2013-2016 FIT Terralogic Cartridge Rebuild
- 803-00-503 Service Set: Seal Kit, 2011 32 80-100 TerraLogic Cartridge
- 803-00-546 Service Set: Seal Kit, 2011 32 120 TerraLogic Cartridge
- 803-00-547 Service Set: Seal Kit, 2011 32 130 TerraLogic Cartridge
- 803-00-548 Service Set: Seal Kit, 2011 32 140 TerraLogic Cartridge
- 803-00-549 Service Set: Seal Kit, 2011 32 150 TerraLogic Cartridge
- 398-00-371 Tooling: Sealhead To Shaft Bullet, 10mm
- 398-00-379 Tooling: 2011 Terralogic, Sealhead Bladder Ring Removal
- 398-00-681 2002-017 32 Damper-side and ALL 32-34-36-40 Spring-side Removal Tool
- 398-00-702 Tooling: Fork Topcap Socket, 26mm, 3/8 Drive
- 803-00-084 Kit: Shaft Clamps, FORX, Set #1 (32mm Forx)
- 803-00-147 Kit: Shaft Clamps, FORX, Set #2
- 803-00-650 Service Kit: FIT TerraLogic Hand Bleeder
This service procedure guides you through the rebuild of a FIT Terralogic damper cartridge. For additional information and complete assembly drawings please visit the parts list page for your specific fork at: All Parts Lists »
FIT Terralogic damper Inertia Valve parts must be kept extremely clean during service for proper function.
Improperly cleaning Terralogic damper parts can cause damage. Cleaning only with isopropyl alcohol can leave a sticky oil residue that can lead to improper function of the Inertia Valve.
FOX recommends using an aqueous solution (Mirachem 500 ») and a sonic cleaner or heated parts washer.
Always thoroughly dry cleaned Inertia Valve parts with oil-free and water-free compressed air. Do not dry Inertia Valve parts with cloth or paper towels.
Inertia Valve service should only be done on a clean metal or plastic work surface that will not contaminate parts.
WARNING: FOX products should be serviced by a qualified bicycle service technician, in accordance with FOX specifications. If you have any doubt whether or not you can properly service your FOX product, then DO NOT attempt it. Improperly serviced products can fail, causing the rider to lose control resulting in SERIOUS INJURY OR DEATH.
Use a 2 mm hex to remove the blue threshold adjust knob after turning it all the way counter-clockwise. Free the cartridge from the lower assembly with a 10mm socket wrench and the Fox 32mm damper removal tool (PN 398-00-601). Drain the oil into a waste oil basin.
Turn the red rebound knob all the way out (counter-clockwise), then fully extend the damper. Clamp the damper by the Inertia Valve Housing in the shaft clamps (PN 803-00-147) and remove the red bleed screw with a 1.5mm hex wrench.
Use a 12 mm wrench to remove the inertia valve assembly. It is critical to keep the Inertia Valve assembly as clean as possible as contamination can lead to improper function. Set the Inertia Valve assembly aside in a clean container.
Invert the cartridge over your waste oil basin and drain the oil. Cycle the shaft only 2-3 inches (50-75mm).
Unseat the upper bladder ring retaining ring, taking care not to scratch the shaft. Remove the ring only after sliding it up to the topcap to prevent scratching a critical point on the shaft that needs to pass through the sealhead.
Slip the Terralogic Bladder Ring Removal Tool around the shaft, seating its internal step against the top of the upper bladder ring. Compress the shaft until the topcap is resting on top of the Bladder Ring Removal Tool. Place the open end of the Inertia Valve housing on a rag to cushion it against your workbench, and use your 6-point chamfer-less 26mm socket to protect the topcap. Strike the topcap socket with your mallet to push the tool against the bladder ring, dislodging it.
Use a 24mm wrench on the wrench flats of the lower bladder ring and a 23mm wrench on the wrench flats of the coupler tube, to remove the lower bladder ring from the tube as shown.
Slide the upper and lower bladder ring towards the middle of the bladder, to expose the seal head wrench flats. Use a 23mm wrench on the wrench flats of the IV housing and an 18mm cone wrench on the wrench flats of the seal head to unthread the sealhead from the cartridge body.
Separate the shaft assembly from the cartridge body and remove the bladder with bladder rings. Separate the bladder rings from the bladder.
Clamp the cartridge body in your shaft clamps and remove the Inertia Valve housing with a 23mm cone wrench.
Rebuilding the Shaft Assmebly
Thoroughly clean your shaft clamps and the part to be clamped with isopropyl alcohol to allow for the lowest vise clamping force possible that will let you unthread the topcap assembly. Slide the sealhead up to the topcap and clamp the shaft as shown to remove the topcap assembly with your 6-point chamfer-less 26mm socket.
Install the 10mm bullet tool (PN 398-00-371) into the shaft end, then coat the tapered portion with a thin film of Slick Honey. Install the new sealhead as shown, then remove the bullet tool.
Install a new o-ring onto the rebound needle and coat with a thin film of Slick Honey. Install the rebound needle and spring into the shaft followed by the rebound tube (which is not directional).
Apply a drop of red Loctite 262 onto the topcap shaft threads. Install the topcap and torque to 25 in-lb (2.8 Nm).
Rebuilding the Inertia Valve Assembly
Complete rebuilding of the Inertia Valve Assembly may not be required for all FIT Terralogic damper cartridge services. If rebuilding the Inertia Valve Assembly, replace all o-rings as you go.
