30K Gooseneck to 5th Wheel Adapter 4\" Round Drilled King Pin Wallace Forge For Sale

Gooseneck to 5th Wheel Conversion System

30K Gooseneck to 5th Wheel Adapter 4\" Round Drilled King Pin Wallace Forge

SKU: 2085205-DRILLED

Heavy-duty 4-inch round adapter designed to convert gooseneck trailers for use with standard 5th wheel hitches. Features pre-drilled holes for secure mechanical pinning and maximum height adjustability.


Fits 4\" I.D. Outer Tubes


30K GTW Heavy-Duty Build






Overview


The 2085205-DRILLED is a structural steel adapter that replaces the inner tube of a standard gooseneck coupler. By converting the connection point to a 2\" SAE Kingpin, this adapter allows you to pull your gooseneck trailer with a standard 5th wheel plate. The \"Drilled\" configuration is preferred for heavy-haul applications, as the pre-machined 7/8\" holes allow for a through-pin connection, providing a mechanical failsafe alongside traditional set screws.






R&P Service Insight


This adapter is essential for fleets or owners moving between different truck hitch configurations.

• Raw Steel: Shipped unpainted to allow for custom welding if required.
• Secure Pinning: Mechanical holes prevent tube \"creep\" under heavy loads.
• Standardized Fit: 2\" Kingpin works with all major 5th wheel hitch brands.

R&P Knowledge Hub

Compatibility: Designed specifically for trailers equipped with a 4\" Round outer gooseneck sleeve.
System Fit: Standard 2\" SAE Kingpin for use with 5th wheel hitches (RV or Commercial).
Installation Notes: Verify your outer tube diameter before ordering. Ensure set screws are torqued and safety pins are fully engaged.
Performance Insight: The 1/4\" wall structural steel construction and 8\" bolster plate are engineered to handle up to 30,000 lbs, providing a rigid, stable connection.


R&P Repair Insight


Before purchasing, confirm these critical measurements to ensure a safe and proper fit for your trailer conversion:

• Tube Diameter: Must be a 4\" Round Outside Diameter (OD) to fit standard outer tubes.
• Pin Alignment: Ensure your outer tube holes or set screws align with the 2-1/2\" hole spacing.
• Structural Integrity: Do not drill through the existing structural seams of the pipe if customizing.

Features




30K Weight Capacity
Sturdy construction rated for a Gross Trailer Weight (GTW) of 30,000 lbs.


Precision Drilled
Includes (4) sets of 7/8\" holes spaced 2-1/2\" apart for height adjustment.




Structural Steel Build
Features a 1/4\" wall thickness for maximum durability and safety.


8\" Bolster Plate
Provides a wide, stable contact surface for the 5th wheel hitch plate.






Specifications



Specification
Detail


Part Number
2085205-DRILLED


Product Type
Gooseneck to Kingpin Adapter


Max Capacity
30,000 lbs GTW


Material / Finish
Raw Structural Steel


Tube Diameter
4\" Round (O.D.)


Hole Size
7/8\" Diameter


Wall Thickness
1/4\" Heavy Duty


Pipe Length
20\" Total




Fitment / Application



Category
Details


Trailer Type
Gooseneck (Inner Tube Replacement)


Primary Fit
4\" I.D. Round Outer Tubes


Hitch Fit
Standard 2\" SAE 5th Wheel Plate


Notes
Verify your outer tube diameter and orientation before ordering.






Included Components



Quantity
Item


1
2085205-DRILLED Adapter Coupler (Raw Steel)


NOTE
Does not include through-pin or set screws (designed to use existing hardware).


Final Verification: Verify that your trailer requires a 4\" round inner tube. Check your hitch rating to ensure it meets or exceeds the weight of your loaded trailer. This adapter converts the connection type but does not increase your vehicle\'s towing capacity.


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