Next Level Performance
October 4, 2026 • 9 min read
Our Verdict
For winter bed storage on a 2020-2024 Silverado/Sierra 2500/3500 HD, the UnderCover SwingCase beats a bulky universal tool box: it is lockable, weatherproof, installs in about 20 minutes with no drilling, and swings your gear out to you instead of making you climb into a snow-filled bed.
Run one per side ($219.99 each) for roughly 3 cu ft of secure, salt-proof storage while keeping the full bed floor open. Need more raw volume? A Lund aluminum or steel box is the budget-volume alternative — both are on Clearance right now.
Shop Our Top Pick →Winter bed storage for a 2020-2024 Chevy Silverado 2500/3500 HD (and its GMC Sierra 2500/3500 HD twin) comes down to a simple choice: a dedicated, vehicle-specific UnderCover SwingCase or a big universal truck tool box. The SwingCase is a lockable, weatherproof storage box that mounts along one bed rail, swings out to you on a pivot, and keeps your recovery gear out of the cab and off the salted road. In this comparison we put the SwingCase head-to-head with two Lund universal boxes so you can see exactly which winter bed-storage setup fits your heavy-duty truck, your gear, and your budget.
At our Tampa, FL shop we fit these on HD trucks headed north for ski season and plow work all winter. The pattern is consistent: owners want a dry, lockable home for a recovery strap, traction boards, a jump pack, gloves, and chains — without giving up the open bed they bought the HD for. That is the whole reason the SwingCase exists, and it is why we reach for it first on a 2500/3500 HD before a floor-hogging chest.
What Is the UnderCover SwingCase?
The UnderCover SwingCase is a molded, lockable storage box that bolts to one inside bed rail of your truck and swings out on a pivot when you pull the release lever. It is built from lightweight, high-impact ABS plastic, is fully weatherproof, and is custom-fitted per truck — one SKU for the driver side (SC105D) and one for the passenger side (SC105P) on the 2020-2024 Silverado/Sierra 2500/3500 HD. Each case holds 1.5 cu ft and up to 75 lb, weighs about 20 lb empty, and installs with a no-drill clamp bracket in roughly 20 minutes per side.
Because it tucks against the bed side ahead of the wheel well, the SwingCase leaves the entire bed floor open for a pallet, a sled, or firewood — a real advantage over a chest that eats the front of the bed. UnderCover’s own pitch sums up the value: you can buy two SwingCases for less than the price of an old-fashioned truck bed box, and still keep the space.
The SwingCase pivots out on its release lever so gear comes to you — no climbing into a snowy bed.
UnderCover SwingCase — Key Specifications
Closed and locked, the SwingCase keeps winter gear dry, secure, and out of the cab.
The Universal Box Alternative: Lund Aluminum vs Steel
If you haul more than a recovery kit — think power tools, chains for a whole crew, or job-site equipment — a universal truck box gives you far more volume for the money. Lund’s aluminum underbody box mounts under the bed or frame rail and keeps the bed floor completely clear, while the steel job-site chest is a security-first box that stores in the bed or the garage. Both are on Clearance at NLP Performance right now, which makes them aggressive on price-per-cubic-foot.
The trade-off is winter-specific. The Lund aluminum box is brite diamond-tread aluminum, so it shrugs off road salt and never rusts — the right pick if your box lives in the spray. The steel chest is enormous and pry-resistant with a self-enclosed hinge, but bare steel needs care in a salt environment and the chest is heavy. Neither is vehicle-specific, so you must confirm clearance and mounting on your 2500/3500 HD before you buy.
Lund’s brite aluminum underbody box resists road salt and keeps the full bed floor clear.
The Lund steel job-site chest trades bed space for huge, pry-resistant volume.
SwingCase vs Universal Box: Winter Storage Compared
Here is the head-to-head for a 2020-2024 Silverado/Sierra 2500/3500 HD. The SwingCase wins on fit, finish, and ease of access; the Lund boxes win on raw volume per dollar. Prices shown are live at NLP Performance.
| Kit | Storage | Material | Install | Price |
|---|---|---|---|---|
| UnderCover SwingCase – DriverTop Pick | 1.5 cu ft | High-impact ABS | No-drill, ~20 min | $219.99 |
| UnderCover SwingCase – Passenger | 1.5 cu ft | High-impact ABS | No-drill, ~20 min | $219.99 |
| Lund Aluminum Underbody Box | ~8.4 cu ft | Brite aluminum | Under-rail bolt-on | $395.58 |
| Lund Steel Job Site Chest | ~18 cu ft | 16-ga steel | In-bed / garage | $588.73 |
Run SC105D and SC105P together for about 3 cu ft of locked, dry storage on both bed rails.
