Product Description
U-Bolt Mounting Bracket Kit for Rack Boxes & Cross-Packs
Secure Your Rack Box or Cross-Pack Directly to the Truck Frame with a Complete U-Bolt Mounting Kit — Made in the USA by AMERICAN TRUCKBOXES ATB®
These heavy-duty U-Bolt Mount Kits are designed for truckers, contractors, and fleet operators who need a dependable way to install Rack Boxes, Cross-Packs, and Crossover Toolboxes on a C-frame truck chassis.
Four heavy-duty U-bolts and matching U-clamp brackets secure the toolbox directly to the truck frame rail, helping keep the rack or box firmly in place through rough terrain, demanding job sites, and highway miles.
Manufactured by American Truckboxes LLC in Blanchard, North Dakota, each mounting kit is built to the same high standards as the company's AMERICAN TRUCKBOXES ATB® toolbox line.
Two standard center-to-center mounting configurations are available to match your rack box footprint, with custom sizing available for fleet and special-order applications.
Key Features
- Complete mounting hardware — Four U-bolts, four U-clamp brackets, washers, nuts, mounting cross, and rubber isolators included.
- Frame-ready design — Designed for a 14-inch to 20-inch C-Fame Height.
- Two U-bolt options — Available in 5/8-inch or 3/4-inch bolt diameters.
- Two mounting spacings — 4-5/8-inch CC for 5/8-inch U-bolts or 4-3/4-inch CC for 3/4-inch U-bolts.
- Rubber isolators — Help cushion the mounting points and reduce metal-to-metal contact and vibration.
- C-frame installation — Designed specifically for mounting rack boxes and crossover toolboxes to a truck's C-frame rail.
- Installation instructions included — Each kit includes an installation sheet, with the complete installation catalog available from AMERICAN TRUCKBOXES.
- Corrosion-resistant hardware — Built for demanding daily use in work-truck environments.
- Custom sizing available — Contact American Truckboxes for custom configurations and fleet orders.
Specifications
| Specification | Details |
|---|---|
| Bolt Size | 5/8 in. or 3/4 in. |
| Center-to-Center Spacing | 4-5/8 in. or 4-3/4 in. |
| Inner Depth (ID) | 14 in. to 20 in. |
| Mounting Application | C-frame Top Rail Installation |
| Weight | 15–28 lb. |
| Warranty | 60-month limited warranty. |
Kit M3460C is used with M3460-250-52B Bracket Combined.
Made in the USA
For more than 25 years, American Truckboxes LLC has manufactured truck toolboxes and mounting hardware in the USA. Every standard mounting kit is manufactured in Blanchard, North Dakota, with an emphasis on strength, durability, and dependable performance.
For custom sizing, fleet orders, or assistance selecting the correct mounting kit, call (888) 996-0376 or visit truckbox.com.
Frequently Asked Questions
Where is this mount kit made?
This U-bolt mount kit is Made in the USA by American Truckboxes LLC in Blanchard, North Dakota. American Truckboxes has manufactured truck toolboxes and mounting hardware for more than 25 years.
What warranty comes with this mount kit?
Standard mount kits carry a 60-month (5-year) limited warranty. Warranty coverage applies to the original purchaser and is non-transferable. Contact American Truckboxes for complete warranty details.
Can I order a custom size?
Yes. Custom sizing and designs are available for mount kit. Contact American Truckboxes with your Toolbox dimensions to discuss a custom configuration.
How do I know which U-bolt size I need
U-bolt height should be truck frame height plus rack or toolbox mount bracket height plus mounting plate plus nut and washer plus 1-inch.
The standard configurations are:
- 5/8-inch bolt — 4-5/8-inch center-to-center spacing
- 3/4-inch bolt — 4-3/4-inch center-to-center spacing
Check your toolbox mounting specifications before ordering, or contact American Truckboxes at (888) 996-0376 for assistance.
What is included in the kit?
Each kit includes:
- Four U-bolts
- Four U-clamp clamp brackets
- Washers
- Nuts
- Rubber isolators
- Installation sheet
What are thess mount kits used for?
This kits are designed to mount an rack box toolbox or crossover toolbox to a truck's C-frame top rail application using U-bolts and U-clamp brackets.
Does the mount kit include installation instructions?
Yes. Every kit includes a printed installation sheet. The complete installation catalog is also available from American Truckboxes for additional installation reference.
Need Help Selecting the Right Kit?
American Truckboxes LLC
Made in the USA — Blanchard, North Dakota
Call: (888) 996-0376 Web: truckbox.com
Contact us for custom sizing, fleet orders, mounting questions, or help matching a U-bolt mounting kit to your rack or box.