BAKFlip MX4 Hard Folding Tonneau Cover for 2021-2026 Ford F-150 / F-150 Lightning (5'7" Bed)

Here's the short version. Follow BAK's install sheet (below) for your truck's exact clamp positions and settings.

1. Clean and seal. Every spot where the cover mounts must be clean. If your kit includes a bulkhead seal, clean the top of the bulkhead with soap and water, then isopropyl alcohol, let it dry and stick the seal from one edge of the bulkhead to the other, trimming the excess. A truck with a drop-in bed liner doesn't need the seal.
2. Set the side rails. If your kit includes rubber filler strips, stick them between the plastic bed cap and the metal rail: one 6-8" from the bulkhead, one as close to the tailgate as possible and one centered. Fit the drain tubes to the front of the side rails, then set each rail flush with the top edge of the bed rail, drain-tube end toward the cab, pushed all the way forward and square (90°) to the bed rails so the rear latch engages. Route the drain tubes behind a bed liner, through the bed plugs or through a 5/8" hole drilled in the bulkhead.
3. Clamp the rails. Use three or four clamps per side, depending on the truck: the front one 6-8" from the bulkhead, the rear one as close to the tailgate as possible and the rest evenly spaced. Push the back of each clamp up as high as it goes, keep the rail level with the bed cap, and tighten to 10 ft-lb with a 1/2" wrench or socket. Don't over-tighten; clamps tightened too fast or too hard make the rails lean.
4. Prep the cover. Slide the two cover retainer clamps into the track under the cab end of the cover, one per side. Peel the liner off each gasket, stick it under a buckle end, and screw the two buckle ends into the pre-drilled holes on the front header panel with the screws and nutserts. Hand-tighten only; don't use a screw gun.
5. Set the cover in place. Lay the folded cover on the side rails at the cab end, centered between them, and turn the retainer clamps clockwise until the lock washer is snug. With the cover still folded, clean the spots for the cab bumpers with soap and water, then isopropyl alcohol, let them dry and stick the bumpers along the top edge where the cover meets the cab.
6. Unfold, adjust and check. Unfold the cover toward the tailgate and center every panel side to side and front to back; the rear edge and tailgate seal rest on top of the tailgate with a 1/2" overlap. With a power tailgate, make sure it still works with the cover closed. Release each latch to check it engages the rails (the sheet shows how to adjust a slam latch), then re-tighten the retainer clamps. BAK's warranty asks you to re-check every clamp after your first week of driving.