King Preload Adjustment Experiences

When I installed my King RR Extended Length 600lb/in coil-overs about 1 year ago, I left the preload as they came (about 1/2"). My hub to fender measurements were 21.5" driver and 22.5 passenger. I figured I had some room to play with, so I decided I would add another 1/2" to the driver side and 1/4" to the passenger side.

This web page suggested that I not exceed 21" from top hat to lower shock bolt.

https://accutuneoffroad.com/oem-front-coilover-shock-setup

This measurement is a bit challenging to do alone, but I was able to hang the tape measure off the lip of upper shock mount which is I think is within 1/8" of the top of the top hat. The driver side measured 20.5" and the passenger side 21". I thought this was odd since I was no where near the 2.5" of lift suggested as the max in the accutune article.

I decided to ignore that recommendation and added 5 turns on the driver side using tool from King with the bend. I had just barely enough room around the remote reservoir attachment to make it work. It was actually easier than I expected.

https://www.summitracing.com/parts/kss-25308-100

Measurements after adding 5 turns to the drivers side are 23.5" driver and 24" passenger. This is more than I wanted and I didn't expect the passenger side to change that much. I now have about 1-1.5” of preload on the driver side and 1/2" on the passenger side. The large difference bothers me, but might not be a big issue. I'm going to drive it around a bit before I decide whether to decrease the preload. I have noticed zero difference on the street but need to find some rough terrain to be get a better feel.

Do people generally run the same preload on each side or different preload in an attempt to level the truck side to side?

 

Very common to have different amounts of preload on the front coilovers to compensate for the "taco lean".

Are you saying your coilover measurements are at 23.5" and 24"?

 

No the center of hub to fender flare. I didn’t remeasure the top of hat to lower bolt on the coilover.

 

I took two turns out (about 2/5") of the driver side and now my hub-to-fender measurements are 23" and 23.5" (2-2.5" over stock). It was super easy and I'm happier now.

Now I have to consider if I want to get it aligned. I should still have plenty of caster as I had 4*, but my camber might be off. I'm not sure how much 1.5" of extra lift affects camber.

I also found this newer accutune article on preload that was useful.

https://accutuneoffroad.com/preload-adjustments-on-oem-fit-coilovers/

This one makes no mention of 2.5" being the recommended maximum lift which aligns better with the recommended max shock length at ride height of 21" for the king extended length shocks. 21" is only about 1" of lift on my truck.

I understand the reasoning behind the recommended 3" of down travel, but I have found that a majority of my wheeling has been slow crawls, so I favor clearance over high speed comfort, contact, and control. I might have bought the wrong coil-overs, but time will tell.

 

I didn’t ask my question well. I’m familiar with “taco lean” and that is why I was going to add uneven preload. I was not expecting that adding preload to the drivers side would raise the passenger side so much and still not level it out and also concerned about 2-3 to 1 asymmetry in preload. I am curious about others experiences.

 

Getting ready for summer off-roading season, I remeasured my hub to fender today and it was less than the last time I measured in December.

December/2021 FL: 23”
May/2022 FL: 22.5”

I was a bit surprised by this and decided to readjust the preload.

I sprayed a bunch of lube on the preload threads, measured everything, jacked the front up using the jack point on the TRD skid plate, loosened the lock screw, and torqued the sleeve using the tool from King.

It took a lot more force to turn it than last time. And then I got one turn in and it wouldn’t budge anymore. I tried fiddling with the lock screw and twisting the sleeve back and forth, but it wouldn’t go past 1 turn.

My 2 theories are that 1) the visible whitish corrosion on the threads (I live in the rust belt) was causing extra friction or 2) I damaged the threads. Thoughts anyone?

I gave up, set the truck back on the ground, and remeasured my hub to fender. It was .5” higher on both sides. On a whim, I drove it around the block taking care to drive over some curbs and remeasured. It was back to 22.5” on each side. Wtf? My only theory is binding in the suspension bushings. Could this be the “settling” people often mention?

In any case, I may or may not make an appointment with a shop that has a spring compressor to adjust my preload. I’m not sure .5-1” of added height is worth the trouble though.

 

Depending on how I park, mine can have like a 1.5" lean to one side or not lol. Also my truck stock sat at 20.5" stock, so technically running about 1.5" of lift on my truck with Foxs/600lb/lots of weight.

Im guessing you damaged or skipped a thread, saw it happen on a guys truck who tried adjusting 700lbers without a spring compressor. My foxs I can adjust without a compressor, but pretty tough as I have a couple inches of preload.

 

Little late to the party but... mine got stuck and I ended up making an oval out of one of the holes.

Sprayed a ton of WD40 and some anti seize lube, reclamped then unclamped a few times and it finally backed off. I choked up on a few threads to get to the "seized area", put some anti seize on the area. Put the preload back in and everythings all good again.

I'm no expert but think ya just gotta lube it and play with it

 

Careful! Blindness may result. Giggity.