SCX30 Oil Shock Setup Guide: How to Fill, Tune & Maintain

The performance of oil shocks depends on proper setup and regular maintenance. When used with shock oil, factors such as oil viscosity and oil level affect damping, while cleaning and inspection help keep the shocks moving smoothly and consistently.

In this guide, we'll use INJORA SCX30 aluminum oil shocks to show you how to properly fill, tune, clean, and maintain oil shocks.

For the INJORA SCX30 aluminum oil shocks featured in this guide, using shock oil is optional and depends on your setup and driving preferences. When filled with shock oil, the damping can be adjusted by choosing different oil viscosities. If you choose to run these shocks without oil, you can skip the filling and shock oil tuning sections and continue to the cleaning and maintenance section.

How to Fill SCX30 Oil Shocks

Follow these six steps to fill the shocks, remove trapped air, and reassemble them correctly.

Before you begin, prepare your shock oil and tools. For INJORA aluminum oil shocks for SCX30, 10-20wt oil is a good starting point. Due to the compact size, a syringe or fine-tip filling tool may be needed to add the oil.

Step 1: Disassemble the Shock

Remove the spring, spring retainer, and top cap, then take out the shock shaft, O-rings, and other internal parts. Keep the parts in order so the shock can be reassembled correctly.

Step 2: Lubricate the O-Rings

Apply a small amount of grease to the O-rings before reinstalling them. This reduces friction between the O-rings and the shock shaft and helps the seals work properly.

Step 3: Reinstall the Shock Shaft and Add Shock Oil

Reinstall the O-rings and shock shaft in the correct order, then slowly add shock oil until the oil reaches the top of the shock body. Add the oil gradually to help reduce the amount of air introduced during filling.

Step 4: Remove Trapped Air

Slowly move the shock shaft up and down to release air trapped in the oil. Then keep the shock upright for a short while so the remaining bubbles can rise to the surface. Removing trapped air helps maintain consistent damping.

Step 5: Adjust the Oil Level and Reinstall the Top Cap

Once the visible air bubbles are gone, adjust the oil level and reinstall the top cap. Slowly compress the shock through its full travel to make sure it moves smoothly.

If the shock cannot fully compress, do not force it. First, check whether too much oil has been added, then confirm that the shock is assembled correctly. Adjust the oil level or reassemble the shock if needed before testing it again.

Step 6: Reinstall the Spring and Other Parts

Reinstall the spring, spring retainer, and the remaining parts to complete the assembly. Once everything is in place, the shock is ready to be reinstalled on the vehicle.

How to Tune SCX30 Shock Damping

Shock oil controls how quickly the suspension compresses and rebounds.

• Thinner oil allows faster shock movement and quicker response to small bumps.
• Thicker oil slows shock movement and provides more controlled damping.

If the suspension feels too bouncy, try slightly thicker oil. If the suspension reacts too slowly, try slightly thinner oil.

Keep in mind that shock oil controls movement, while the springs support the vehicle’s weight. If the crawler sits too low at rest, check the spring preload and spring rate. If the suspension bottoms out easily over bumps or drops, check the spring setup and available compression travel; slightly thicker oil may also help.

Tip: Change only one setting at a time and test after each adjustment.

How to Clean and Rebuild SCX30 Oil Shocks

For routine maintenance, simply wipe away dirt and check the shocks. You don’t need to take them apart after every run. If they start to bind, the damping changes noticeably, or they keep leaking oil, it's time for a closer inspection. The steps below show you how to disassemble, clean, inspect, and reassemble the shocks.

Step 1: Disassemble the Shock

Remove the shock from the vehicle, then take apart the spring, spring retainer, top cap, shock shaft, and any other parts that need cleaning. If there is old shock oil inside, drain it out during disassembly.

Step 2: Clean the Parts

Clean the shock body, spring, shock shaft, and other parts to remove dirt, sand, old oil, and debris. Pay extra attention to the shock shaft and seals, making sure no dirt or sand is left behind.

Step 3: Dry the Parts

Wipe each part with a clean cloth or paper towel and make sure everything is clean and completely dry before reassembly.

Step 4: Reassemble the Shock

Reassemble the cleaned parts in the correct order.

During reassembly, check the O-rings and shock shaft for any signs of damage. If the O-rings are damaged or the shaft is scratched or bent, replace the affected parts before using the shock again.

If you plan to refill the shock with oil, leave the top cap off for now and continue to the next step.

Step 5: Refill with Shock Oil (If Used)

If you run these shocks with shock oil, refill the shock, remove any trapped air, and adjust the oil level as needed. For detailed filling and air removal instructions, refer to the "How to Fill SCX30 Oil Shocks" section above.

Step 6: Check and Test the Shock

Slowly compress the shock several times to make sure it moves properly and rebounds as expected. Check for binding, unusual resistance, or oil leaks. If everything works normally, reinstall the shock on the vehicle.

SCX30 Oil Shock Video Tutorials

For a closer look at the process, watch our step-by-step SCX30 oil shock tutorials below:

How to Fill INJORA Aluminum Oil Shocks for 1/30 SCX30

How to Rebuild RC Oil Shocks: Clean, Reassemble & Refill

FAQ

How Often Should You Service SCX30 Oil Shocks?

There is no fixed service schedule. If you often drive in mud, sand, dust, or wet conditions, clean and inspect the shocks more frequently. For regular use, simply wipe away dirt and check the shocks—you do not need to disassemble them after every run. If the shocks no longer move smoothly, the damping changes noticeably, or you notice ongoing oil leaks, it’s time for a more thorough inspection and service.

Why Does My Shock Feel Stiff Near the End of Its Travel?

If the shock becomes unusually stiff near the end of its travel or cannot fully compress, do not force it. First, check whether too much shock oil has been added, then confirm that the shock is assembled correctly. Adjust the oil level or reassemble the shock if needed before testing it again.

When Should I Replace the O-Rings or Shock Shaft?

Replace the O-rings if they are damaged, and replace the shock shaft if it is scratched or bent. Check both parts during routine maintenance before reassembling the shock.

What Shock Oil Should I Use for SCX30 Oil Shocks?

There is no single shock oil viscosity that works best for every SCX30 setup. For INJORA SCX30 oil shocks, a light oil such as 10–20wt can be a good starting point, then adjust based on vehicle weight, springs, terrain, and driving style.