The Weather Guard 391-5-02 delivers high capacity and a blacked-out look on an 8' bed. This wide-body Super Hi-Side stretches 90" and runs 16-1/4" wide by 18" tall for a big 15.2ft³, welded aluminum diamond plate under a tough black ARMOR TUF coat that hides grime and fights corrosion. It rides high on one rail of an 8' bed so the floor stays open, 42" doors load long gear, and it weighs far less than a steel box this size.
What's Included:
391 Super Hi-Side aluminum diamond plate Hi-Side truck tool box, black
Two side-opening doors with tool-less QuickClip hinges
Two drill-resistant locking T-handle latches with three-point latching
Under-rail mounting brackets and hardware for a no-drill install
Removable parts bin
Full-perimeter weather seal with rain gutter, pre-installed
Weather Guard installation instructions
Features
Lightweight Aluminum Diamond Plate The 391-5-02 is formed from welded aluminum diamond plate, so it adds locking storage without the weight penalty of steel. Aluminum naturally resists rust and corrosion, which keeps the box working and looking good through road salt and wet weather.
Black ARMOR TUF Finish A black ARMOR TUF powder coat covers the aluminum diamond plate to fight scratches, fading and corrosion and give your truck a blacked-out diamond-plate look. ARMOR TUF is Weather Guard's toughest coating, built to hold up to sun, chemicals and the weather.
Twin Locking Doors, Drill-Resistant Locks Two side-opening doors each use a drill-resistant lock core and a three-point latching system to resist break-ins, so gear on both ends of the box stays secure. The doors open wide for easy reach into the full 15.2ft³ interior.
Tool-Less QuickClip Doors The doors adjust from 90 to 180 degrees and pop off with QuickClips, no tools required, so you can fully remove a door for loading and clip it back on in seconds. It makes packing long or bulky gear far easier.
Rain Gutter and Full Weather Seal A rain gutter design paired with a full-perimeter weather seal keeps rain, dust and debris out of the box and off your tools. Your gear stays dry and ready in wet weather and on dusty jobsites.
Rides High, Frees Your Bed Floor The Hi-Side design mounts on top of one bed side rail and stands up along the bedside, so your tools ride up and out of the way and the bed floor stays open for sheet goods, lumber and cargo. A removable parts bin keeps small items organized up top.
Removable Parts Bin and a Wide Door Opening Each door on the 391-5-02 opens to a clear 14-3/4" high by 42" wide opening, which is enough to slide long hand tools and cases straight in from the side of the bed. A removable parts bin rides inside for fasteners, fittings and the small parts that otherwise end up loose in the bottom, and it lifts out when you need the full length of the box.
Fit guidance: Hi-Side and Super-Side boxes mount on top of one bed side rail and stand up along the bedside, so the box rides above the wheel well and keeps the bed floor open. This box is 90-1/4" long, so it requires a full-size 8' long bed. It can mount on the driver or passenger side rail. Always measure your bed rail length and check cab and bedside clearance before ordering, and note it is not designed for mid-size or compact trucks.
Specifications
Series: 391 Series Super Hi-Side
Style: 18" top-mount side-rail box, twin side doors
Storage Capacity: 15.2ft³
Exterior Dimensions: 90-1/4"L x 16-1/4"W x 18"H
Door Opening (each side): 14-3/4" high x 42" wide
Material: Welded aluminum diamond plate
Finish: Black ARMOR TUF powder coat
Doors: Two side-opening doors, tool-less QuickClip hinges, 90 to 180 degrees
Latching: Drill-resistant lock core, three-point latching, each door
Weather Seal: Rain gutter with full-perimeter weather seal
Mounting: Mounts on top of one bed side rail, under-rail brackets and hardware included, no drilling required
Shipping Size: 90-7/8"L x 17-1/4"W x 18-3/8"H, 85.5 lb
UPC: 783965038560
Weight: About 86 lb (83 lb shipping)
Warranty: Limited Lifetime
Made In: USA
Installation
Type: Top-of-rail side mount, clamp-in with no drilling · Time: About 30 to 45 minutes · Tools: Socket or wrench set and a tape measure; no drill needed with the included under-rail brackets · Difficulty: Easy to moderate, best done with two people because of the 90" length and weight
Set the box on top of one bed side rail and position it front to back, then hook the included brackets under the rail lip and tighten the hardware evenly so the box sits flat and the doors seal. Because the box is 90" long, have a second person help lift and steady it while you clamp it down. Follow the Weather Guard Hi-Side and Super-Side installation instructions for exact bracket placement and torque.