UnderCover SwingCase: Pros and Cons
What We Like
- + No-drill clamp mount installs in about 20 minutes per side
- + Weatherproof, rust-proof ABS — ideal for salt and slush
- + Swings out to you — no climbing into a snow-filled bed
- + Lockable and keeps the full bed floor open
Things to Consider
- – 1.5 cu ft per case is modest — add the second side for ~3 cu ft
- – Vehicle-specific: SC105D/SC105P fit the HD truck only, not transferable
Universal Lund Boxes: Pros and Cons
What We Like
- + Far more volume: ~8.4 cu ft (aluminum) up to ~18 cu ft (steel)
- + Aluminum is rust-proof and the steel chest is highly pry-resistant
- + Both are on Clearance — strong price-per-cubic-foot
Things to Consider
- – Universal fit — verify clearance and mounting on your HD truck
- – Bare steel needs care in road salt; the chest is heavy and bulky
How to Keep Winter Bed Storage Working in the Cold
Any lockable box can freeze shut in a Florida cold snap or a northern deep freeze if moisture gets into the mechanism. In our shop we prep every winter install the same way: wipe the SwingCase’s weathertight seal clean, hit the keyed twist-lock with a dry PTFE or graphite lubricant (not a wet oil that attracts grit), and keep the case’s drain path clear so meltwater runs out instead of refreezing around the latch. For the Lund boxes, the same graphite-on-the-lock rule applies, and the aluminum box’s stainless T-handle is the one you want when the truck lives in salt.
Pack smart, too: a dry recovery kit — strap or kinetic rope, traction boards, gloves, and a jump pack — belongs in the box, not loose in the cab where it ends up under the back seat. Keeping that gear sealed, locked, and off the salted bed floor is the entire point of a winter storage upgrade.
Frequently Asked Questions
What is the best bed storage for a 2020-2024 Silverado 2500 HD in winter?
The UnderCover SwingCase is the best winter bed storage for a 2020-2024 Silverado 2500/3500 HD. It is a lockable, weatherproof ABS box that mounts to one bed rail, holds 1.5 cu ft and 75 lb per side, installs in about 20 minutes with no drilling, and keeps your recovery gear dry, secure, and off the salted bed floor while leaving the full bed open.
Will the UnderCover SwingCase fit a GMC Sierra 2500/3500 HD?
Yes. The same SwingCase SKUs fit both trucks — SC105D (driver) and SC105P (passenger) are listed for the 2020-2025 Chevrolet Silverado 2500/3500 HD and GMC Sierra 2500/3500 HD, which share the T1XX heavy-duty platform and identical bed rails.
Does the UnderCover SwingCase require drilling?
No. The SwingCase mounts with a no-drill clamp bracket that grips the bed rail, so there are no holes in your truck. A typical install takes about 20 minutes per side with hand tools, and the case lifts off its hinge if you want to remove it.
How much can a SwingCase hold?
Each SwingCase holds 1.5 cu ft of gear and is rated to 75 lb. Running both the driver (SC105D) and passenger (SC105P) cases gives you roughly 3 cu ft of locked, weatherproof storage — enough for a recovery strap, traction boards, a jump pack, gloves, and chains.
SwingCase vs a universal truck tool box: which is better for winter?
For most HD trucks the SwingCase is better for winter because it is vehicle-specific, lockable, rust-proof ABS, and leaves the bed floor open. A universal Lund box wins only when you need raw volume — about 8.4 cu ft in the aluminum underbody box or roughly 18 cu ft in the steel chest — and you are willing to verify fitment and give up bed space.
Will the lock freeze in winter?
A lock freezes only when moisture collects in it. Treat the SwingCase’s keyed twist-lock with a dry PTFE or graphite lubricant, keep the drain path clear so meltwater escapes, and the latch stays free in the cold. The same graphite-on-the-lock step keeps the Lund boxes working all winter.
Can I run a SwingCase on both sides of the bed?
Yes. UnderCover makes a mirrored pair — SC105D for the driver side and SC105P for the passenger side. Many HD owners run both for about 3 cu ft of total storage, and the pair still costs less than one old-fashioned bed chest.
Does a steel truck box rust from road salt?
Bare steel can corrode in road salt if the finish is chipped, so it needs occasional care. If your box lives in winter spray, brite aluminum (the Lund underbody box) or the SwingCase’s ABS plastic is the smarter, rust-proof choice.
Winterize Your Truck Bed
Lock down your winter gear with an UnderCover SwingCase or a Lund box — shop bed storage and thousands more parts at NLP Performance.
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