Our in-house experts typically reply within one business day.
Bulldog
Always the correct part
We know our products
Quality Products
Free Shipping!
Always the correct part
We know our products
Quality Products
Free Shipping!
Complete kit bundle containing all necessary components for your project. Professional-grade components designed for reliable performance and long-lasting durability.
Designed for utility, horse/livestock, cargo, and construction trailer applications, BULLDOG Collar-Lok are the strongest in the industry. The BULLDOG design features th eonly automatic and continuously tight ball fit in the industry. A variety of coupler styles, tongue mounts, and latches allow configurations to match virtually any trailer. Adjustable couplers assure level operation for trailers when pulled by a variety of different vehicles.
| BRAND: | BULLDOG |
| PART NUMBER: | 028387 |
| WARRANTY: | LIMITED 5 YEAR WARRANTY |
| WEIGHT: | 12.25 LBS |
| CAPACITY: | 7,000 LBS. |
| COLOR: | GRAY |
| MODEL NUMBER: | 3B4H |
| MATERIAL: | STEEL |
| BALL DIAMETER: | 2 IN. |
| MOUNTING HARDWARE INCLUDED: | NO |
| CHANNEL WIDTH: | 3 IN. |
| HITCH CLASS: | IV |
| SAFETY CHAINS INCLUDED: | NO |
Keywords: BD028387-20PK bundle kit, complete kit, professional components, industrial kit, BD028387, Bulldog
Founded in 1920, Bulldog has become the standard for heavy-duty trailer connection hardware in agricultural, military and utility service. The line covers gooseneck hitches and couplers, A-frame and channel-mount trailer couplers with the Wedge-Latch mechanism, and heavy-duty jacks, built for unmatched strength, reliability and safety under demanding loads.
Bulldog was founded in 1920 and has spent more than a century supplying the connection hardware that heavy trailers depend on. Its market has always been the demanding end: agricultural, military and utility applications where a coupler failure is not an inconvenience but a serious incident. The brand summarises its position as Tough and Tested, and it sits within the Horizon Global towing group alongside Reese, Draw-Tite, Fulton, Tekonsha, Bargman and Wesbar.
Gooseneck equipment is the brand's signature. Gooseneck hitches mount in the truck bed over the rear axle, which places the load where the chassis can carry it properly and allows far tighter turning than a receiver hitch permits. Matching gooseneck couplers attach at the trailer end, in round tube and square configurations across the capacity range used by livestock, equipment and flatbed trailers.
The conventional trailer coupler range is built around the Wedge-Latch mechanism, which uses a wedge to take up wear between coupler and ball rather than relying on a fixed clamp that loosens over time. That matters on a trailer accumulating hard miles, where slack in the coupling shows up as noise and shock loading. Couplers are offered in A-frame form for standard tongues and in channel-mount form for straight tongue and fabricated frames, with adjustable channel versions that let a coupler be positioned to suit the tongue height.
Heavy-duty jacks complete the line, sized for the tongue weights that gooseneck and equipment trailers generate. Across the range the emphasis is consistent: forged and heavy-section components, load ratings backed by testing, and hardware specified for agricultural, military and heavy-duty commercial use rather than occasional recreational towing.
Experts available to answer your questions
Call 888-634-94945 Years
The Bulldog Collar-Lok™ coupler is a trailer tongue coupler that connects a trailer to a towing vehicle via a hitch ball. It is available in models 2B, 3B, 4B, and 5B, each with different minimum tongue overlap requirements. The coupler features a collar mechanism that secures the hitch ball in the ball pocket and is held closed by a retaining pin. The product is rated according to SAE J684 safety standards.
Minimum tongue overlap depends on your coupler model: 2B, 4B, and 5B models require 8.5"; 3B model requires 6.5"; and some configurations allow 7" or as little as 2.5" (where the tongue may fit over or into the coupler). The coupler's internal stop must be butted against the end of the trailer tongue to achieve maximum overlap. Verify your specific model before installation.
No. The 3.0" channel is not included with the coupler. You must obtain the channel separately. The number and size of fasteners required to attach the coupler to the channel must be specified by the trailer manufacturer.
Use only the proper ball size for your coupler as indicated on the coupler body. If you are uncertain which size is correct, contact Cequent Performance Products at 1-800-632-3290 or www.cequentgroup.com. Using an incorrect ball size may result in unsafe operation.
The coupler comes with a retaining pin and supplied bolts. The exact number and size of bolts depend on your model. Grade 5 bolts with locknuts are required for bolt-on installation. Additional fasteners may be needed depending on your trailer and channel configuration, as specified by the trailer manufacturer.
Yes, if you are using a weld-on coupler, all welding must be performed by an AWS (American Welding Society) certified welder. Improper welding can result in coupler failure and safety hazards. If you are using a bolt-on coupler, professional welding is not required, but you must follow the bolt-on torque specifications and ensure the coupler is rigidly attached.
Before installation, confirm that there will be no interference from the tow vehicle, tongue, ground, or any other mounted accessories while stationary or in motion. Check for interference in both open and closed coupler positions. Ensure the coupler's internal stop will butt against the end of the trailer tongue for maximum overlap. After installation is complete, check for interference again and verify that coupler operation has not been impaired.
The manual does not specify whether drilling is required. The installation method depends on whether you are using a weld-on or bolt-on coupler. For bolt-on installation, the number and size of fasteners required must be specified by the trailer manufacturer. Contact Cequent Performance Products at 1-800-632-3290 for guidance specific to your trailer.
