CURT 13615 Class 3 Trailer Hitch Instruction Manual

1. Introduction

This manual provides detailed instructions for the proper installation, operation, and maintenance of your CURT 13615 Class 3 Trailer Hitch. This hitch is designed for select models of Lexus NX250, NX350, NX350h, NX450h+, and Toyota RAV4 and Venza. Please read all instructions carefully before proceeding with installation or use.

The CURT 13615 Class 3 Trailer Hitch features a 2-inch x 2-inch receiver tube, offering versatile towing options. It is rated for a maximum Gross Trailer Weight (GTW) of 4,500 lbs and a Tongue Weight (TW) of 675 lbs. When used with a weight distribution hitch, the capacity is also 4,500 lbs. WD and 675 lbs. WDTW. Always ensure that the lowest-rated towing component is not exceeded.

2. Features and Benefits

• Dependable Strength: Rated for 4,500 lbs. gross trailer weight, 675 lbs. tongue weight, 4,500 lbs. weight distribution capacity, and 675 lbs. weight distribution tongue weight (limited to lowest-rated towing component).
• Versatile Design: Equipped with a standard 2-inch x 2-inch hitch receiver, compatible with various towing accessories such as ball mounts, cargo carriers, and bike racks.
• Fully Tested: Every CURT Class 3 trailer hitch design undergoes real-world, on-vehicle testing at our Detroit engineering facility, adhering to SAE J684 standards for safety.
• Rust, Chip, UV-Resistant: Protected with a unique dual-coat finish of rust-resistant liquid A-coat and highly durable black powder coat, co-cured for exceptional resistance.
• Easy to Install: Offers a custom, factory fit on select model years of the Toyota RAV4, Lexus NX250, NX350, NX350h, and NX450h+.

Image: The CURT 13615 Class 3 Trailer Hitch, showcasing its robust design and 2-inch receiver.

3. Specifications

4. What's in the Box

• CURT 13615 Class 3 Trailer Hitch
• Installation Hardware (bolts, nuts, washers, fishwire tool if applicable)
• Instruction Sheet

5. Setup and Installation

Installation of the CURT 13615 trailer hitch is designed for a custom, factory fit on compatible vehicles. While specific steps may vary by vehicle model, the general techniques outlined below are common for many CURT hitch installations. Always refer to the detailed instruction sheet included with your product for vehicle-specific guidance.

5.1 General Installation Techniques

The following video demonstrates common techniques used during trailer hitch installation, including weldnut cleaning, fishwiring, lowering the exhaust, and frame drilling. These techniques may be necessary depending on your vehicle and the condition of its frame.

5.1.1 Weldnut Cleaning

Over time, vehicle frame weldnuts can accumulate rust, underbody coating, and debris, making it difficult to thread bolts. For minimal rust, use a wire brush and penetrating lubricant (e.g., PB Blaster) to clean the nut. For severe rust, a thread tap matching the hardware specifications may be required. Ensure the tap is perpendicular to the weldnut to prevent cross-threading.

5.1.2 Fishwiring Hardware

If there are no accessible weldnuts, hardware may need to be pulled through the vehicle's frame rail using a fishwire tool. CURT provides a fishwire tool for this purpose. There are two main techniques: standard fishwiring (inserting the coiled end up through the mounting hole and out an access hole, then attaching the spacer and bolt) and reverse fishwiring (threading the carriage bolt onto the fishwire, placing the bolt into the mounting hole head first, then feeding the spacer onto the fishwire and angling it into the mounting hole).

5.1.3 Lowering Exhaust

Some installations require lowering the vehicle's exhaust system to provide adequate clearance for hitch placement. This typically involves separating the rubber isolator from the exhaust hanger rod. Lubricate the isolator with soapy water or a penetrating lubricant for easier removal. Always support the exhaust system with a wire hanger or ratchet strap to prevent it from hanging freely and causing damage.

5.1.4 Frame Drilling (If Required)

Most CURT hitches do not require drilling. However, if additional mounting holes are needed, use the hitch as a template to mark the required locations. Drill a starter hole with a small bit, then gradually increase the bit size until the desired hole size is reached. For hard steel frames, a cobalt drill bit with coolant or grease is recommended to prevent overheating. A step drill can also be used to gradually enlarge holes. If an access hole needs to be enlarged to fit carriage bolts, a die grinder can be used to slightly elongate the hole.

5.2 Product Components

Image: Close-up view of the standard 2-inch x 2-inch hitch receiver, ready for various towing accessories.

Image: Illustration of the dual-coat finishing process, showing the liquid A-coat application for enhanced rust resistance.

Image: A CURT hitch undergoing rigorous testing in an engineering facility to ensure compliance with SAE J684 standards.

Image: Compatibility note for bike racks, showing that standard and tray-style bike racks are compatible, while vertical hanging racks are not recommended.

6. Operating Instructions

Before each towing trip, perform a thorough inspection of your trailer hitch and all towing components. Ensure all bolts are tightened to the specified torque values and that the hitch is free from damage or excessive wear. Always connect safety chains according to local regulations and ensure proper lighting connections are made.

• Weight Capacity: Never exceed the lowest-rated towing component, whether it's the vehicle's towing capacity, the hitch's capacity, or the trailer's capacity.
• Load Distribution: Distribute the trailer load evenly, with approximately 10-15% of the total trailer weight on the tongue for conventional trailers.
• Driving Safely: Drive at reduced speeds, allow for increased braking distances, and make wider turns when towing.
• Regular Checks: Periodically check the hitch, ball mount, and trailer connections during long trips.

7. Maintenance

To ensure the longevity and safe operation of your CURT trailer hitch, regular maintenance is essential:

• Inspect Regularly: Before each use, inspect the hitch for any signs of rust, cracks, bends, or other damage. Check all fasteners for tightness.
• Clean: Keep the hitch receiver free of dirt, debris, and moisture. Clean with mild soap and water, then dry thoroughly.
• Lubricate: Apply a thin coat of grease or rust-inhibiting spray to the inside of the receiver tube and any moving parts to prevent corrosion and ensure smooth operation.
• Protect Finish: The dual-coat finish provides excellent protection. If any chips or scratches occur, touch them up with appropriate paint to prevent rust.

8. Troubleshooting

• Difficulty Installing Bolts: If bolts do not thread easily, clean the weld nuts thoroughly using a wire brush and penetrating oil, or a thread tap if necessary (refer to Section 5.1.1).
• Hitch Not Fitting: Double-check vehicle compatibility and ensure all obstructions (e.g., exhaust, underbody panels) have been properly addressed as per the installation instructions. Some applications may require minor trimming of the fascia (refer to Section 5.1.4 for general frame drilling/enlarging techniques).
• Excessive Noise During Towing: Ensure all connections are secure and properly torqued. Check for worn or loose components in the hitch, ball mount, or trailer.
• Trailer Sway: This can be caused by improper load distribution or insufficient tongue weight. Adjust the trailer load to achieve the recommended 10-15% tongue weight. Consider using a weight distribution hitch or sway control device.

9. Warranty and Support

CURT stands behind the quality of its trailer hitches. The CURT 13615 Class 3 Trailer Hitch is backed by a Limited Lifetime Warranty. For specific warranty details, claims, or technical support, please refer to the documentation included with your product or visit the official CURT website.

For additional assistance or inquiries, please visit the CURT Manufacturing website.