Watch the installation walkthrough:
Resources
Everything you need for your Weather Guard 391 Super Hi-Side Truck Tool Box, 90" Black Aluminum, in one place.
Warranty. Limited Lifetime Warranty from Weather Guard against defects in materials and workmanship.
Free shipping. This item ships free to the lower 48 states. Because it is an oversized item, it ships by freight and typically arrives in 3 to 7 business days.
Inspect on delivery. Please inspect the packaging before signing. If you see any damage, note it on the delivery receipt and contact us right away, and we will make it right.
About Weather Guard
Weather Guard has built professional-grade truck and van storage in the USA for decades and is the storage brand tradespeople, contractors, and fleets reach for first. Its steel and aluminum tool boxes, ladder racks, and van-interior systems are engineered to survive daily jobsite abuse and keep expensive tools secure and organized.
Known for weather-tight seals, patented locking systems, and heavy-gauge construction, Weather Guard products mount cleanly on work trucks and vans and stand up to years of hard use. The lineup spans crossover, low-side, and saddle truck boxes, ladder and van racks, drawer units, and fuel and utility tanks, so an entire work vehicle can be outfitted from one brand.
Backed by a strong manufacturer warranty and US-based support, Weather Guard is the name pros trust to protect the tools their livelihood depends on.
Authorized Weather Guard dealer. Prestige Truck is an authorized dealer of Weather Guard, so every tool box, rack and storage product you buy is 100% genuine and factory-new, covered by the full Weather Guard manufacturer warranty, and backed by our own US-based support team.
Compare The Range
How this compares to similar models
The closest alternatives side by side, so you do not have to keep tabs open.
Model
This OneWeather Guard 391 Super Hi-Side Truck Tool Box, 90 in Black Aluminum (391-5-02)
Weather Guard's official step-by-step guide to pulling and replacing a box door, filmed on a high-side box. Weather Guard publishes it on this box's own product page, so keep it bookmarked in case a door ever needs to come off for service or gets damaged on the job.
Weather Guard Truck Box Lineup and 1Key UltraLock
This official Weather Guard overview tours the current truck box lineup and the 1Key UltraLock security system that runs across it. You see how one coded key can open every Weather Guard box on the truck, from saddle to lo-side to hi-side, with a pop-up red button that tells you at a glance whether a box is locked. It highlights the sloped, reinforced lids and the ARMOR TUF powder coat that let these boxes shrug off weather and jobsite abuse. If you run more than one box, or a whole fleet, it shows why keying everything alike saves time every day.
Best Upgrade for Your Truck
This is Weather Guard's own brand film about outfitting a working pickup, built on the idea that the truck should already be loaded and organized before the day starts. It puts the bed and rail equipment in the context of a real work day rather than a spec sheet.
Watch it if you are still deciding how much storage a truck actually needs. It is the clearest short look at how Weather Guard boxes, racks and drawer units are meant to work together on one vehicle, and it comes straight from the manufacturer rather than a reseller.
Frequently Asked Questions
Straight answers on specs, fit and support
Will the 391-5-02 fit my truck?
The 391-5-02 is 90-1/4" long and requires a full-size 8' long bed. As a taller, wider Super Hi-Side, check cab and side clearance along with rail length before ordering. It mounts on either side rail and is not designed for mid-size or compact trucks.
Does it require drilling to install?
No. The box ships with under-rail brackets and hardware, so it clamps to the top of your bed side rail without drilling. Most installs take about 30 to 45 minutes and go easiest with two people to lift and hold the 90" box while you tighten the hardware.
How much does it weigh and is it strong?
It is built from welded aluminum diamond plate and weighs only about 83 lb shipping, far lighter than a comparable steel box, which saves payload and makes it easier to mount. Aluminum also naturally resists rust, so it holds up to road salt and wet weather while staying secure with drill-resistant locks.
What is the black finish like?
The aluminum diamond plate wears a glossy black ARMOR TUF powder coat for a rugged, blacked-out look, and the aluminum resists corrosion underneath. It hides grime a bit better than a bright finish and cleans up with mild soap and water.
How secure is it and how do the doors work?
The roomy 15.2ft³ interior opens through two side doors, each 42" wide by 14-3/4" tall, so tall cases and bulky power tools load easily. Every door has a drill-resistant lock core with three-point latching, swings 90 to 180 degrees, and pops off on tool-less QuickClips. The gloss black coat gives a finished, blacked-out look.
Is it made in the USA and under warranty?
Yes. The 391-5-02 is made in the USA and backed by a Weather Guard Limited Lifetime Warranty against defects in materials and workmanship.
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