The Fox 36 Factory GRIP2 fork stands out for its high-end adjustability and top-tier trail performance. Equipped with a sophisticated damper system, the GRIP2 offers both high-speed and low-speed compression and rebound adjustments. However, like any advanced suspension system, it requires routine maintenance and occasional full rebuilds to maintain optimal performance. This guide offers a detailed, step-by-step process to rebuild the Fox 36 Factory GRIP2, covering all critical components and technical aspects to help you complete the job correctly and confidently.
Tools Required
- 10mm and 6mm hex wrenches
- Torque wrench [paid link] (in Nm)
- Plastic or rubber mallet
- Suspension oil (Fox 5wt Teflon-infused and Fox 20wt Gold)
- Clean workspace and lint-free cloths
- Suspension pump
- Pick set or seal puller
- Oil syringe or measuring cup
- Retaining ring pliers
- Replacement wiper seals and foam rings
- Genuine Fox dust wiper seal kit
- Isopropyl alcohol (99%)
- Grease (e.g., Slickoleum)
Disassembling the Fork
Start by removing the front wheel, brake caliper, and thru-axle. Release all air from the fork’s air spring to prevent pressurized oil from ejecting during disassembly.
Carefully loosen the foot nut bolts on the bottom of the fork legs using a 10mm hex. Do not fully remove them initially—tap gently with a mallet to disengage the internal shaft ends from the lowers. After this, remove the bolts and allow oil to drain into a container. Slide off the lower legs carefully while keeping them level to avoid spillage or damage to the bushings.
Inspect the lower legs and clean them thoroughly with isopropyl alcohol. Remove the foam rings and dust wipers using a seal puller or pick set, taking care not to gouge the casting surfaces.
Inspecting and Replacing Wear Components
The foam rings, dust wipers, and crush washers should be replaced during each rebuild. Inspect the stanchions and bushings for unusual wear or scuffing. If damage is found, consult a professional service technician or consider replacing the lowers entirely.
Install new foam rings and soak them in 20wt Gold oil before installing. Carefully press the new dust wipers into place using a seal driver or appropriately sized socket. Avoid hammering directly on the seals, as uneven force can compromise the fork’s sealing.
Servicing the Air Spring
To access the air spring, remove the top cap with a 6mm hex wrench. Pull the air shaft assembly from the stanchion. Wipe it clean and inspect for wear on the shaft and piston seals. Replace the air piston O-rings and seals if needed.
Lubricate the shaft with a light coating of Slickoleum and reinstall. Torque the top cap to factory specifications, ensuring no cross-threading occurs when threading it into the crown.
Rebuilding the GRIP2 Damper
Unlike open bath dampers, the GRIP2 cartridge is sealed and requires precise servicing. Remove the damper side top cap and pull the cartridge from the stanchion. If performing a full rebuild, follow the damper-specific service manual to disassemble and replace internal shims, O-rings, and seals.
Refill with Fox 5wt Teflon oil using a syringe to ensure precise volume and vacuum bleed to remove any trapped air. Improperly bled dampers can result in cavitation and inconsistent damping performance.
Reinstall the GRIP2 damper cartridge and torque the top cap correctly. Always check for any sign of oil leakage around the seals before proceeding to reassembly.
Reassembling the Fork
Apply a small amount of Slickoleum to the dust wipers and the inner bushing areas. Carefully slide the lowers onto the stanchions, ensuring the damper and air shafts pass cleanly through their respective bushings.
Measure and add the appropriate amount of 20wt Gold bath oil through the open foot nut holes. Insert new crush washers on the foot nut bolts and torque them to spec (commonly 5.1 Nm or as noted by Fox).
After confirming smooth shaft movement, reinstall the brake caliper and front wheel, and torque the axle properly. Inflate the air spring to the rider’s preferred pressure using a suspension pump.
Setting Adjustments After Rebuild
Once reassembled, set the rebound and compression adjusters to a baseline factory tune. Turn each adjuster fully clockwise (closed) and then open them the recommended number of clicks.
For example, begin with 8 clicks out on both high- and low-speed rebound and 10 clicks out on low-speed compression. Fine-tune to rider weight and terrain preferences after a test ride.
Troubleshooting Common Rebuild Issues
If you notice excessive oil leakage post-rebuild, recheck the crush washers and dust wipers for correct seating. A squelchy or inconsistent feel in compression may indicate trapped air in the damper due to an incomplete bleed.
A harsh ride or lack of small bump sensitivity usually points to dry or poorly lubricated seals. Always ensure foam rings are fully saturated and grease is applied liberally around seal contact points.
Custom Tuning and Performance Optimization
Advanced riders often fine-tune shim stacks inside the GRIP2 damper for custom rebound and compression behavior. While this requires in-depth suspension knowledge, Fox offers tuning kits and documentation for this purpose.
Additionally, experimenting with different bath oils or volume spacers in the air spring side can optimize bottom-out resistance or plushness. Always make changes one at a time and test thoroughly.
Comparing the GRIP2 with Other Fork Dampers
The GRIP2 stands out for its fully independent high- and low-speed compression and rebound adjustability. In comparison, the FIT4 damper offers a lighter-weight option with fewer settings, better suited for XC and trail riders.
For enduro-focused riders, the GRIP2 provides superior traction tuning capabilities. However, it comes with increased weight and servicing complexity, which may not be ideal for casual users.
Compatibility with Drivetrain and Other Components
The Fox 36 Factory GRIP2 is designed for modern 29-inch and 27.5-inch enduro bikes with boost spacing. It is compatible with both 15x110mm thru-axles and 180–203mm post-mount disc brakes.
While unrelated to drivetrain performance directly, fork sag and front-end compliance do influence shifting under heavy load. Ensure proper setup to minimize drivetrain inefficiencies due to suspension dive or pogoing.
Conclusion
Rebuilding the 36 Factory GRIP2 fork ensures your suspension delivers maximum performance and longevity. With its intricate damper and air spring system, precise care and adherence to service intervals are key. Always use genuine parts, work in a clean environment, and follow torque specifications closely to maintain factory-grade functionality.