SERVICE PROCEDURES
2018-2019 Trek Thru Shaft Shock Rebuild
Required Parts
- 803-01-157 Seal Kit: Trek Thru Shaft (TSS), Spring and Damper Rebuild
Required Tools
- 398-00-614 Tooling: 2015 Trek RG Valve Stack Transfer Tool
- 398-00-748 Service tooling: Trek Thru Shaft IFP Bleed Screw torque tool
- 398-00-749 Service tooling: Trek Thru Shaft IFP removal tool
- 398-00-951 Tooling: Torque Fixture, 54mm Trunnion Eyelet, Tall
- 803-00-208 or 803-00-805 Kit: Clamp, Shaft and Body, 2005 DHX or Kit: Shaft Clamps, Shocks, CTD 9mm, 3/8in, 1/2in, 5/8in
Sections
WARNING: Always wear safety glasses and protective gloves during service to prevent potential injury. Failure to wear protective equipment during service may lead to SERIOUS INJURY OR DEATH.
WARNING: FOX products should be serviced by a trained 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.
WARNING: FOX suspension products contain pressurized nitrogen, air, oil, or all 3. Suspension misuse can cause property damage, SERIOUS INJURY OR DEATH. DO NOT puncture, incinerate or crush any portion of a FOX suspension product. DO NOT attempt to disassemble any portion of a FOX suspension product, unless expressly instructed to do so by the applicable FOX technical documentation, and then ONLY while strictly adhering to all FOX instructions and warnings in that instance.
WARNING: Modification, improper service, or use of aftermarket replacement parts with FOX forks and shocks may cause the product to malfunction, resulting in SERIOUS INJURY OR DEATH. DO NOT modify any part of a fork or shock, including the fork brace (lower leg cross brace), crown, steerer, upper and lower leg tubes, or internal parts, except as instructed herein. Any unauthorized modification may void the warranty, and may cause failure or the fork or shock, resulting in SERIOUS INJURY OR DEATH.
Disassembly
Step 3
Gently clamp the eyelet in your soft-jawed vise so the mounting bolt areas are the only portions of the eyelet contacting the vise. Remove the black air cap and thread on our shock pump. Slowly release all air from the main air chamber with your pump. Remove the pump. Verify that all air has been released by depressing the Schrader valve with a lint-free towel covering the valve to prevent any oil spray.
Step 6
Clamp the Slave Shaft in your shaft clamps (PN: 803-00-208 or 803-00-805). Slowly unthread the End Cap counter-clockwise with a 10mm socket while holding downward pressure to prevent the IFP spring from popping up and out. Lift it up to remove. Replace the o-ring on the end cap with a new greased once from the kit. Set the IFP spring aside.
Step 7
Remove the shock from the shaft clamps and fully extend the damper by pulling the body away from the eyelet. Position the shock in your soft-jawed vise with the body facing up and the wrench flats of the bearing housing clamped securely. Make sure that no portion of the shock is contacting the vise beneath the jaws.
Step 13
Insert a 2mm hex wrench through the IFP bleed screw torque tool and into the IFP bleed screw. Hold the IFP bleed screw torque tool stationary while you unthread the IFP bleed screw counter-clockwise. Remove the IFP bleed screw torque tool and the bleed screw. Replace the o-ring on the bleed screw with a new greased one from the kit.
NOTE: The following steps show removal and replacement of the adjuster knobs and cam. You do not need to remove the adjuster knobs and cam to replace seals within the shock. Removal of the adjuster knobs and cam is only needed to clean and lubricate these parts and can be skipped if no grit or resistance is felt when making adjustments.
Step 27
Unthread counter-clockwise and remove the set screw from the top of the eyelet with a 1.5mm hex wrench. This will allow for the removal of the adjuster knobs and cam. Make sure not to lose the rebound detent ball and spring which may stick to the back of the rebound knob or remain in the small hole in the eyelet just above the bore for the adjusters and cam.
Step 28
Clean the adjuster knobs and cam then lubricate them with waterproof grease such as Sta-Lube SL3125 from CRC Industries. Affix the detent ball to the back side of the rebound knob or to the detent spring in the small hole in the eyelet above the bore for the adjusters and cam with a small amount of grease. Insert the adjuster knobs and cam making sure to capture the detent ball. Hold the adjusters in place as you reinstall the 1.5mm set screw, tightening clockwise until the screw contacts the cam, then back it out 1/4 turn.
Reassembly
Step 16
Invert the slave shaft and position it onto the IFP bleed screw torque tool. Slowly press the slave shaft down onto the IFP bleed screw torque tool until approximately 1.5" (~38mm) of the tool is still visible. Keep in mind that oil will be pushed through the filter disc and out of the top of the slave shaft.
Step 21
Rest the oil filled body with slave shaft against your workbench or the top of your vise jaws as shown. This will prevent the slave shaft from being pushed out of the body as the piston assembly displaces oil within the body. Slowly insert the valving assembly into the oil-filled body, then thread the bearing assembly clockwise to the body while watching for clean bubble-free oil coming out through the threads at the bottom of the bearing assembly.
Step 28
Insert the IFP bleed screw into the shaft and begin threading it clockwise into the IFP with your 2mm hex wrench. Remove the hex wrench and insert the IFP bleed screw torque tool engaging its hex feature with the hex of the IFP. Insert your 2mm hex wrench through the IFP bleed screw torque tool engaging the hex of the bleed screw. Hold the IFP bleed screw torque tool stationary while you tighten the IFP bleed screw clockwise until hand tight.
Step 32
Install a new travel indicator o-ring from the kit onto the body. Slide the clevis over the slave shaft, then begin threading it clockwise onto the shock body. Carefully clamp the flats of the Clevis in your soft-jawed vise. Tighten to 180 in-lb with your 21mm cone wrench or thinned crows foot.