Gooseneck Trailer Coupler / Heavy-Duty Towing Component
Bulldog BX1 2-5/16" Round Gooseneck Coupler - 25K Capacity | 4.5" Outer Tube
Heavy-duty Bulldog BX1 round tube gooseneck coupler assembly for 2-5/16" hitch balls. Built for high-capacity gooseneck trailer applications requiring a 4.5" outer tube and adjustable inner coupler tube.
Part Number: D0289360300 2-5/16" Gooseneck Ball 25,000 lb Capacity
Specifications
| Specification |
Detail |
| Part Number |
D0289360300 |
| Brand |
Bulldog |
| Product Type |
Round tube gooseneck coupler assembly |
| Application |
Heavy-duty gooseneck trailers |
| Ball Size |
2-5/16" gooseneck hitch ball |
| Outer Tube |
4.5" O.D. round outer tube |
| Inner Tube |
4" O.D. round inner tube |
| Vertical Adjustment |
8" adjustment range |
| Retracted Height |
29.3" |
| Capacity |
25,000 lbs gross trailer weight rating |
| Pin Size |
3/4" load-bearing pin |
| Material / Finish |
High-strength steel / raw and painted components |
Fitment / Application
| Category |
Details |
| Vehicle / System |
Adjustable round tube gooseneck hitch system |
| Primary Fit |
Gooseneck trailers using a 4.5" O.D. round outer tube and 2-5/16" hitch ball |
| Trailer Applications |
Horse trailers, livestock haulers, heavy equipment flatbeds, and other compatible high-capacity gooseneck trailers |
| Capacity Reference |
25,000 lbs gross trailer weight rating |
| Notes |
Verify tube size, ball size, capacity requirement, retracted height, adjustment range, pin size, and weld-in mounting requirements before installation. |
Overview
This Bulldog BX1 round gooseneck coupler is designed for heavy-duty trailer applications that use a 2-5/16" gooseneck ball and a 4.5" O.D. outer tube. The BX1 design uses a self-centering locking plate to help make trailer hookup easier while maintaining a secure connection for demanding towing use.
R&P Service Insight
Gooseneck couplers see constant exposure, load stress, and repeated hookup cycles. Correct fitment, proper pin engagement, and condition checks are critical before towing.
-
Wear: Moving locking components can lose tolerance over time, which may create looseness at the hitch ball.
-
Exposure: Raw steel weld areas should be properly finished after installation to help reduce corrosion risk.
-
Load Stress: Frequent heavy braking, sharp starts, and high-load use can accelerate wear around adjustment holes and bearing points.
R&P Knowledge Hub
Compatibility: Designed for standard 2-5/16" gooseneck hitch balls and compatible round tube gooseneck trailer setups using a 4.5" O.D. outer tube.
Vehicle / System Fit: Used on heavy-duty gooseneck trailer systems including compatible horse trailers, livestock trailers, flatbeds, and equipment hauling trailers.
Installation Notes: The outer tube is intended to be welded into the trailer gooseneck structure. Verify all tube dimensions, adjustment hole alignment, pin engagement, and coupler height before towing.
Performance Insight: The BX1 self-centering locking plate helps guide the ball into position during hookup, making alignment easier than traditional coupler designs.
Brand & Fitment Note
Selling Brand: Bulldog
Application Reference: Trailer type and system references in this listing describe compatible gooseneck trailer applications where measurements, capacity requirements, and mounting configuration match.
What This Means: This listing is for a Bulldog BX1 gooseneck coupler assembly for listed round tube gooseneck applications.
Before Ordering: Verify ball size, tube size, trailer capacity requirement, pin size, height range, weld-in mounting requirements, and included components before installation.
R&P Repair Insight
When replacing a gooseneck coupler, match the tube dimensions and capacity rating carefully. A coupler that appears similar may not be correct if the outer tube size, inner tube diameter, pin size, or adjustment range differs.
-
Tube Size Check: Confirm the trailer is set up for a 4.5" O.D. round outer tube and 4" O.D. inner tube configuration.
-
Pin Engagement Check: The 3/4" load-bearing pin must pass fully through the adjustment holes and be secured before towing.
-
Weld Area Check: After installation, weld areas and raw steel surfaces should be protected according to proper trailer repair practices.
Features
BX1 Self-Centering Design
Self-centering locking plate helps guide the gooseneck ball into the coupler for easier hookup and a secure connection.
Heavy-Duty Gooseneck Capacity
Rated for 25,000 lbs gross trailer weight, making it suitable for compatible high-capacity gooseneck trailer applications.
Standard 2-5/16" Ball Fit
Designed for common 2-5/16" gooseneck hitch balls used on heavy-duty towing setups.
Adjustable Round Tube Assembly
Includes a 4.5" O.D. outer tube, 4" O.D. inner tube, and 8" vertical adjustment range for compatible trailer installations.
Included Components
| Quantity |
Item |
| 1 |
Round outer tube, 4.5" O.D. |
| 1 |
Round inner tube with BX1 coupler head, 4" O.D. |
| 1 |
3/4" load-bearing pin and bridge clip |
| 1 |
Locking set screw |
Verify all specifications, measurements, tube sizes, ball size, load rating, weld-in requirements, pin engagement, and included components before installation. Always ensure the 3/4" load-bearing pin is fully seated and clipped before towing.
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