Shock Shim Setup

I feel you but, in the end it's worth if you can figure it out... Tons of money and time up front but now I'm seeing the light..
Our last trip I could go up to 70 on forest road and power line trails. My OME set up I could go around 45 ... Now I can go 50 like I'm driving down the road no problem.....

 

OK, thanks to help here, the Fox 2.5 Factory Series coilovers are re-shimed and gassed up. Tomorrow is install and road test day. Now that I've gone through this process, I like the shock construction better. Hopefully, the new shim set will make a difference in ride. I'm not too worried if there's a couple iterations on this since I got much better at dealing with these the second time.

The shims are now a relatively light compression set with one flutter shim:

1.8 0.008
1.6 0.010
0.8 0.010
1.425 0.010
1.350 0.012
1.1 0.010
0.95 0.010
0.8 0.020

I had watched videos and read about this but still encountered a few challenges along the way. The first shock took probably 3 hrs. The second about one so there is a learning curve.

Compressing the springs was scary. I used an OEM compressor set, greased the screws, and carefully/gradually squeezed with a small impact wrench. The screws bent more than I'd like. For $30, a second set and maybe use three compressors would feel better. Note the "safety" pins didn't fit these springs. The main thing I did different the second time was just compress the springs enough to loosen the height adjusting ring. Then I backed the ring off until the spring cleared the lower seat. Then I left the compressors on the spring and set it aside. This made it easier/faster to reassemble because the spring didn't need to be compressed from full extension. Also, when re-installing the spring, it helped to keep the height ring close to the spring so the lip stayed engaged. The spring had a tendency to push to one side which then made getting the ring to engage difficult. Instead of a clip at the bottom, these shocks had a two part ring fitting held together with a stretchy o-ring. This seems like a pretty stout retention system.



Then, I uncovered this where I was naively expecting a Schrader valve. The top hat bolt was really tight, bits of red loctite were present. I reinstalled that with blue loctite since that's what I had and will keep an eye on this bolt.



Picking the plastic ball out boogered up the allen area and didn't extract the ball easily. So, on the second one, I hand drilled and plucked it out:



This got me to here (boogered version):



OK, now we need to let some nitrogen out. I slowly loosened that allen screw and heard about a puff worth of gas escape. I had the shock tipped up so oil wouldn't gush. I could then move the shock shaft into the body so I figured it was OK to remove that screw. What's behind there is a little rubber pellet. This is a needle type nitrogen valve system. More on that later.

Now that the pressure is gone, you can remove the sweep seal for another surprise. Remember there is a set screw that secures the outer seal on top of this snap. It's awful tight until you loosen that. Anyway, videos showed a light clip holding the piston that easily picked out of the body to remove the piston and shims. Not so on these:



This was a pretty heavy duty snap ring that challenged my feeble ring pliers. I ordered a new plier set after this, I've always struggled to get these out cleanly.

The shim process followed what I expected from videos etc.

The needle nitrogen fill system ended up looking like this. It's WAY overkill for the tiny bit of nitrogen needed. If you're in the Portland/Vancouver area and need some nitrogen, I have a lifetime supply. Maybe I'll fill some tires. But, this nitrogen is important. There's a Bilstein video showing an unpressurized clear shock get all foamy until the nitrogen pressure hits it and the oil clears instantly. BTW, these shocks had red oil in them. This gas pressure keeps the shock oil from foaming up.

After assembling this system, poking the nitrogen in was a non-event. Just set the regulator to 200 psi and poke the needle straight in. Don't bend the needle, I guess they're prone to breaking. I snugged the allen screw up after the poke just for some extra sealing. One disadvantage to the needle fill system is you can't really check the post fill shock pressure with a gauge AFAIK. I did a re-loosen of the allen screw and gas hissed out so some did go in. Then I poked it again. I don't know how many pokes these pellets are good for but probably more than three is risky. If you charged the body with gas before you put the springs back on, you could see the shaft move out and know gas went in.

Another option is to probably call a suspension shop and get $20 worth of nitrogen filling done.



Tomorrow I'll report on the road test.

 

That looks a lot better Should ride much better...
I wound up getting a nitrogen bottle set up also, makes it easy to make adjustments and rebuild when needed.

After doing it a couple times goes much faster. Getting the spring off is the hardest part..

 

Yes, the whole process does get much easier. You learn little tricks to ease the shocks in and out of their tight fit location. Like using a jack under the LBJ to raise the spindle height to allow the top to go in under the upper control arm, tighten the top pretty snug, then work the jack down and align/ease the lower bolt in.

The ride is much improved with the new shim set. The sharp impulse raps are significantly reduced. I was able to drive some of our crap roads and actually think about something else besides getting pounded. Even some washboard was tolerable and I didn't skate over the edge. It's still "firm," but there was only about 50 lbs in the bed. Normal camping load would be at least 500 lbs including a light dirt bike. The sway is still off so swervy actions might get surprising. This setup deserves some evaluation time under different loads, surfaces, and tire pressures.

I'm much happier now that a process is defined and a good baseline has been achieved.

As an added bonus, the truck is very level side/side with 1/4" (2.75 total inches of thread showing) more "preload" on the driver side.

Thanks again for the help!

 

Update... The ride after going quite light on compression shims was still darn stiff. I took a flyer and ordered some 14" long 3" dia King 550 lb/in springs. The Fox springs were 600 lb/in. The King springs fit the Fox 2.5 seats but are somewhat more difficult to fit spring compressors on due to less tube clearance. The new springs finally made a really feel-able difference. I can now feel the front suspension moving. I just got back from 65 miles of semi rough wheeling and am very happy with the result. With the softer springs and sway bar deleted, I'd say there is some additional twisty highway sway, but that's a small price to pay for the off road benefit. This is probably the point where adjustable shocks would come in handy.

Also, after the spring swap, I went from 315 75 16's to 285 75 16s. Somewhat less manly, yes, but now I have much reduced turning radius w/o rubbing on the frame. This is very handy for those multi-point turnaround situations. And parking lots.