Westin EXP Truck Cap Review: 2020-2023 Jeep Gladiator JT

The Westin EXP Truck Cap turns the 2020-2023 Jeep Gladiator JT into a lockable, weather-sealed mini-SUV without a single drilled hole. Built from 5-piece extruded aluminum with gullwing side doors, integrated roof rails, and a 300 lb dynamic load rating, it sits between a basic tonneau and a fiberglass camper shell — tougher than the soft tops, lighter than the shells, and far cheaper than either if you buy the right kit. At NLP Performance in Tampa, this Gladiator JT cap has been one of our most-viewed bed accessories this month, so we built this guide to answer the questions we keep getting: which box ships when, what the actual install looks like on a 5-foot bed, and whether the sliding front glass upgrade is worth the extra $345.

What Is the Westin EXP Truck Cap?

The Westin EXP Truck Cap is an aluminum bed topper designed to replace a tonneau cover with something closer to a camper shell — but lighter, modular, and street-legal in every state without a permit. For the 2020-2023 Jeep Gladiator JT it covers the entire 5-foot bed, locks via twin T-handle gullwing doors plus an auto-unlocking rear hatch, and turns the bed into dry, secure storage you can stand cargo up inside of without having to slide it around a low-profile tonneau.

Mechanically it is a 5-piece extruded aluminum shell: one roof panel, two gullwing side panels, a fixed front panel, and a top-hinged rear door. The panels are bolted together with stainless hardware, sealed at every joint with EPDM sponge gasket, and the entire assembly clamps onto the JT's factory bed rails using Westin's included aluminum clamp kit. No drilling, no permanent modification, and the cap pulls off in roughly the reverse of the install if you ever need the open bed back.

Key Specs at a Glance

Westin publishes specifications that buyers actually care about — load ratings, install time, and warranty — rather than burying them in a downloadable PDF. Here are the numbers for the JT-fit EXP cap:

The 700 lb static load number is what carries a rooftop tent (most run 130-180 lb) and two adult sleepers (320-400 lb combined). The 300 lb dynamic limit is what carries kayaks, lumber, or a Yakima rack full of gear at highway speed without flexing the roof panel. For comparison, most plastic tonneaus list 200-400 lb static and have no published dynamic rating because they are not designed for it. The EXP gives you a real load rating because it is structurally an aluminum shell, not a stretched vinyl panel.

Why the EXP Ships in Two Boxes (and Why That Matters)

This is the single most-asked question we get on the phone: "I see Box 1 ONLY in the title — what am I missing?" The answer is that Westin splits the EXP into two freight cartons because no single carrier accepts a 6-foot-tall single-piece aluminum shell on a standard LTL pallet. Box 1 contains the roof and front panel. Box 2 contains both gullwing side panels, the rear door, all hardware, the lock harness, and the rubber bed strip. You need both boxes to mount the cap.

At NLP, we list the boxes individually because some customers buying replacements after a shipping freight claim only need one. But for a fresh install on a 2020-2023 Gladiator JT, the right move is the bundled Complete Kit, which ships both boxes from the same warehouse on the same BOL. That saves the second freight charge and guarantees the boxes arrive together — no waiting on Box 2 while a half-assembled cap sits in your garage.

Which Kit Should You Buy? Side-by-Side Comparison

For most JT owners, the decision comes down to two kits: the standard Complete Kit A + BS, or the same cap with the sliding front glass upgrade. The two "ONLY" SKUs exist for replacement and warranty scenarios — not for fresh installs.

Pros and Cons After Real-World Use

Our Tampa, FL customers run these caps through Florida humidity, Gulf Coast salt spray, and the occasional Everglades trail trip. After three seasons of shop feedback and warranty claims, here is what consistently comes up:

Installation: What Actually Happens in the Driveway

Westin rates the install at Skill Level 2 and quotes 1-2 hours. In our Tampa shop, an experienced installer averages 90 minutes with a helper. Solo installs are possible but slower because the gullwing side panels weigh roughly 45 lb each and need to be held vertical while you start the joining bolts.

The install sequence is straightforward: clamp the included aluminum rail extrusions to the JT's factory bed rails, set the roof panel on top, bolt the front panel in, then attach the two gullwing sides one at a time. The rear door hangs from a top-mounted hinge that the kit pre-assembles. The lock harness routes through the existing dome-light wire pass-through so no new holes are drilled into the body. Total tools needed: a 10mm socket, a 13mm socket, a Phillips screwdriver, and a torque wrench for the bed-rail clamps.

One install tip we share with every customer: do not fully torque the clamp bolts until all five panels are joined. The aluminum extrusion has roughly 1/8 inch of slip in the clamp before tightening, and using that slip to square the cap on the bed makes the door alignment perfect on the first try. We have seen DIY installs where the customer torqued the clamps first and ended up with a rear door that needed shimming to close.

Compatible Accessories Worth Adding

The EXP cap is built to accept Westin's accessory ecosystem and most third-party rooftop hardware. If you are spending the money on the cap, these are the add-ons that earn their place:

The EXP LED Strip Harness ($54.99) is the lowest-effort upgrade — it taps into the JT's reverse light or interior dome circuit so the cap interior lights up when you open the rear door or hit the unlock fob. The Gladiator Clamp Bed and Cover Kit ($154.99) is required if you are running an aftermarket bed liner that sits proud of the factory rails — it gives the clamps a flat surface to bite. The Cover Corner Kit ($92.99) seals the front corners against the cab when you run the cap with a soft tonneau-style filler.

If you want better visibility for spotting trail obstacles from inside the cap, the EXP Rear Window in Smoke ($919.99) swaps the standard rear panel for a tinted glass window. It is a Box 2-equivalent part, so you cannot just bolt it onto an existing AS + BS cap — you order it instead of the standard sides at purchase.

Westin EXP vs Bestop Supertop for Truck 2

The honest comparison every Gladiator owner makes is the EXP versus the Bestop Supertop for Truck 2 — the soft top alternative. The two products solve the same problem (covering a JT bed) very differently, and the right answer depends on how you actually use the bed.

The Bestop Supertop for Truck 2 ($1,049.99 for Black Diamond, $1,549.99 for Premium Black Twill) is a fabric-and-bow assembly that mimics the look of the JT's factory soft top. The bows fold forward to expose the entire bed in about a minute, the side windows unzip for ventilation, and the entire assembly comes off the truck in roughly 15 minutes if you ever need a clean bed. It is the right answer if you want a removable cover that looks OEM and you are not worried about lockable cargo security.

The Westin EXP Truck Cap ($3,449.99 for the Complete Kit) is structurally an aluminum shell. It does not fold, it does not unzip, and removing it takes both people and 30-45 minutes. In exchange you get T-handle lockable doors, an auto-unlock rear hatch, a 700 lb static load rating that takes a rooftop tent, and weather sealing that genuinely keeps out Florida thunderstorms. It is the right answer if the bed is going to carry expensive cargo, sleeping gear, or anything you do not want a smash-and-grab attacker to see.

Cost-wise the EXP is roughly 2-3x the Supertop. Function-wise it is closer to a fiberglass camper shell at half the weight and a fraction of the install effort. Customers who pick the Supertop tend to be daily-driver Gladiator owners who keep the bed empty most of the time. Customers who pick the EXP tend to be overlanders, contractors, and anyone whose bed regularly carries tools, camping gear, or rooftop tents.

Frequently Asked Questions