The Wacker Neuson 5200020016 is a genuine OEM Lock Nut designed for the APT4S and APT4T pump series, including skid-mounted, electric brake, surge brake, and cold weather configurations. As a direct OEM component, it is manufactured to the exact specifications required for proper fastener retention and secure assembly within these trailer-mounted pump units. This part fits the APT4S Pump with Skid, APT4T Pump with Electric Brake, APT4T Pump with Surge Brake, and all corresponding cold weather variants. Keeping critical fasteners like the 5200020016 up to spec ensures the pump assembly stays correctly secured during transport and operation.
Key Features
- Genuine OEM Thread Integrity — Manufactured to exact thread pitch and hardness specs, ensuring the nut seats and torques correctly without stripping or backing off under load.
- Drop-In Replacement — Matches the original fastener profile so it installs directly into the existing assembly position without modification to mating hardware.
- Broad APT4S and APT4T Coverage — Confirmed fitment across skid, electric brake, surge brake, and cold weather variants of the APT4S and APT4T pump series.
- Locking Retention Under Vibration — The lock nut design resists loosening during pump operation and trailer transit, maintaining a secure assembly over extended service cycles.
- Transport Safety Compliance — On trailer-mounted pump units, properly torqued lock nuts are critical to safe road transport; using the correct OEM specification part supports proper fastener integrity.
A lock nut is a fastener engineered to resist loosening caused by vibration, dynamic loads, or repeated movement — all conditions common to trailer-mounted pump equipment like the APT4S and APT4T series. Unlike a standard hex nut, a lock nut incorporates a mechanical or friction-based locking feature that maintains clamping force even as the assembly flexes or vibrates during operation and towing. When a lock nut wears, strips, or is substituted with an incorrect fastener, it can allow critical components to work loose, compromising both the pump's performance and the safety of the trailer during transport.
Part Details
| Part Number | 5200020016 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Lock Nut |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| APT4S Pump w/Skid | APT4S | 5200018977 |
| APT4T Pump, Electric Brake | APT4T | 5200019644, 5200019643 |
| APT4S Pump w/Skid, Cold Weather | APT4S CW | 5200019798 |
| APT4T Pump, Electric Brake, Cold Weather | APT4T CW | 5200019793, 5200019792 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
