The Fox DHX2 Performance Elite [paid link] rear shock is a high-performance component designed for aggressive mountain biking. Regular maintenance, particularly oil changes, is essential to ensure optimal performance and longevity. This guide will walk you through the process of changing the oil in your DHX2 rear shock, focusing on the necessary steps, tools, and tips for a successful oil change.

Tools Required

• Fox DHX2 shock service kit
• 8mm and 10mm socket wrenches
• Torque wrench [paid link]
• T25 Torx driver
• Needle-nose pliers
• Shock pump
• Rags and gloves for cleanliness
• 5mm and 6mm Allen wrenches [paid link]
• Fork oil (or Fox recommended oil for DHX2)
• Shock oil syringe or measuring tool
• Threadlocker (if needed)

Preparing the Rear Shock for Service

Before beginning the oil change process, ensure that your bike is in a stable position, preferably in a repair stand. This provides easier access to the shock and minimizes the risk of any accidental damage.

1. Remove the Shock from the Bike: Begin by carefully removing the rear shock from your bike. Use the appropriate wrenches to loosen the bolts that attach the shock to the frame. Support the shock as you remove it to avoid damaging the mounting hardware.
2. Clean the Shock: Thoroughly clean the shock’s exterior with a rag, ensuring that no dirt or debris enters the shock body during the disassembly process. Use a clean, dry rag to remove any excess grime from the shock’s surface.

Disassembling the DHX2 Rear Shock

The Fox DHX2 rear shock consists of several internal components, including the air chamber, oil damper, and compression adjustments. Here’s how to disassemble it carefully:

1. Loosen the Compression Adjuster: Using a T25 Torx driver, remove the compression adjustment knob from the shock. Be gentle to avoid stripping any parts. Set this aside in a safe place.
2. Remove the Schrader Valve: Using a 5mm Allen wrench [paid link], carefully remove the Schrader valve from the shock. This is where the air pressure is added, and it is important not to damage the threads or valve during this step.
3. Remove the Shock’s Eyelet: Using the 8mm and 10mm socket wrenches, carefully remove the eyelet bolts. This will allow you to completely disassemble the shock and begin draining the oil.

Draining and Changing the Oil

Now that you’ve removed the external components, you can proceed with draining the oil and replacing it with fresh oil.

1. Drain Old Oil: Place a container or a clean rag under the shock to catch any oil. Carefully remove the oil fill bolt using the 6mm Allen wrench [paid link]. Let the shock drain completely, ensuring all the old oil is removed. You may need to slightly compress the shock to force out any remaining oil.
2. Inspect for Contaminants: Once the shock has drained, inspect the oil that was removed. If you notice any significant debris, contaminants, or abnormal color (e.g., darkened or thickened oil), this indicates wear or damage to internal seals and components. It is advisable to inspect and replace seals if necessary.
3. Clean the Internal Components: Use a rag to wipe the shock internals clean. Pay special attention to the piston and the body of the shock, as any buildup of grime could interfere with the oil’s performance. Use a small amount of suspension cleaner if necessary.
4. Reassemble the Internal Components: Once cleaned, replace the internal components of the shock, including the piston and seals. If any parts appear worn or damaged, replace them using the Fox DHX2 service kit. Install the oil damper and ensure that everything is in its proper place before moving forward.

Replacing the Oil

Once you’ve cleaned the shock and replaced any damaged components, it’s time to refill it with fresh oil.

1. Measure the Correct Oil Volume: Refer to your DHX2 Performance Elite [paid link] owner’s manual for the recommended oil volume. Typically, Fox recommends using their own suspension fluid for best results. Using a shock oil syringe or measuring tool, carefully add the recommended amount of oil into the shock reservoir.
2. Check for Air Bubbles: After filling the shock with oil, gently compress the shock to release any trapped air. Continue to compress it until no more air bubbles are visible in the oil. This step is crucial to maintaining consistent shock performance.
3. Seal and Tighten: Once the shock is filled with the correct amount of oil, reinstall the oil fill bolt and tighten it securely with a torque wrench [paid link]. Be careful not to overtighten, as this could damage the shock. Follow the recommended torque specifications provided by Fox for this part.

Reinstalling the Shock

Now that your DHX2 rear shock has been serviced, it’s time to reinstall it on the bike.

1. Attach the Shock to the Frame: Carefully align the shock with the mounting points on your bike frame. Reinstall the eyelet bolts and tighten them securely using your 8mm and 10mm socket wrenches.
2. Reinstall the Schrader Valve: Screw the Schrader valve back into place using a 5mm Allen wrench. Ensure that the valve is seated properly, and avoid over-tightening it.
3. Reinstall the Compression Adjuster: Finally, reinstall the compression adjuster knob onto the shock, ensuring it’s securely tightened with the T25 Torx driver.

Setting the Air Pressure and Testing

1. Set the Correct Air Pressure: Use a shock pump to inflate the shock to the correct pressure, based on the rider’s weight and riding style. Follow the manufacturer’s guidelines for your weight and intended use to find the ideal pressure.
2. Test the Shock: With the shock reinstalled, carefully test the bike by compressing the shock by hand. Ensure that the suspension feels smooth and responsive. If you experience any unusual stiffness or noise, double-check the oil level and internal components.

Troubleshooting Common Issues

If the shock isn’t performing as expected after an oil change, consider the following:

1. Stiffness or Lack of Travel: This could indicate air trapped inside the shock. Re-bleed the shock to remove air bubbles.
2. Leaking Oil: Check the oil fill bolt and Schrader valve to ensure they’re properly tightened. If leaking persists, inspect the seals and replace them if necessary.
3. Reduced Performance or Sag: If the shock feels overly soft or sluggish, you may need to adjust the air pressure or oil volume to optimize performance.

Conclusion

Changing the oil in your Fox DHX2 Performance Elite rear shock is a critical part of regular maintenance. By following the steps outlined above, you can ensure your shock operates at peak [paid link] performance, providing a smoother, more controlled ride. Regular oil changes also extend the lifespan of your shock, keeping it functioning optimally for many rides to come. Always remember to check for compatibility and adhere to manufacturer guidelines when performing maintenance tasks.