit upside down on the truck, and water can pool on top of the reservoir cap- If you run these shocks in a salty environment, I would honestly consider packing the gap with grease as well.



Since replacing the cap seals, they hold pressure and the driving dynamics of the truck are great again.

 

[phatboy64]

Good to see that it was an easy and cheap fix....

 

[jsalbre]

I ended up replacing the single seal that is under the reservoir caps at the back of the shock, where they were leaking. At the suggestion of Don Thuren - they don't yet need a rebuild. When opening the reservoir up, there was no signs of damage or corrosion on the inside, and no oil had slipped past the floating piston seal. There was corrosion on the outside of the cap seal, near the retaining ring. When reassembling, I packed this gap with some grease in an attempt to keep dirt and salt out, in hopes that it doesn't deteriorate the seal again. Considering these shocks sit upside down on the truck, and water can pool on top of the reservoir cap- If you run these shocks in a salty environment, I would honestly consider packing the gap with grease as well.

View attachment 64086

Since replacing the cap seals, they hold pressure and the driving dynamics of the truck are great again.

I wonder if you could find a rubber cap of some kind that would fit over that.

 

[Wilder]

I wonder if you could find a rubber cap of some kind that would fit over that.

I have a bunch of fernco rubber caps for plumbing, I'll check. Might bet lucky

 

[Wilder]

None of the fernco caps I have fit, I'll keep looking for something.

I did come across this today, great illustration of what that air pressure in the reservoir does for the shock

Superbike Services 44 on Instagram: "Anyone want to guess where I have been all week..."

53K likes, 290 comments - superbikeservices44 on October 18, 2023: "Anyone want to guess where I have been all week..."

www.instagram.com

 

[Zuber]

No its not unless thats a new term for the automotive industry

Just do a search for 'lateral head toss'. Plenty of SAE (Society of Automotive Engineers) papers on it.

To fix it is a compromise between shock stiffness and sway bar stiffness.