For weld-on installation, yes—the coupler is permanently welded to the trailer tongue with a 3/16" weld around the interface. For bolt-on installation, the coupler is attached with bolts and locknuts, which is reversible. In both cases, no deformation of the trailer tongue end is allowed. The coupler's internal stop must butt against the end of the tongue.
Torque grade 5 bolts with locknuts to the following SAE proof load specifications: 3/8" diameter bolts to 23 ft. lbs.; 1/2" diameter bolts to 55 ft. lbs.; 5/8" diameter bolts to 110 ft. lbs. These specifications apply to both initial installation and periodic retorque checks.
Channel hardware should be tightened to appropriate SAE proof load specifications. The manual references a torque range of 75-100 lb-pi for channel hardware checks, but the exact torque for your specific fasteners depends on their size. Use the torque specifications table (3/8" = 23 ft. lbs., 1/2" = 55 ft. lbs., 5/8" = 110 ft. lbs.) and verify with your trailer manufacturer if needed.
The manual does not describe any electrical connections for the coupler itself. However, the manual reminds you to ensure that all trailer lighting is hooked up and working properly before towing, as this is a separate safety requirement under SAE J684.
The maximum rated capacity is stamped on the coupler body or shown on decals. Do not exceed the lesser of the mounting bracket, coupler, hitch, vehicle, ball, or trailer weight ratings (including load). Weigh your trailer plus added load before towing. If you are uncertain about the capacity, contact Cequent Performance Products at 1-800-632-3290 or www.cequentgroup.com.
No. Do not tow if the ball is not fully seated in the coupler ball pocket and/or the coupler is not closed. Before towing, visually check that the hitch ball is fully seated in the coupler, close the coupler, and insert the retaining pin. Towing with an improperly seated ball or open coupler is unsafe and violates SAE J684 standards.
Always secure the load, vehicle, and trailer by blocking the wheels before latching or unlatching the coupler. Use caution when uncoupling as the tongue may rise suddenly due to negative tongue load. These precautions prevent injury and property damage.
Yes. Always secure safety chains to the towing vehicle and trailer according to SAE J684 before towing. This is a critical safety requirement and must be done every time you tow.
After installation is complete, check for interference again in both open and closed positions. Verify that coupler operation has not been impaired in any way. If the coupler operation is impaired, do not use it. Check that the coupler handle opens and closes freely. Check channel hardware for wear and proper tightness, and tighten to appropriate SAE proof load specifications using grade 5 hardware only.
Maintenance procedures should be performed at least annually. These include: checking welds and mounting bolt torque; greasing the ball pocket; oiling pivot points with SAE 30 weight motor oil; and inspecting retaining pins and replacing if necessary. Keep the ball pocket and mechanism clean at all times. When parking or storing your trailer, keep the coupler off the ground to prevent dirt and foreign material from building up in the ball pocket.
Grease the ball pocket annually. Oil pivot points with SAE 30 weight motor oil. Keep the ball pocket and mechanism clean. Do not use other lubricants unless specified by Cequent Performance Products.
Keep the ball pocket and mechanism clean by regularly inspecting and removing dirt and foreign material. When parking or storing your trailer, keep the coupler off the ground so dirt and other foreign material will not build up in the coupler ball pocket. Grease the ball pocket at least annually as part of routine maintenance.
If the coupler handle does not open and close freely, this indicates a problem with coupler operation. Do not use the coupler. Check the coupler for signs of wear or damage. If the coupler is deformed or damaged, replace the complete coupler and bracket. Contact Cequent Performance Products at 1-800-632-3290 for replacement parts.
If coupler operation has been impaired in any way after installation, do not use it. Check for interference with the tow vehicle, tongue, ground, or other accessories in both open and closed positions. Verify that the coupler is rigidly attached to the trailer. If the coupler is deformed or damaged, replace the complete coupler and bracket. Contact Cequent Performance Products at 1-800-632-3290 for assistance.
A sudden rise of the tongue when uncoupling is normal and is caused by negative tongue load. This is why you must always block the trailer wheels before uncoupling. Use caution and ensure the area is clear of people and obstacles before uncoupling. Never position any part of your body under the tongue or coupler during this operation.
The Bulldog Collar-Lok™ coupler is available in models 2B, 3B, 4B, and 5B with different minimum tongue overlap requirements (2.5" to 8.5" depending on model). Verify your model and that your trailer tongue meets the minimum overlap requirement. Contact Cequent Performance Products at 1-800-632-3290 if you are unsure.
No, the 3.0" channel is not included. You must obtain it separately. The number and size of fasteners required must be specified by your trailer manufacturer.
Yes, if using a weld-on coupler, all welding must be performed by an AWS certified welder. For bolt-on installation, professional welding is not required, but you must follow torque specifications and ensure rigid attachment.
Torque grade 5 bolts to: 3/8" = 23 ft. lbs.; 1/2" = 55 ft. lbs.; 5/8" = 110 ft. lbs. Use locknuts and tighten to appropriate SAE proof load specifications.
No. Do not tow without the retaining pin in place. The pin must be inserted behind the collar (L, M styles) or through the latch (H style) after the hitch ball is fully seated and the coupler cap is closed.
At least annually. Also check welds and mounting bolt torque, oil pivot points with SAE 30 weight motor oil, and inspect retaining pins for wear or damage.
Free Shipping
Ships free on all orders
Authorized Dealer
FREE ShippingFREE SHIPPING
Estimated delivery Tue, Aug 11 - Fri, Aug 14
Order before 2 PM EST Monday–Friday for same-day processing
Guaranteed safe & secure checkout
No reviews have been added for this product.
