9K-10K GD Trailer Spindle
This Dexter-compatible 9K–10K General-Duty (#99) spindle is a go-to on equipment haulers, deckovers, and heavy dump trailers, and its compatibility with widely stocked hubs, drums, and hardware keeps service simple and affordable.
Built from high-strength, heat-treated steel and precisely machined at all bearing and seal surfaces, this spindle is designed for long-term performance under heavy payloads and frequent use. Its construction supports smooth bearing operation, proper tracking, and reduced wear on tires, brakes, and suspension systems.
| Recommended Fit For: | General-duty, utility trailers. Dexter, Dexter-compatible axle type |
| Heat Treatment: | Yes |
| Weight Rating: | 9,000 lbs - 10,000 lbs Axle rating |
| Product Weight: | 25 lbs |
| Product Dimensions: | Inner Bearing: 57.15mm, Outer Bearing: 44.45mm, Wheel Seal: 73.025mm, Nut: 38mm |
| Compatible Parts: | Inner Bearing: Timken 387A-20024, Outer Bearing: Timken 25580, Seal: SKF 28778 |
| Warranty: | 1-Year Limited Warranty |
Description
Each spindle is thoroughly inspected for surface finish, material integrity, and runout before shipping. Backed by a 1-year limited warranty, this is a reliable, service-friendly solution for replacing Dexter 10K spindles. Professional installation is recommended for proper alignment and optimal durability.
Whether you’re towing compact equipment, operating a loaded dump, or managing a small fleet, a dependable GD trailer spindle is the backbone of safe, stable, and consistent operation. If your wheel-end calls for the classic 9K/10K GD hardware combo, this replacement delivers the right fit with parts you can source anywhere.
Is this the right spindle for the job?

Trailer Compatibility – Parts List
This spindle is designed to fit the standard #99 spindle family used across most Dexter trailer axles in the 9K–10K range.
Compatible parts/hardware include:
- Inner Bearing: Timken 387A-20024
- Outer Bearing: Timken 25580
- Seal: SKF 28778
Confirm on your trailer: pull the hub and read the numbers stamped on the bearing/race (cup).
If you’re still in doubt, contact us and we’ll help you find the right product.
9K-10K Trailer Spindle – Frequently Asked Questions
What’s the difference between the Dexter-compatible 5.2K-7K and 9K/10K GD spindles?
- 5.2K–7K (#42) spindles use smaller, grease-lubricated bearings: typically 25580 inner / 15123 or 14125A outer.
- 9K/10K GD (#99) spindles are larger, oil-bath setups using 387A inner / 25580 outer bearings and a 2.875″ oil seal.
Note: #42 and #99 components are not interchangeable.
How can I tell if my trailer has #42 (5.2K–7K) or #99 (9K/10K GD) spindles?
Look for three quick identifiers:
1. Bearing Cone Numbers
- #42 (5.2K–7K): Inner = 25580
- #99 (9K/10K GD): Inner = 387A, Outer = 25580
2. Seal ID #99 GD uses a 2.875″ oil seal (e.g., Dexter 010-051-02)
3. Brake Drum Size #99 GD drums are 12.25″ × 3-3/8″, often marked “9-44” (e.g., Dexter 009-044-01)
Note: While #42 hubs typically use grease seals, specific seal dimensions vary by hub model and are not standardized across all #42 applications.




