King coilover seal and oil service

cozdude

Guy with a Red 2-Door
For the past few months my jeep hasn’t felt like it was riding like it should. The front end felt like it was sagging and leaning to the driver side and the rear was just super squishy and not responding to the bumps in the road right.

I knew I had driven over the recommended mileage that king suggests to do an oil change (15k miles) but being on the east coast I don’t have any local places to have them serviced. That being said it would have cost way to much money to ship them anywhere, pay for the service (avg cost I found was about $125 a shock), then pay for shipping back. So I decided to dive in head first and do the service myself and learn something along the way.


What you need:
King Seal kit 21000-900 (maybe different on shocks compared to coilovers)
King shock oil- 1 gallon
Vice
5/16 Allen Head
1/4 ratchet
3/16 Allen Head
1/16 Allen key
24mm socket
1/2” wrench
Small screw driver or pick
Soft dead blow hammer
Valve steam remover (or the like)




1. Once you remove the coilovers from the jeep place it in a vice with the shock shaft sticking up.
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2. Release the nitrogen from the remote reservoir
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3. Grab your 1/16 Allen key and loosen the stop screw
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4. Loosen the dust cap and slide up the shaft. I used and adjustable wrench and towel to remove since mine were a little stuck.
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5. Next your going to see the seal cap. Push down with both hands to expose the snap ring at the top of the shock body.
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Once exposed use a small screw driver and remove the snap ring
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6. SLOWLY pull the shock shaft out. Oil will go flying if you yank it out really quick!
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7. Dump oil out of shock body and resi into a container.
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8. Place the shock shaft into the vice
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These next few steps are very important! Keep everything in order and remember how it came off!

9. Grab your 24mm socket and 1/2” wrench and remove the nut at the end of the shaft.
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10. Carefully take everything off and lay it out in order! You do not want to loose any valving shims or lose any parts!
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11. Take the dust cap and r&r the seal.
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12. So the same with the seal head.
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There is also a seal in the middle of the head. It is clear and very heard to see. I missed it my first go around
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13. Once the new seals are in the dust cap and the seal head place everything back on the shaft. When putting the nut back on tighten to a little past snug
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-You can now put the shock shaft on the table and place the shock body in the vice.
 

cozdude

Guy with a Red 2-Door
there are seals in the remote resi as well you will need to replace.

14. Take the remote resi in your hand and push on the cap where the steam is to expose another snap ring. Once exposed remove the snap ring and the blue resi Head with a valve steam remover.
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15. Take your dead blow hammer and easily hit the open end of the resi to move it down the tube. At the other end is another snap ring that needs to be removed
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(I forgot to take some pics for this part so please forgive me)

16. Inside the resi there is once last piston that needs to be removed. Get it out however you choose (I used the butt end of a screw driver).

17. Replace the three large seals on the remote resi ends and on the internal floating piston and put back together

Very important next few steps.

18. Once the resi is back together you need to set the depth of the floating piston. Per king the correct piston depth is all the way pushed forward. To do this you will need access to some sort of air pump. (Arb compressor for filling tires will work perfectly). All you need to do is give it a quick shot of compressed air to set the piston. Once you do so DO NOT let the air out of the resi.

19. Once resi is complete you can now add the new oil. Add oil till it is about 1” below the snap ring line in the shock cylinder.
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(Sorry no pics from here out as I needed two hands to do the job)

20.Once you do so tip the shock towards the 90* fitting to bleed the air out of the hose (this will take several minutes)

21.Once all the air is out of the tube to the resi, top off the oil so it is back to about 1” below the snap ring line.

22.you can now insert the shaft. Slowly insert the shaft just far enough so that the valve shims and top out washer (big fat one at bottom of threaded end of shaft) have oil over top of them and that the oil is just above the snap ring line.

23.slide the seal cap down the shaft into the shock body while keeping the shock itself in place. This should push the remaining air out of the shaft and allow the seal head to close the shock up. Push it in as far as you can go.

24.you can now remove the compressed air from the resi. And push the seal head in the rest of the way so you can reinstall the snap ring. Still make sure that the shock shaft is being held up as much as you can while pushing the seal head down.
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25.once snap ring is install you can use the shop air again to make sure the shock is sealed off right and that your snap rings are seated properly.

26. Push the dust cap down, screw it back in, and tighten the Allen bolt with your 1/16th Allen key.
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27. Remove the compressed air again and your all set to have them charged with nitrogen!
 

cozdude

Guy with a Red 2-Door
Now the rear is the same up until one part of doing the seals in the remote resi’s.

