Step 1

Remove the Saddle Clamps and hardware. Turn the 4mm hex bolts counter-clockwise to remove them from the Saddle Clamp Nuts. Set all clamps and hardware aside.

Step 2

Remove the black air cap at the top of the post by turning it counter-clockwise with a 10mm socket, then slowly release the air pressure by depressing the Schrader valve with a lint-free towel covering the valve to prevent any fluid spray.

Step 3

Push Top Cap down and use a seal pick or other small tool to rotate the retaining ring so that the ring gap is at the front of the post. Pull the retaining ring out with your fingers.

Step 4

Thread your FOX shock pump onto the top cap clockwise then pull up to remove the cap from the upper post.

Step 5

Clean your bike work stand clamps and the exterior of the seatpost to prevent damage during clamping. Clamp the seatpost in your workstand, then unthread the Lower Post Collar by turning it counter-clockwise by hand. If too tight to unthread by hand, you may use channel lock type pliers with a shop rag to protect the collar from damage. Remove the o-ring under the collar.

Step 6

Unthread the Bottom Cap counter clockwise to remove it from the lower post.

Step 7

Separate the Upper Post Assembly from the Lower Post. Take note of the position of the ball bearing in the base lug and mark the anti-rotation hole that the ball bearing was found in. This is in case the ball falls out during service.

If you use a Sharpie or other marker to make this mark, take care not to remove the mark as you clean parts throughout the rebuild. A scribed line is also an option for marking the position of the ball bearing.

Remove the keys and index pins.

Step 8

Clamp the Upper Post Assembly in your bike stand. Remove the Pushrod from the bottom of the Shaft. Using a T25 torx to hold the Shaft in place, unthread the Base Lug counter-clockwise from the Shaft using a 10mm wrench.

Step 9

Remove the Lower Bushing followed by the Lower Bushing energizer o-ring, Top Out Washer, and Collar assy.

Step 10

To replace the Dust Wiper use a flat screwdriver with a twisting motion to lift up on the Wiper.  

Step 11

Setting the Collar Assembly against a table, use a pick to remove the retaining ring that sits between the Bushing Carrier and Collar.

Step 12

Clamp the Upper Post in your bike stand (you may need to use a soft jaw vice to hold the head of the Upper Post for this procedure). Use a pair of smooth-jawed parallel pliers (Knipex) to unthread the Bottom Seal Head from the Upper Post. Pour out all oil into your waste oil basin. Push the IFP out through the top using a long Delrin Push Rod or a nonmetallic dowel. Note: IFP color may vary. 

Step 13

Very GENTLY clamp the wrench flats on the Pressure Tube in a soft jaw vice and unthread Bottom Seal head counter-clockwise from the pressure tube with your Knipex smooth-jawed parallel pliers. Over-clamping the pressure tube will bind the threads, making it very difficult to loosen the seal head.

Step 14

Remove the Main Shaft Assembly then remove Bottom Seal Head from Main Shaft. Pour the oil out from Pressure Tube into your wate oil basin. 

Step 15

Unthread the Main Piston using your T25 in the bottom of your Main Shaft and a 10mm wrench at the base of the Main Piston. Remove the o-ring and backup ring from the end of the shaft with a plastic pick.

Step 1

Install a new backup ring and greased o-ring from the kit into the end of the shaft as shown. Thread the new Piston Assembly from the kit onto Main Shaft. Use a 10mm wrench to hold the Piston Assembly while you tighten the shaft clockwise to 40in-lb (4.5Nm) with a T25 Torx driver.

Step 2

Coat the shaft threads and the inside of the sealhead with Slick Honey, then install the new Bottom Seal Head from the kit onto the Main Shaft.

Step 3

Add a thin layer of Slick Honey on the Push Rod then reinstall into the Main Shaft

Step 4

Thread the Open Valve Thumb Screw(PN 398-01-162) to hold the actuator open.

Step 5

Grease the Piston Assembly then reinstall into the Pressure Tube.

Step 6

Thread on Bottom Seal Head and torque to 60in-lb (6.8Nm) with a 24mm socket (for 30.9mm/31.6mm posts) or a 26mm socket (for 34.9mm posts). You must push Shaft into Pressure Tube.

