The Genie 66777GT Top Lock Nut, 1/2-13 is a genuine OEM fastener built for Genie GS scissor lifts, S and SX telescopic boom lifts, and Z articulating boom lifts. As a direct OEM replacement, this nut is manufactured to the same standards as the original hardware installed at the factory, ensuring a correct fit with no guesswork. Cross-reference part number 66777GT against your machine's parts manual to confirm it is the right component for your specific unit. Compatible models include the GS-2032, GS-2632, GS-2046, GS-2646, S-100HD, S-120HD, SX-180, Z-80/60, Z-135/70, and ZX-135/70.
Key Features
- Genuine OEM Construction — Manufactured to Genie's original dimensional and material specifications, delivering the correct thread engagement and locking force for a 1/2-13 fastener application.
- Exact-Match Thread Spec — The 1/2-13 thread size matches the original hardware precisely, allowing straightforward installation without modification to mating components.
- Broad Genie Fitment — Compatible with GS scissor lifts, S and SX telescopic booms, and Z and ZX articulating booms across multiple configurations.
- Vibration-Resistant Locking Design — The top lock profile resists loosening under the vibration and dynamic loading common in aerial lift operation, helping fastened joints stay secure between service intervals.
A top lock nut uses a deformed or prevailing-torque thread section at the top of the nut to grip the bolt thread and resist loosening caused by vibration or cyclical loading. Once tightened, the locking element maintains clamping force without relying on a secondary locking device such as a split washer. A nut that has lost its locking effectiveness can back off gradually during operation, reducing joint clamping force and leading to movement in components that should remain rigid. Replacing worn or damaged hardware with the correct OEM nut restores the joint to its original holding specification.
Part Details
| Part Number | 66777GT |
|---|---|
| Brand | Genie |
| Part Type | Genuine OEM |
| Description | Top Lock Nut, 1/2-13 |
Compatibility & Fitment
| Name | Models |
|---|---|
| GS-2032 | GS-2032 |
| GS-2046 | GS-2046 |
| GS-2632 | GS-2632 |
| GS-2646 | GS-2646 |
| S-100HD | S-100HD |
| S-120HD | S-120HD |
| SX-180 | SX-180 |
| Z-80/60 | Z-80/60 |
| Z-135/70 | Z-135/70 |
| ZX-135/70 | ZX-135/70 |
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.