You will need a 3/16 allen socket and 1/4” wrench to remove the two bolts at the top of the resi.
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Once the screws are out it will come apart like so
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Note: the seal pictured above does not have a replacement in the seal kit listed. Do not lose it!

Push the oil end cap down to expose yet another snap ring
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Replace all seals and reinstall the resi. Then follow the steps above for bleeding the shock and reinstalling it all.
 

cozdude

Guy with a Red 2-Door
So it’s been two days of me driving the jeep since the seals and oil have been done and I have to say, I can’t believe how much better it rides! The new oil and fresh nitrogen make a world of difference! If you have king shock or coilovers I would deff suggest at least doing new oil every 15k miles your drive.

Please let me know if you guys have any questions! I will be glad to help if I can!
 

Samuelh3

Caught the Bug
You must have read my mind. I was literally at the King HQ last week changing the pressure on my shocks and the guys told me it was time to service my coil overs. Apparently I’ve been pretty hard on them. Thanks for the great write up. Planning on doing this very soon.


Sent from my iPhone using WAYALIFE mobile app
 

WJCO

Meme King
So it’s been two days of me driving the jeep since the seals and oil have been done and I have to say, I can’t believe how much better it rides! The new oil and fresh nitrogen make a world of difference! If you have king shock or coilovers I would deff suggest at least doing new oil every 15k miles your drive.

Please let me know if you guys have any questions! I will be glad to help if I can!

Wow that looks like a lot of work ( a lot of parts organization anyways). That's awesome you took the initiative to do it yourself. How does the oil get so dirty being in a sealed assembly like that?
 

cozdude

Guy with a Red 2-Door
Wow that looks like a lot of work ( a lot of parts organization anyways). That's awesome you took the initiative to do it yourself. How does the oil get so dirty being in a sealed assembly like that?

It’s a little overwhelming on the first once but once your done the next three go super fast. I think it took me 2 hours for the first one then maybe 2-1/2 hours for the next three.

I can only imagine that it’s like trans oil where it gets dirty from heat and wear of the moving parts and just breaks down over time
 

Sessoms14X

Member
Awesome that you took the dive to do this yourself Coz! This is one of the big reason that I won't go coilovers. I'd be way too scared to try this myself. Great write up though.

Sent from my SM-G955U using WAYALIFE mobile app
 

TrailHunter

Hooked
4.5 hrs isn’t bad.... bet you can get it down to 3 next time. 15k seems fast... and I bet more guys would go coilover if it was like 50k for service.... but 15k on a non daily driver is probably every 2 years or less.... thats not too bad. But if daily driven or wheeled every weekend... 15k can come up quick... cool write up [emoji1360]
 

cozdude

Guy with a Red 2-Door
4.5 hrs isn’t bad.... bet you can get it down to 3 next time. 15k seems fast... and I bet more guys would go coilover if it was like 50k for service.... but 15k on a non daily driver is probably every 2 years or less.... thats not too bad. But if daily driven or wheeled every weekend... 15k can come up quick... cool write up [emoji1360]

Thank you.

I guess it depends on how far you drive on a daily. My jeep has been my daily since I got it. Luckily I don’t have a far commute each day. This service was done at about 22k miles since I installed the coilovers almost 3 years ago. Yes I was way overdue but it makes a world of difference doing it. For $150 total to do the oil and seals and have them charged with nitrogen myself it really isn’t that bad.
 

TrailHunter

Hooked
Thank you.

I guess it depends on how far you drive on a daily. My jeep has been my daily since I got it. Luckily I don’t have a far commute each day. This service was done at about 22k miles since I installed the coilovers almost 3 years ago. Yes I was way overdue but it makes a world of difference doing it. For $150 total to do the oil and seals and have them charged with nitrogen myself it really isn’t that bad.

3 years.... thats not bad at all.
 

Ddays

Hooked
So do any of the internal parts besides the seals ever need replacing? How do you know if they ever do.
And I’d imagine the shock rebuild is similar?


Sent from my iThingie
 

cozdude

Guy with a Red 2-Door
So do any of the internal parts besides the seals ever need replacing? How do you know if they ever do.
And I’d imagine the shock rebuild is similar?


Sent from my iThingie

There are two other internal piston wear bands that may need to be replaced at some point (one in the resi and the other in the shock body) but I didn’t get them. Will prob replace them next time around. They looked in good shape and felt good.

I would assume that the shock rebuild will be extremely similar! Only difference would be the part number for the seal kit
 
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