Last Updated: November 12, 2026
Quick Summary
A crossover toolbox spans the front of the truck bed behind the cab, while a side mount toolbox runs along one side rail. Crossover boxes offer more storage with a single lid, while side mount boxes keep the middle of the bed open for long cargo. The right choice depends on how you use your bed.
- Crossover boxes mount across the front of the bed and hold more volume.
- Side mount boxes run along one rail and keep the bed center clear.
- Measure your bed length before choosing a crossover toolbox.
- Check tonneau cover clearance against the box height before buying.
- Choose a side mount box if you regularly haul long lumber or pipe.
Table of Contents
- Crossover vs Side Mount Toolbox: The Short Answer for Common Truck Uses
- How Crossover and Side Mount Toolboxes Differ in Design and Placement
- Truck Bed Toolbox Sizes and Usable Bed Space Tradeoffs
- Tonneau Cover Compatibility, Rear Visibility and Bed Access
- Choosing the Right Toolbox for Your Bed Size and Cargo, Plus What to Check Before You Buy
- Booking Your Toolbox Decision: Shop the Right Fit on Truck Army
- Frequently Asked Questions
Crossover vs Side Mount Toolbox: The Short Answer for Common Truck Uses
A crossover toolbox spans the front of the truck bed behind the cab, while a side mount toolbox runs along one side rail. For most work trucks that haul tools daily, a crossover box gives you more storage and a single lid to manage. For trucks that carry long cargo, camp, or need the full bed open, a side mount box usually fits better. Which one suits you depends on how you use the bed, not on which one looks better on the truck.
Most owners find the split comes down to two questions: how much you need to store, and how much open bed you need to keep. Crossover boxes trade some bed floor for capacity. Side mount boxes keep the middle of the bed clear. Both can be paired with a tonneau cover, though the fit check matters more than most buyers expect.
How Crossover and Side Mount Toolboxes Differ in Design and Placement
The two styles look different on the truck, but the real differences show up in how they sit, how you open them, and what they leave behind. Start with placement and the rest of the decision follows.
!Pickup truck bed with an aluminum diamond-plate toolbox mounted across the front of the bed, a worker reaching into the open lid in a daylight driveway
Crossover Toolbox Design and Placement
A crossover box mounts across the front of the bed, usually behind the cab, and spans most of the bed width. To compare other ways to organize bed cargo, see bed cargo management system options. Because it runs across the bed, it can hold more volume, and most crossover models offer one or two lids.
The tradeoff is bed floor. A box across the front takes up the space where you would otherwise stack lumber or load a cooler, and it can interfere with some cargo setups. The TrailFX 140701 listing notes that drilling is required for installation, so confirm the mounting method for your specific truck before you buy.
Side Mount Toolbox Design and Placement
A side mount box runs along the bed rail on one side. It keeps tools reachable from the side of the truck while leaving the center of the bed open for long or bulky loads. The TrailFX 160721 72-inch, 160601 60-inch, and 160481 48-inch aluminum side mount boxes all fit this pattern, and each is listed with mounting hardware included and no drilling required.
Side mount boxes give up some total volume compared to a full-width crossover box, but they make the bed easier to use for ladders, pipe, or lumber. The one thing to check is that the box fits your bed rail and that nothing else you carry on that side gets blocked.
Truck Bed Toolbox Sizes and Usable Bed Space Tradeoffs
Box size drives most of the tradeoff, so compare the listed dimensions against your bed before you order.
Start with the side mount boxes. The three TrailFX side mount boxes run 48, 60, and 72 inches long, each 11-1/4 inches wide and 11 inches high. Per the listings, they offer about 3, 3.7, and 4.4 cubic feet of storage.
The crossover boxes are listed at 69 inches long and about 19-1/4 inches wide. The TrailFX 140701 is listed at 8.8 cubic feet and the 120701 at about 8.4 cubic feet, per their listings. A crossover box spans the bed width at the front, so it removes a band of floor across the front of the bed, roughly 19-1/4 inches of bed length across most of the width. That band is where long cargo would otherwise rest, so the practical effect is a shorter usable cargo length in front of the box.
Here is how to translate that into a real decision:
- Measure your bed length from the inside of the tailgate to the front wall (or bulkhead).
- For a crossover box, subtract the box's listed width (about 19-1/4 inches on these models) from that length to estimate the cargo length you keep in front of the box.
- For a side mount box, subtract the box's listed width (11-1/4 inches) from your bed width to estimate the floor width you keep beside the box, and subtract the box length from the rail length you keep for other rail-mounted gear.
- Compare those numbers to the longest and widest items you haul most often, lumber, pipe, ladders, a cooler, a motorcycle, or flat loads.
