Servicing the DHX2 Trunnion [paid link] rear shock can greatly extend its lifespan and improve your bike’s performance. Whether you are dealing with wear and tear or simply looking to keep the shock in optimal working condition, this detailed guide will walk you through the process of servicing the DHX2 rear shock without needing a mechanic.
Tools Required
- Fox DHX2 Service Kit
- 3mm, 5mm, and 8mm hex wrenches
- Torque wrench [paid link]
- Shock pump
- Fox-specific oils (e.g., Float Fluid)
- Isopropyl alcohol
- Clean rags
- Needle-nose pliers
- Teflon tape
- Safety gloves
- Small brush
- C-clip removal tool
- O-ring pick tool
- Silicone grease
Understanding the DHX2 Trunnion Rear Shock
The DHX2 Trunnion [paid link] rear shock is a highly regarded coil shock that provides excellent performance for aggressive riding styles. Its advanced damping system, combined with a trunnion mount, makes it a popular choice for mountain bikers who require durable suspension for demanding trails. Regular maintenance ensures that the shock functions optimally, reducing fatigue and improving overall ride quality.
Step-by-Step Guide for Servicing the DHX2 Trunnion Rear Shock
1. Preparing the Shock for Service
Before starting the service, remove the shock from your bike. Begin by using your hex wrenches to carefully detach the shock from its mounting points. Set the shock on a clean surface and make sure you have a stable workspace with adequate lighting.
2. Remove the Coil Spring
To remove the coil spring, first, use the 5mm hex wrench to unscrew the preload adjuster. Once loosened, you can carefully slide the spring off the shock body. Be sure to handle the coil spring with care, as it is under tension.
3. Disassemble the Shock
Now, it’s time to disassemble the shock body. Using the appropriate hex wrenches (usually 8mm and 5mm), remove the bolts securing the shock’s top and bottom mounts. Once you’ve done this, carefully separate the shock body from the damper unit. Take note of the order of washers, O-rings, and seals to ensure proper reassembly.
4. Clean the Shock Components
Clean all components using isopropyl alcohol and a clean rag. Pay particular attention to areas where dirt and debris may have accumulated, such as the seal area and around the shock’s body. Use a small brush to gently scrub any stubborn dirt from the shock’s external parts, ensuring that no contaminants remain.
5. Inspect and Replace Damaged Parts
Inspect the O-rings, seals, and bearings for wear. Any components that appear damaged or worn should be replaced. The DHX2 Trunnion uses high-quality seals, but over time they can become brittle or tear, reducing the shock’s performance. Pay attention to the damper’s shaft as well, ensuring it is free from scratches or signs of damage.
6. Lubricate the Components
Apply a thin layer of silicone grease to the seals and O-rings to facilitate smooth movement and prevent wear. Avoid over-greasing, as excess grease can attract dirt. If necessary, apply a small amount of Fox-specific oil to the damper shaft to reduce friction and improve performance.
7. Reassemble the Shock
Once the shock components are cleaned and lubricated, reassemble them in the reverse order of disassembly. Ensure that all seals, O-rings, and washers are positioned correctly. Pay close attention to the orientation of the parts as you reassemble the shock. Tighten all bolts to the manufacturer’s recommended torque settings, using a torque wrench [paid link] for precision.
8. Set the Proper Preload and Pressure
With the shock reassembled, you now need to set the proper preload on the coil spring. Start by sliding the coil spring back onto the shock body. Adjust the preload using the preload adjuster until you achieve the desired sag according to your weight and riding style.
Next, use a shock pump to set the air pressure in the air spring side (if your DHX2 model uses it). Check the manufacturer’s specifications for the recommended pressure based on your weight.
9. Test the Shock
Before re-installing the shock on your bike, test it by compressing it by hand to ensure it feels smooth and responsive. If you notice any resistance or rough spots, the shock may need further disassembly for inspection or additional lubrication.
10. Reinstall the Shock
Once you are satisfied with the performance of the shock, carefully reinstall it onto your bike. Tighten the mounting bolts to the specified torque settings. After installation, check for any play or movement in the shock to ensure it is securely attached.
Troubleshooting Common DHX2 Trunnion Rear Shock Issues
1. Loss of Rebound Control
If your rebound damping feels weak or non-responsive, it could be due to air or fluid leakage inside the shock. First, check the air pressure and make sure it matches the recommended levels. If the problem persists, you may need to replace the shock oil or seals, as they could be worn out or damaged.
2. Excessive Stiction
Excessive stiction is often caused by dry seals or insufficient lubrication. Check the seals and O-rings for wear and replace them if necessary. Additionally, ensure that the shock shaft is properly lubricated with silicone grease to reduce friction.
3. No Compression Damping
If there’s no compression damping, the shock may have lost its oil or internal components could be damaged. Remove the damper and inspect it for any signs of damage, including worn valves or seals. If the damper is faulty, it will need to be rebuilt or replaced.
Customization and Optimization
The DHX2 Trunnion rear shock can be fine-tuned to meet your riding preferences. Adjusting the preload on the coil spring and setting the air pressure can drastically change the shock’s performance. Additionally, the rebound and compression adjustments allow you to tailor the shock’s behavior to suit different terrains.
For aggressive riders or those seeking maximum comfort, consider experimenting with different spring rates. A stiffer spring offers more support for heavy riders or rough terrain, while a softer spring offers better compliance for lighter riders or smoother trails.
Compatibility with Other Drivetrain Components
The DHX2 Trunnion rear shock is compatible with a wide range of drivetrain components, particularly those designed for aggressive mountain biking. However, compatibility with certain frame designs and suspension systems should be verified before installation. The shock is designed to work best with frames that have a trunnion mount, so be sure that your bike frame supports this type of mounting before purchasing the DHX2 rear shock.
Conclusion
Servicing your DHX2 Trunnion rear shock at home is a feasible task that can save you both time and money. By following this step-by-step guide, you’ll be able to keep your shock in peak [paid link] condition, ensuring smoother rides and longer-lasting performance. Regular maintenance, proper lubrication, and seal inspections are key to optimizing the functionality of the DHX2 Trunnion rear shock and making the most of your mountain biking experience.