HySecurity MX3621, Belt and Pulley, Kit, 15mm

HySecurity MX3621, Belt and Pulley, Kit, 15mm

The HySecurity MX3621 is a 15mm wide timing belt and motor shaft pulley kit used on StrongArmPark DC barrier operators. It is specifically known as the replacement for the older narrow 8mm belt and motor shaft pulley used on 2014 and older models. Because the belt and pulley work as a matched drive set, ordering only by belt width can create fitment problems if the existing pulley is different.

This kit is typically replaced when the belt is cracked, frayed, glazed, stretched, slipping under load, or when the older 8mm belt system is being updated to the 15mm setup. A failed belt may stop the arm from moving, cause jerky arm travel, or allow motor rotation without proper movement at the barrier mechanism. Inspect the pulley teeth, motor mount, belt tension, and arm balance before final testing.

Compatible With

• HySecurity StrongArmPark DC operators using the 15mm belt and pulley setup.
• 2014 and older StrongArmPark DC models being updated from the narrow 8mm belt and motor shaft pulley, when the parts diagram supports MX3621.
• Barrier arm drive systems that call for MX3621 as the belt and pulley service kit.
• Not a universal belt for all StrongArm, StrongArmCrash, or StrongArmPark generations.
• Verify belt width, pulley type, motor shaft, and production generation before ordering.

Features & Specifications

Also Known As / Related Part Numbers

• MX3621
• HySecurity MX3621
• Hy-MX3621
• HYS-MX3621
• Belt and Pulley Kit 15mm
• 15mm Timing Belt and Motor Shaft Pulley
• StrongArmPark DC Belt and Pulley Kit
• 8mm to 15mm belt update reference

Technician Note

If the belt failed early, check arm balance, bearing drag, pulley alignment, motor mount movement, and belt tension. A tight or unbalanced arm can overload a new belt.

Before Ordering

• Confirm the operator is a StrongArmPark DC.
• Check whether the existing setup is the older 8mm belt system or the 15mm system.
• Verify the pulley and belt are being replaced as the correct matched kit.
• Inspect pulley teeth, belt path, motor mount, and arm balance.
• Set belt tension according to the operator service instructions.

Professional Advisory

Do not force a mismatched belt onto the wrong pulley. A belt that is too narrow, too wide, or incorrect tooth pitch can damage the motor shaft pulley and cause unreliable barrier movement.

Questions & Answers

What is included in the MX3621 kit?

The MX3621 kit includes a 15mm wide timing belt and matching motor shaft pulley for supported StrongArmPark DC operators.

Which operator is MX3621 compatible with?

It is compatible with HySecurity StrongArmPark DC applications where the parts diagram calls for the 15mm belt and pulley kit.

Does MX3621 replace the older 8mm belt setup?

Yes, it is commonly listed as the replacement for the narrow 8mm belt and motor shaft pulley on 2014 and older supported models.

Can I replace only the belt?

This part is a belt and pulley kit. The pulley match matters, especially when updating from the older narrow belt setup.

What causes repeated belt failure?

Incorrect tension, arm imbalance, pulley misalignment, worn pulley teeth, bearing drag, or a binding barrier mechanism can cause repeated belt failure.