Fox float QS3 shock rebuild

[Octanee]

Has anybody rebuilt one, got a video or manual on it? i tried to google and came up dry.

Today my Left front shock decided to puke the oil out with out any warning, was dry and now I have a springy shock lol. I'm trying to hopefully find either a rebuild kit canada side ASAP or a complete shock then will rebuild that one after.... I'm unsure the "fox" part number for the shock as well...

I tried a forum search and came up dry on this, I suppose the shocks must be pretty reliable all in all then!

 

[boondocker97]

I rebuilt one off of a brand new 2018 that was leaking air. Had a course hair or fiber that got in with the main air seal on assembly from the factory. Fox makes two different spanner tools to unscrew the seal heads off of the float 3 shocks. You'll need the deeper reaching one of the two. We tried to make one with some hardened pins and an aluminum block, but it was too deep of a reach and snapped the pins. Get the Fox tool. You'll also need the float air sleeve bullet tool. You need these things since the the air sleeve is longer than the shock body and won't slide down far enough to get past the seal head.

 

[Octanee]

I rebuilt one off of a brand new 2018 that was leaking air. Had a course hair or fiber that got in with the main air seal on assembly from the factory. Fox makes two different spanner tools to unscrew the seal heads off of the float 3 shocks. You'll need the deeper reaching one of the two. We tried to make one with some hardened pins and an aluminum block, but it was too deep of a reach and snapped the pins. Get the Fox tool. You'll also need the float air sleeve bullet tool. You need these things since the the air sleeve is longer than the shock body and won't slide down far enough to get past the seal head.

I did get mine apart and maybe i got the seal head off because it was loosened? I used 2 screw drivers and a pry bar to spin it out, Low and behold some damaged threads and my tube is mushroomed and egg shaped. One place I called said it likely loosened off and caused the distortion.... Being the holidays people arent at their shops and so I've gotta wait I guess to see about getting it fixed.

 

[Old & slow]

There is good rebuild info in the service manual. You can find one on line at Country Cat. Just go to their home page scroll to the bottom technical info. Shock rebuilding is usually at the back of the manual.

 

[Octanee]

There is good rebuild info in the service manual. You can find one on line at Country Cat. Just go to their home page scroll to the bottom technical info. Shock rebuilding is usually at the back of the manual.

I just looked and there indeed is A shock rebuild process but its not right for these fox float 3's/Qs3 shocks.

I ended up getting lucky and local dealer had a damaged shock but the tube the piston threads into was fine, Swapped it all over and should be good to go... Guess I'll find out next weekend If I get out how it is.

 

[Goinboardin]

I rebuilt one off of a brand new 2018 that was leaking air. Had a course hair or fiber that got in with the main air seal on assembly from the factory. Fox makes two different spanner tools to unscrew the seal heads off of the float 3 shocks. You'll need the deeper reaching one of the two. We tried to make one with some hardened pins and an aluminum block, but it was too deep of a reach and snapped the pins. Get the Fox tool. You'll also need the float air sleeve bullet tool. You need these things since the the air sleeve is longer than the shock body and won't slide down far enough to get past the seal head.

I was wondering if the air chamber cap had to come off the shock rod to fit the seal head tool on there with how long the air sleeve is. Good to know that's not the case with the right tool.

For the bullet tool, do you have a link to one? I'm pretty green to shock servicing but tired of sending & waiting for services, going to start doing this myself. Between my sled, my friends', my bikes, and truck shocks, pretty easy to justify gearing up for it.

Just for information's sake, Carver Performance has rebuild kits for these shocks (PN 11-22000), and the IFP depth is 1.45". Hygear Suspension has kits as well (PN 29-03-109R). On my '18 mountain cat, the left clutch side shock part number is 3703-763 is and the right shock is part number 3703-762.

 

[boondocker97]

Here's the float bullet tool: https://carverperformance.com/bullet-tool-float-air-sleeve-installation

use that to get the air sleeve slid on the shock, then put the rod and seal head down inside the sleeve and screw it into the shock body.

 

[Goinboardin]