Use a 12mm wrench on the dongle to brace against the work surface as you loosen the check shim bolt with a 10mm wrench. Lay the parts out in assembly sequence on a clean work surface.
Use a 12mm wrench on the dongle and a thinner 12mm cone wrench on the timer pocket to loosen and dismantle the inertia valve assembly. Use a 5mm hex on the inside of the shaft to remove it. Lay all the parts out in assembly sequence.
Use a 12mm cone wrench on the timer pocket and a 12mm wrench on the base stud to unthread and separate the two assemblies.
Thread the timer pocket to the base stud. Use a 12mm cone wrench and 12mm crows foot on your torque wrench to tighten these assemblies together to 110 in-lb (12.4 Nm) torque.
Install the valve shims in their original order on the dongle, then thread the dongle to the shaft. Tighten using a 5mm hex inside the shaft and a 12mm wrench on the dongle to 50 in-lb (5.7 Nm) torque.
Install the Inertia Valve onto the shaft followed by the spring and timer pocket assembly. Thread together until hand-tight, then verify that the Inertia Valve slides smoothly on the shaft.
After verifying that the Inertia Valve moves smoothly on the shaft, tighten the assembly with a 12mm cone wrench on the timer pocket and a 12mm crows foot on the dongle to 50 in-lb (5.7 Nm).
Place the compression check spring and shim onto the check shim bolt then loosely thread into the dongle, holding the shim against the check shim bolt as you thread it in. Use a pick tool to gently lift the check shim to test for proper free play. With a 12mm cone wrench on the timer pocket and a 10mm socket on the check shim bolt, tighten to 50 in-lb (5.7 Nm) torque.
Install the upper and lower bladder rings onto the new bladder with their beveled ends oriented towards each other as shown.
Thread the cartridge body into the Inertia Valve housing until finger-tight. Grease the inside and outside ends of the bladder with Slick Honey, then install onto the cartridge body so the threaded lower bladder ring is oriented toward the Inertia Valve housing.
Tighten the lower bladder ring to the coupler with a 23mm and 24mm wrench. As the lower bladder ring will rotate around the bladder end, it is normal for there to be some resistance while threading. Torque to 75 in-lb (8.5 Nm).
Insert the shaft assembly into the cartridge body, keeping the distance between the piston assembly and the sealhead within 3 inches (75mm). Thread in the sealhead. Use a 23mm wrench on the Inertia Valve housing wrench flats and an 18mm cone wrench on the sealhead to torque the assembly to 75 in-lb (8.5 Nm).
Slide the upper bladder ring towards the sealhead, seating it fully aroung the sealhead so the groove is exposed for the retaining ring. Slip the retaining ring onto the damper shaft just under the topcap, then slide it down to the sealhead and install.
Fully extend and invert the cartridge assembly, then gently clamp it into the vise. Pour in FOX 10wt. red oil into the Inertia Valve housing until approximately 2 inches (~50mm) from the top.
Slowly and gently, cycle the shaft in and out approximately 3 inches (~75mm) as you repeatedly squeeze the bladder to free any trapped air. After compressing the shaft and squeezing the bladder, do not release your squeeze or extend the shaft until any air bubbles visible in the oil have reached the surface. This prevents any air from re-entering the cartridge.
Once satisfied that all trapped air has been freed from the cartridge and bladder, prefill the ports in the compression bulkhead with FOX 10wt. red oil before slowly inserting the Inertia Valve assembly into the Inertia Valve housing. Some oil will be displaced during this step. Thread in and tighten to 110 in-lb (12.4 Nm) torque.
Prefill the FIT Terralogic hand bleeder with some FOX 10wt. red oil being careful not to aerate the oil. Thread the bleed adapter into the bleed hole in the base stud.
Holding the syringe in one hand, and holding the fully extended damper (removed from the clamps) in the other, slowly draw the syringe plunger out and hold with your thumb, as you slowly cycle the damper in. This action creates a vacuum which visibly draws the air out of the oil, which floats upwards and into the syringe. Hold in this position (vacuum applied with the syringe, damper shaft all the way in) long enough to visibly vacate all air bubbles.
Release the vacuum in the syringe, then slowly cycle the damper shaft back out. Invert the cartridge into its normal upright position with the rebound knob on top, and gently shake it up and down to activate the Inertia Valve.
Repeat this step until no additional air bubbles can be seen when oil is cycled into the syringe.
With the cartridge inverted so the bleed port is at the top, fully extend the damper and push the syringe plunger in slightly to make sure that the cartridge and bladder are completely full. Clamp the cartridge in the shaft clamps and remove the bleed tool. Install the red bleed screw with a 1.5mm hex wrench tightening to ~3 in-lb (0.3 Nm).
Install the blue threshold knob and test the cartridge for full functionality before continuing with the reassembly. Do not strike the blue threshold knob on anything as you test the cartridge.
Invert the fork and fill with 30cc FOX 20 wt. Gold bath oil in each leg. FOX 20wt. Gold oil should only be used with compatible 32mm dust wipers found in kit: 803-00-878.
Install the bottom nuts with new crush washers, tightening to 50 in-lb (5.7 Nm) torque. Install the blue threshold knob with a 2 mm hex, making sure the set screw correctly settles into its indentation on the threshold adjuster; tighten to 11 in-lb (1.2 Nm) torque.
Additional information regarding updating from 10wt. Green oil to the new 20wt. Gold oil can be found at: http://www.ridefox.com/help.php?m=bike&id=452 »