Replacing the elastomers on a Seating Dynamics Dynamic Rocker Back is a straightforward maintenance procedure that helps keep the backrest operating smoothly and as intended. Whether you're a clinician, ATP, wheelchair technician, or equipment provider, following the proper replacement process helps ensure the dynamic back continues to absorb movement and return to its neutral position correctly.

In this video, JJ walks through the entire replacement process step by step.

A written guide below highlights the key steps to follow.

Tools You'll Need

Before you begin, gather the following tools:

• 4 mm Allen key
• 5 mm Allen key
• 10 mm wrench
• 3/4 inch deep socket (or standard socket or wrench)
• Ratchet or impact driver (optional)

Step 1: Remove the Cover Plate

Use the 4 mm Allen key to remove the four screws securing the upper cover plate.

Before setting the cover plate aside, note its orientation for reinstallation. The beveled edge faces away from the wheelchair user toward the attendant, while the sharp edge and drill point face the user.

Step 2: Fold the Dynamic Back Forward

Using the 10 mm wrench and 5 mm Allen key, remove the angle adjustment bolt. This allows the Dynamic Rocker Back to fold forward, providing access to the hardware underneath.

Step 3: Remove the Actuator Hardware

Remove the 3/4 inch nut from the underside of the assembly. Carefully remove the actuator shaft and keep all washers, nuts, and hardware together for reassembly.

Step 4: Remove the Existing Elastomers

With the back folded forward, remove the impact elastomer and the clear rebound elastomer.

The impact elastomer absorbs the force when the user pushes against the backrest, while the rebound elastomer returns the back to an upright position in a smooth, controlled manner.

Step 5: Install the New Elastomers

Insert the new impact elastomer followed by the impact cap. Reinstall the actuator shaft and slide the new clear rebound elastomer into place.

Lightly thread the washer and nut to hold everything together before making final adjustments.

Step 6: Adjust and Tighten

Tighten the 3/4 inch nut until approximately four to five threads remain visible.

Check that the latch plate moves freely and latches and unlatches without binding. If necessary, make small adjustments until the Dynamic Rocker Back operates smoothly.

Reinstall the angle adjustment hardware and tighten it securely.

Step 7: Reinstall the Cover Plate

Replace the cover plate in its original orientation and tighten all four screws.

Perform a Final Function Check

Before returning the wheelchair to service, cycle the Dynamic Rocker Back through its full range of motion.

Verify that:

• The latch engages and releases smoothly.
• The back moves freely without excessive tension.
• Both sides operate consistently if elastomers were replaced on both sides.
• All hardware is fully tightened.

Once these checks are complete, the Dynamic Rocker Back is ready for use.

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