The Premier Model 330 / 330A Hinge Assembly is a critical component designed for towing applications, specifically for full trailers. It functions as a hinge mechanism, allowing for rotational movement between the towing vehicle and the trailer, which is essential for proper trailer articulation and maneuverability. This assembly is designed to be used in pairs, ensuring stability and load distribution.

Function Description:

The hinge assembly facilitates the connection between a towing vehicle's front-end structure (typically 2 ½” round tubing) and a trailer's drawbar eye. It allows for controlled rotational movement, preventing binding or jackknifing during turns and over uneven terrain. The design incorporates a bushing system (either rubber or poly) to manage wear and provide a degree of shock absorption. Proper installation involves welding the 356 Housing to the front-end tube and the 350 Bracket to the mounting structure, ensuring precise alignment and flush fits to maintain the specified load capacities and operational integrity. The assembly's stiffness can be adjusted by tightening a locknut, allowing for customization based on desired rotational resistance.

Important Technical Specifications:

Max. Gross Trailer Weight (pair): 100,000 lbs. (45,359 kg). This indicates the maximum combined weight of the trailers that a pair of these hinge assemblies can safely support.
Bushing O.D.: 3 1/2 in. (89 mm). This refers to the outer diameter of the bushing, a key dimension for fitment and compatibility.
Bushing Length: 4 1/2 in. (114 mm). This specifies the length of the bushing, impacting the overall dimensions and stability of the hinge.
Unit Weight (pair): 50.2 lbs. (22.8 kg). This is the weight of a pair of hinge assemblies, useful for calculating overall vehicle weight.
Accepts: 2 1/2 in. (64 mm) round tubing. This specifies the diameter of the front-end tube that the 356 Housing is designed to accommodate.
Locknut Torque: 60 ft-lbs (initial), adjustable in 10-20 ft-lb increments, not to exceed 200 ft-lbs. This is crucial for setting the desired rotational stiffness and ensuring secure fastening.
351 Bolts Torque: 80 ft-lbs. These bolts compress the 350 Bracket, clamping the 359 Flange and 352 Taper pin.

Usage Features:

Pair Operation: The Model 330 / 330A Hinge Assemblies are designed to operate in pairs, requiring simultaneous installation and ensuring balanced load distribution.
Adjustable Stiffness: The rotational stiffness of the hinge can be adjusted by tightening the 321C Locknut, allowing users to customize the feel and response of the trailer connection.
Compliance with Regulations: Installation must comply with Federal Motor Carrier Safety Regulations, specifically Section 393.70, Paragraph C: “Towing of Full Trailers.” Users are advised to consult local, State, and Federal agencies for additional applicable laws.
Specific Bushing Replacements: Only Premier's 344 (Rubber) or 344A (Poly) Bushings should be used for replacement, ensuring compatibility and maintaining product warranty.
Clearance Requirements: A 3/8" gap must exist between the 356 Housing and 350 Bracket after installation, as shown in Figure 1, which is critical for proper function.
Warning Sticker: An "IMPORTANT WARNINGS!" sticker is enclosed and must be attached to the front end, adjacent to the drawbar eye, visible for the end user.

Maintenance Features:

Regular Visual Inspection: Before each use, the hinge assembly should be visually inspected for cracks, impact damage, and/or deformation. Any such conditions necessitate immediate discontinuation of use.
Scheduled Cleaning and Inspection: Every 90 days, or sooner depending on application, the hinge assembly should be cleaned and inspected for slack due to normal bushing wear.
Bushing Wear Check: To check for bushing wear, a crowbar should be placed near the center of the bracket adjacent to the housing, and pressure applied to test for free-play between the bushing and the housing or the bushing and the taper pin.
Bushing Adjustment/Replacement: If free-play is noted, the bushing should be tightened or replaced.
No Welding for Repairs: Damaged or worn Premier parts should never be repaired by welding, as field or shop weld repairs are inadequate and can weaken the hinge assembly, potentially voiding the warranty.
Use of Premier Parts Only: Only Premier parts should be used for maintenance and repair. Substitution with non-Premier parts will void the product warranty and could compromise the unit's integrity, leading to property damage, serious injury, or death.
Torque Verification: The 351 Bolts must be loosened before any adjustment of the 321B Bolt for hinge stiffness and then retorqued to 80 ft-lbs after adjustment.

Premier 330 - Page 8

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