SERVICE PROCEDURES
2021-2025 40mm Mud Guard Installation
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: Never install the FOX 40 Mud Guard without first adjusting the “top of crown” to “top of upper tube” position to a maximum of 132 mm (A). The FOX 40 fork with the FOX 40 Mud Guard “top of the crown” to “top of the upper tube” position MUST BE EXACTLY 132 mm or SEVERE INJURY OR DEATH may result.
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.
Step 1
Measure the distance from the top of the Lower Crown to the top of the Upper Tubes. This dimension must be set to 132mm if using the FOX 40 Mud Guard.
Step 2
If the distance from the top of the Lower Crown to the top of the Upper Tubes is not 132mm you must change the position of the Upper Tubes in the Crowns. Loosen all 6 bolts in the front of the Upper and Lower Crowns by turning them counter-clockwise with a 5mm hex wrench.
Step 3
Slide the Upper Tubes up or down in the Crowns until the measurement from the top of the Lower Crown to the top of the Upper Tubes is 132mm.
Step 4
Tighten all 6 bolts on the front of both Crowns clockwise to 65 in-lb (7.3 Nm) torque with a 5mm hex wrench.
Step 5
Position the front of the fork so it is facing down. Unthread the Pressure Release Button Assembly counter-clockwise from the lower leg with a 13mm socket. If you have Pressure Release Plugs unthread them counter-clockwise with a 5mm hex wrench.
Step 6
Remove the Spacer from the Pressure Release Button or Plug Assemblies.
Step 7
Position the Mud Guard in place so the large holes align with Pressure Release ports and the small holes align with the threaded holes in the back of the lower leg brace. Reinstall the Pressure Release Buttons or Plugs by threading them clockwise. Tighten to 45 in-lb (5.0 Nm) torque.
Step 8
Thread the provided screws through the small holes of the Mud Guard into lower leg brace. Tighten clockwise to 4.5 in-lb (0.5 Nm) torque with a either a 2mm or 2.5mm hex wrench depending on the screws provided.
