BAKFlip MX4 (GEN 3) Hard Folding Tonneau Cover

What this cover is

The BAKFlip MX4 is a four-panel hard folding cover. The panels are aluminum with a high-density polymer core between the skins, finished in textured matte black, and they sit flush with the bed rails when the cover is closed. Gen 3 is the current revision: stiffer panels than the original MX4, reworked latches, redesigned perimeter seals, an extended tailgate seal on most applications, and a click-in rail system that goes together faster than the version it replaced.

Folding is the mainstream choice for a reason. The cover opens in stages — fold one panel for a quick reach into the back of the bed, fold the lot forward against the cab when you need the bed open — and the panels are rigid enough to sit on the closed cover without the drum-skin flex a soft cover has.

How it works day to day

Drop the tailgate, release the rear latch and fold the panels forward. Prop rods hold the stack upright against the cab and you can drive that way, with the third brake light still visible over the top. Folded flat and latched, the panels lock automatically as they go down — there is no separate key for the cover.

Security, as with almost every folding cover, comes from your tailgate. The cover latches to the rails from underneath and is reached through the tailgate opening, so a locked tailgate means a locked bed and an unlocked one does not. The tailgate itself still works normally with the cover closed; you do not have to lift a panel to open it.

Worth knowing before you order

• Folded, it costs you bed space. The stack sits at the bulkhead and stands roughly a foot proud of the rails. On a 5'7" bed that is a meaningful share of the floor, and anything you carry has to clear the stack. If you regularly need the full bed opening unobstructed, a roll-up suits you better.
• Water resistance, not waterproofing. EPDM seals around the perimeter and drain tubes at the front corners send water out through the bed drains. Heavy sustained rain, a car wash wand aimed at the seams, or blocked drain tubes will still let some through. Check the drain tubes twice a year — a plugged tube is the cause of most "my cover leaks" calls we take.
• The 400 lb figure is an evenly spread static load. Snow, a canoe lying flat, camp gear. Not a standing platform, not a mount for a rooftop tent, and not a point load.
• Over-the-rail bedliners conflict with the rails. A liner that laps over the top of the bed rail needs trimming or replacing with an under-rail liner. Spray-in liners are fine.
• Rails occupy the bed rail top. Stake pockets stay accessible, but clamp-over-the-rail racks and some bed rail caps will not coexist with the cover rails.

Fitment and installation

The MX4 is built per bed, so the correct part depends on your year, make, model and bed length. Start from shop by truck, or measure first with our bed measuring guide if you are not sure which bed you have. We check every order against your vehicle by hand before it ships and back it with our fitment guarantee.

Installation is clamp-on with no drilling on the great majority of trucks. Set the rails, clamp them, click the cover in, adjust the tension. Half an hour to an hour is realistic for a first-timer working alone. Current manufacturer instruction sheets are on our installation guides page, and if you get stuck mid-install, call us — we would rather talk you through it than have you force something.

Specifications

• Brand: BAK Industries
• Type: Hard folding tonneau cover, four panels
• Material: Aluminum panels with a high-density polymer core; aluminum rails and frame
• Finish: Textured matte black
• Load rating: 400 lb, evenly distributed
• Sealing: EPDM perimeter seals, integrated drainage, extended tailgate seal on most applications
• Latching: Automatic on close; secured by the tailgate lock
• Driving folded: Yes, propped against the cab, brake light unobstructed
• Installation: Clamp-on, no drilling on most applications
• Warranty: 5-year limited

Where it sits in the BAKFlip range

Against the rest of the line, the MX4 is the volume seller and the sensible default. The G2 is the value option with plain aluminum panels, a lower load rating and a shorter warranty. The F1 and FiberMax swap the aluminum top skin for fiberglass-reinforced polymer, which looks smoother and resists dings differently, at more money. If you want the whole bed opening clear when the cover is open rather than a stack at the bulkhead, look at a roll-up such as the Revolver X4s instead. Browse the full range under tonneau covers, or talk it through with us — this is a decision worth five minutes on the phone.

Warranty and returns

BAK covers the MX4 with a 5-year limited warranty against defects in materials and workmanship, to the original purchaser, with proof of purchase. Accident damage, misuse, improper installation, modification and normal wear are excluded, and shipping charges can apply to warranty service. Our warranty policy covers how we file a claim for you; the return window is in our returns policy.

California Proposition 65

WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.