RGP 25,000 lbs Gooseneck to 5th Wheel Trailer Coupler Adapter - Square

Name: RGP 25,000 lbs Gooseneck to 5th Wheel Trailer Coupler Adapter - Square
Brand: RunningGearParts.com
SKU: JC-25K-5G-SQ-M
Price: 210.49 USD
Availability: InStock

$210.49 USD

Shipping calculated at checkout.

Care information

To ensure optimal performance and extend the service life of your new trailer components, please follow these care guidelines after purchase:

Before installation, check all parts for shipping damage or missing components. Do not install damaged parts.
Always use correct tools and torque settings. Improper installation can lead to premature wear or failure.
For bearings, suspensions, and brake components, apply high-quality trailer grease before first use if not pre-greased.
Some parts (like brake assemblies) require a short break-in period to achieve full performance. Follow manufacturer instructions for best results.
Recheck fasteners, grease levels, and moving components after 100 miles of towing, then at regular intervals.
After exposure to water, road salt, or mud, clean and dry parts thoroughly. Apply anti-rust treatment if needed.
If storing unused parts, keep them in a dry, sealed container away from moisture and direct sunlight.

Delivery and Shipping

Handling Time: Orders ship out within 1 business day after payment is received.

Shipping Methods: We use trusted carriers like UPS, FedEx, or USPS based on package size and destination.

Delivery Time: Estimated delivery within 2–6 business days (U.S. domestic orders).

Tracking: A tracking number will be provided once your order is dispatched.

Q1 Will this brake fit my trailer?

This brake assembly fits most standard 7,000 lb trailer axles that use 12" × 2" electric brakes with a 5-bolt mounting flange. Please verify your axle rating and brake dimensions before ordering. If you're unsure, send us your axle tag or hub information and we'll help confirm compatibility.

Q2 Does it fit Dexter or Lippert axles?

Yes. It is compatible with many standard Dexter, Lippert, Rockwell American, AL-KO, and other 7,000 lb trailer axles that use a standard 12" × 2" brake assembly. Always verify your axle specifications before purchasing.

Q3 Is this a self-adjusting brake?

Yes. This is a self-adjusting electric brake assembly, which automatically maintains proper brake shoe clearance during normal operation. This reduces maintenance and helps provide consistent braking performance.

Replacement & Compatibility:

Fitment: Inserts into standard 4-1/2" outer width square gooseneck coupler outer tubes.
Function: Adapts a square gooseneck trailer setup to hook up to a standard 5th wheel kingpin coupler.
Interchangeable Part Numbers: Ram KP5G-Q25.

Specifications:

Weight Capacity: 25,000 lbs (M.G.T.W.)
Tube Shape: Square
Inner Tube Width (O.D. of this adapter): 4"
Fits Outer Tube Width (I.D. of receiver): 4-1/2"
Overall Length: 20"
Kingpin Plate Dimensions: 10" Long x 10" Wide
Range of Vertical Adjustment: 8"
Pin Hole Diameter: 7/8"
Pin Hole Spacing: 2-11/16" (measured from center of hole to center of hole)
Finish: Raw steel (optimized for clean, heavy-duty welding)

What's Included:

1 x Square Gooseneck-to-5th-Wheel Kingpin Adapter Tube (25,000 lbs)

Note: Outer receiver tube, set screws, and frame mounting hardware are NOT included.

Product Overview:

Convert your square gooseneck trailer to a standard 5th wheel setup with this heavy-duty 25,000 lb rated adapter. Constructed from high-strength raw steel, this 4" square inner tube features a solid 10" x 10" base plate integrated with a standard 5th wheel kingpin. Designed to slide into standard 4-1/2" outer square receiver tubes, it offers up to 8" of vertical height adjustment with pre-cut 7/8" pin holes spaced at 2-11/16" increments, ensuring a secure and optimized towing height for heavy-duty commercial or industrial trailers.

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