A common pattern is that a crossover box is the better fit when your cargo is short and you want maximum enclosed storage, while a side mount box is the better fit when you need the center of the bed clear for long or bulky loads.
Watch out: Measuring only the box's exterior dimensions can mislead you.
The listed dimensions for each box style show how much bed space each one takes up.
| Box | Listed length | Listed storage |
|---|---|---|
| TrailFX side mount, 48-inch | 48 in | About 3 cu ft |
| TrailFX side mount, 60-inch | 60 in | About 3.7 cu ft |
| TrailFX side mount, 72-inch | 72 in | About 4.4 cu ft |
| TrailFX 140701 crossover | 69 in | About 8.8 cu ft |
| TrailFX 120701 crossover | 69 in | About 8.4 cu ft |
Listed storage
Tonneau Cover Compatibility, Rear Visibility and Bed Access
Tonneau covers are where many toolbox decisions go sideways. Before you buy, check how the box and the cover work together, because the two styles interfere with covers in different ways.
A crossover box sits at the front of the bed, so the cover has to clear the box lid when it opens and close around the box.
A side mount box sits along the rail, which can limit how a cover folds or rolls on that side, depending on the cover design.
Rear visibility is the other factor.
Bed access is the third piece.
Watch out: Do not assume a cover and a box are compatible just because both fit your truck.
Choosing the Right Toolbox for Your Bed Size and Cargo, Plus What to Check Before You Buy
Start with what you haul most often, then work backward to the box style.
Choose a crossover toolbox if:
- You carry a lot of small tools, hardware, or jobsite gear and want the most storage.
- Your bed usually holds smaller cargo that fits around the box.
- You want one large lid and a tray for organization.
Choose a side mount toolbox if:
- You regularly haul long lumber, pipe, or ladders that need the full bed.
- You want to keep the middle of the bed open for camping or flat loads.
- You want quicker side access without climbing into the bed.
Before you buy, check these points:
- Confirm the box length against your bed length and rail layout.
- Check whether mounting requires drilling, and whether you are comfortable with that.
- Make sure the box does not conflict with your tonneau cover's listed clearance.
- Plan for how the box will be secured to keep tools and equipment protected.
- Measure how much usable bed space you will lose with each option.
Watch out: Measuring only the box's exterior dimensions can mislead you. Check the usable bed width your truck offers, then compare it to the listed box width before ordering.
Truck Army Tech Tip: Before you order, tape the box dimensions onto your bed floor and check the clearance with the lid open and closed. It takes five minutes and catches most fit problems before the box is mounted.
Booking Your Toolbox Decision: Shop the Right Fit on Truck Army
Once you know which style fits your truck and your work, the next step is picking the exact box. The TrailFX side mount options (48, 60, and 72 inches) cover a range of rail-mounted needs, while the TrailFX 140701 and 120701 crossover boxes handle larger bed-front storage. Compare the listed dimensions, storage capacity, and drilling requirements against your truck before you buy.
If you are not sure whether your truck's configuration matches a listing, check the fitment details on the product page first. Verified fitment through the vehicle garage is the fastest way to confirm a match before you order.
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Frequently Asked Questions
What is the difference between a crossover toolbox and a side-mount toolbox?
A crossover toolbox spans the full width of the truck bed behind the cab, so it sits across the bed rails. A side-mount toolbox bolts to the bed rail along one side and leaves the middle of the bed open. Crossover boxes generally hold more gear and usually take up more usable bed space, while side-mount boxes keep the bed center clear for cargo and are often easier to reach over the rail. Check the product listing for dimensions and mounting requirements before you buy, since fit depends on your specific truck.
Does a crossover toolbox take up more bed space than a side-mount toolbox?
Yes, in most cases. A crossover box sits across the bed and reduces the open floor you have for lumber, coolers or ladders. A side-mount box uses only one side of the bed, so more of the center stays available. Measure the box height, the bed rail clearance and the bed width you need for your typical cargo, because a box that looks compact on paper can still limit what fits in the bed.
Can you use a crossover toolbox with a tonneau cover?
Often, but it depends on the box and the cover. Crossover boxes sit at or near the bed rail height, so the cover mounting system and the box lid must clear each other when opened. Check the tonneau cover manufacturer's compatibility notes and confirm the toolbox height and mounting location before you order both. Side-mount boxes can also work with covers, but they are installed on the rail, so clearance still needs checking.
Which toolbox works best for a pickup that hauls daily?
For daily hauling, a crossover box usually gives more storage for tools and gear, while a side-mount box keeps the bed floor open for long or bulky loads. Think about what you haul most often and how often you need to reach the box while the bed is loaded. If you carry a lot of tools and the bed is mostly tools, a crossover box is a strong choice; if you haul sheets, pipe or wide cargo, a side-mount box is often easier to live with.