Shipping delays and good snow, lead me to make my own seal head tool and improvise a syringe needle filling setup. Got the oil changed in all 4 QS3 shocks and the reservoirs pressurized. Pretty simple when it comes down to it.
0. Clamp shock in vise by the eyelet.
1. Release all air and nitrogen charge.
2. Unthread air can from end cap.
3. Depress reservoir cap to expose snap ring, remove snap ring with pick.
4. Use two screw drivers to pry reservoir cap up. Work out out completely.
5. 1/8" hex key removes bleed screw from IFP.
6. Use smaller hex key to remove set screw from seal head, note there is a small ball bearing under it, do not lose it!
7. Use seal head tool (slotted socket with two 3/16" diameter pins) to remove seal head from shock body. It's tight! Lefty losey.
8. Lift shock shaft out of the shock body. Rotating can help free it.
9. With a very firm grip with needle nose pliers grab the IFP and pull it out. Rotating can help.
10. Dump oil from shock body.
10.a. You can, but don't strictly need to, pull the air can off the shock body. I did to clean, but without the bullet tool it can be tricky to reinstall this (seal catches the shock body edge).
11. Clean and inspect everything. Replace parts that are questionable.
12. Reinstall air can. I used a little Slick Honey.
13. Pour oil into reservoir side, and main side.
14. Reinstall IFP to a depth of 1.45".
15. Carefully reinstall the shock rod. The wear strips tend to be hard to keep in place, a bent pick was helpful to gently guide them as they slid into the shock body. Once in place, tighten the seal head back into the shock body.
16. You want only oil between the bottom of the seal head and the IFP. I kept oil above both of them and slowly cycled the shock with the bleeders out. Oil will slowly accumulate above the IFP due to gravity, I used a syringe to move it above the seal head as needed. Once confident as much air as possible is out, reinstall both bleed plugs, and don't forget the little ball for the seal head.
17. Pour excess oil from the shock. No need to have oil in the reservoir or the air chamber.
18. Reinstall the reservoir cap and snap ring. Make certain it is fully seated.
19. Recharge the reservoir to 150 psi, ideally with nitrogen. I simply used air (shock pump and syringe needle), but I'll be back in these shocks soon when parts & tools show up.
20. Thread the air can back into the end cap.
21. Fill air chamber to desired pressure.
22. Reinstall on snowmobile.

This isn't a by the book way to do it but it made sense to me. Shocks feel 10 better with fresh oil and charge.

 

[Octanee]

Shipping delays and good snow, lead me to make my own seal head tool and improvise a syringe needle filling setup. Got the oil changed in all 4 QS3 shocks and the reservoirs pressurized. Pretty simple when it comes down to it.
0. Clamp shock in vise by the eyelet.
1. Release all air and nitrogen charge.
2. Unthread air can from end cap.
3. Depress reservoir cap to expose snap ring, remove snap ring with pick.
4. Use two screw drivers to pry reservoir cap up. Work out out completely.
5. 1/8" hex key removes bleed screw from IFP.
6. Use smaller hex key to remove set screw from seal head, note there is a small ball bearing under it, do not lose it!
7. Use seal head tool (slotted socket with two 3/16" diameter pins) to remove seal head from shock body. It's tight! Lefty losey.
8. Lift shock shaft out of the shock body. Rotating can help free it.
9. With a very firm grip with needle nose pliers grab the IFP and pull it out. Rotating can help.
10. Dump oil from shock body.
10.a. You can, but don't strictly need to, pull the air can off the shock body. I did to clean, but without the bullet tool it can be tricky to reinstall this (seal catches the shock body edge).
11. Clean and inspect everything. Replace parts that are questionable.
12. Reinstall air can. I used a little Slick Honey.
13. Pour oil into reservoir side, and main side.
14. Reinstall IFP to a depth of 1.45".
15. Carefully reinstall the shock rod. The wear strips tend to be hard to keep in place, a bent pick was helpful to gently guide them as they slid into the shock body. Once in place, tighten the seal head back into the shock body.
16. You want only oil between the bottom of the seal head and the IFP. I kept oil above both of them and slowly cycled the shock with the bleeders out. Oil will slowly accumulate above the IFP due to gravity, I used a syringe to move it above the seal head as needed. Once confident as much air as possible is out, reinstall both bleed plugs, and don't forget the little ball for the seal head.
17. Pour excess oil from the shock. No need to have oil in the reservoir or the air chamber.
18. Reinstall the reservoir cap and snap ring. Make certain it is fully seated.
19. Recharge the reservoir to 150 psi, ideally with nitrogen. I simply used air (shock pump and syringe needle), but I'll be back in these shocks soon when parts & tools show up.
20. Thread the air can back into the end cap.
21. Fill air chamber to desired pressure.
22. Reinstall on snowmobile.

This isn't a by the book way to do it but it made sense to me. Shocks feel 10 better with fresh oil and charge.

Great detailed write up! Will be a ton of help to others as it seems like a lot of work but it's not, the tool however to remove that threaded seal head is a must! I didn't know the nitrogen side piston depth based on a spec but I know the concept or idea behind why it's there, oils gotta go somewhere when the shock gets compressed as that rod inside there displaces the oil! so I ended up getting the air bled out of the oil then took the bleeder out of the ifp?/nitrogen side piston and bottomed it out with shock extended then pulled it up a 1/4" or so, working great so far.

Also I had no issues getting the air sleeve back on the shock body with out the tool, I used a O-ring pick to pull that dirt seal out and worked it on the body, it went on smooth with no issues

 

[Goinboardin]

Here's a few pictures that can help people see what they're getting into.