Step 7

Install Upper Bushing Carrier Assembly from kit into your Post Collar. Hold Collar against a flat surface and reinstall your retaining ring.

Step 8

Install new wiper seal/anti-rattle ring assembly from the kit. Use Wiper Install Tool (398-01-162 for 30.9/31.6 or 398-01-164 for 34.9) and use a soft jaw vise to press Wiper Seal into Collar Assembly. The top of the wiper flange must sit flush with the top of the collar.

Step 9

Pack the new wiper with Slick Honey, then reinstall Collar Assembly onto Upper Post, followed by Top Out Washer

Step 10

Install new greased Lower Bushing Energizer O-Ring and new Lower Bushing from kit. Orient Bushing split to side of the post.

Step 11

Reinstall Pressure Tube Assembly into Upper Post and torque to 90in-lb(10.2Nm) with a 24mm socket (for 30.9mm/31.6mm posts) or a 26mm socket (for 34.9mm posts). You can do this on your bike stand or soft jaw vice. 

Step 12

Remove the IFP screw with a 5mm non-ball end hex wrench by unthreading it counter-clockwise. Replace the IFP seals with new greased ones from the kit making sure they are not twisted after installation. Reinstall IFP into Upper Post with screw out. Note IFP color may vary.

Step 13

Install IFP Spacer (398-01-137 for 30.9/31.6 or 398-01-138 for 34.9), followed by Retaining Ring.

Step 14

Install the Fill-Machine adapter(398-01-165) clockwise into the IFP.  Connect the fitting to your vacuum/fill machine filled with FOX 1.5wt. oil (025-03-035). Perform the vacuum and fill cycles. It’s EXTREMELY important that the post is inverted several times while vacuum filling and cycling the shaft.Disconnect the vacuum bleed fitting from the IFP. 

Step 15

Remove the wire retaining ring and IFP spacer. Install the pin into the correct hole of the IFP setting tool for your travel (398-01-134 for 30.9/31.6 or 398-01-135 for 34.9). Insert the castellated feature of the IFP tool into the upper post and rotate to engage with the features of the IFP. Press down until the pin through the IFP tool contacts the topmost part of the upper post. Hold the IFP with the IFP tool while you tighten the bleed screw clockwise with a 5mm hex to 3 in-lb torque.

Step 16

Pour out the excess oil from the IFP chamber, then inject 1.5cc of FLOAT FLUID into the IFP chamber.

Step 17

Replace seal on Top Cap with new greased one from the kit.

Step 18

Reinstall Top Cap into Upper Post. Install retaining ring(orient ring gap to relief at front of post) and charge post up to 325psi. Reinstall Air Valve Cap finger tight using a 10mm socket.

Step 19

Remove Open Valve Thumb Screw of the bottom of the shaft. Hold the Base Lug in place with your 10mm wrench while you tighten the shaft COUNTER-CLOCKWISE into the Base Lug, tightening (counter-clockwise) to 30in-lb (3.4Nm) torque. Reinstall the Push rod after torque.

Step 20

Coat the entire upper post below the collar and the top 2.5" of the inside of the lower post with a thick (clump-level) film of Slick Honey. Install the Index Pins and Travel Adjust Keys.

Step 21

Rotate the base lug so that the ball aligns with the back index pin.

Align the ball bearing with the groove in the inside of the Lower Post that is closest to the laser etching on the back of the Lower Post. Align the back of the upper post (higher of the two saddle mounting tabs) with the laser-etching on the back of the lower post. Slowly feed the Upper Post Assembly into the Lower Post. 

Note: Increased force may be required to install the upper post into the lower post as the lower bushing is energized by the o-ring.

Step 22

Thread the Actuator into the end of the Lower Post. Tighten the Bottom Cap clockwise using its thickest part to 40 in-lb (4.5 Nm) torque.

Step 23

Install the Lower Post Collar, tightening clockwise until hand tight. Reinstall the Lower Post Collar O-ring.

Step 24

Reinstall the Saddle Clamps making sure all arrows face the front of the post. Clean the exterior of your post with Isopropyl alcohol.