Repair and replacement · Rolling Shutter Guide
How do I replace or re-spool a rolling shutter crank box?
First try cranking slowly the other way; most crank shutters that won't move with an intact strap are being cranked the wrong way. To replace the box, crank the strap out, unclamp it from the metal band, swap the box below the diamond roller, re-clamp the strap and crank clockwise. Never open the crank box.
Key facts
- When a crank shutter's strap is not broken, Roll-A-Shield's service desk finds the handle is being turned the wrong way about 90% of the time. Roll-A-Shield data
- Do not open the crank box; it can damage the parts inside. The strap is changed at the metal band at the top of the box. Roll-A-Shield data
- A crank box mounts directly below the diamond roller at about waist height with four fasteners, with about 3 ft of strap below it. Roll-A-Shield data
- Roll-A-Shield builds every crank shutter with the same crank-box part on either side; the control side is set by where the strap leaves the shutter box. Roll-A-Shield data
- On Roll-A-Shield crank boxes, turning the handle clockwise (the arrow on the case) raises the shutter. Roll-A-Shield data
Applies to: Strap-and-crank rolling shutters with a wall-mounted crank box (strap winder), including Roll-A-Shield's. Not crank-wand or manual-override motors, which use a wand on the shutter box.
A crank box is the wall-mounted box inside the room that winds the shutter's strap in and out as you turn the handle. The strap runs from the shutter, through the wall and the diamond roller, down into the box, where its end is clamped under a metal band. Most crank problems are not a broken box, so check the cheap causes before you buy one.
Following a published Roll-A-Shield guide does not void the warranty. Mains wiring must be done by a licensed electrician.
Is it really the crank box?
Usually not. When the strap is intact, Roll-A-Shield's service desk finds the handle is being turned the wrong way about 90% of the time. Work down this table before replacing anything.
| Symptom | Likely cause | Fix |
|---|---|---|
| Strap snapped or frayed | Worn strap | Replace the strap |
| Crank turns but the shutter will not go up | Cranking the wrong way | Turn slowly the other way; follow the arrow on the box |
| Handle spins, shutter does not move, strap intact | Strap has come off the spool inside the box | Re-spool it (see below) |
| Strap pulls loose from the box | Strap not clamped on the metal band | Re-clamp the band over the strap |
| Strap twists or rubs | Box not directly below the diamond roller | Re-mount the box straight below the roller |
| Handle loose or not turning smoothly | Handle not attached securely | Seat the handle firmly in the square opening and check it turns smoothly |
| Shutter sticks partway in the rails | Obstruction in the rails | Clear the rails; the box is not the problem |
| Mechanism broken or box damaged | Failed crank box | Replace the box |
For the step-by-step version of these checks, see Why won't my manual shutter move?
What does re-spooling mean, and can I do it?
Re-spooling means getting the strap wound back onto the spool inside the crank box after it has come off. It can happen when the handle is turned the wrong way, and the usual sign is a handle that spins while the shutter does not move.
Stop: Do not open the crank box. Roll-A-Shield's install manual says not to open it, to avoid damaging the parts inside. Roll-A-Shield has a service video showing the re-spooling technique; call (480) 921-0200 and the team will send it to you. If the strap still will not wind after that, replace the box.
Is there a left-hand and a right-hand crank box?
No, not on Roll-A-Shield shutters. The factory fits the same crank-box part whichever side the crank is on. The side is decided by the shutter: the control side is the side where the strap leaves the back of the shutter box, and the crank box goes on the wall directly below the diamond roller on that side. So you order a crank box, not a left or right one. If your shutter is another make and the old box looks handed, send a photo before you order.
The direction does not change with the side either: on Roll-A-Shield crank boxes, the arrow on the case points clockwise, and clockwise raises the shutter.
What do I need to replace the box?
- A replacement crank box (Roll-A-Shield sells them in the parts store)
- The crank handle, or a new crank handle
- Flathead and Phillips screwdrivers
- A pencil, a drill and four fasteners suited to your wall
A failed crank box is replaced as a complete unit.
How do I replace the crank box?
Lower the shutter fully first, so the curtain is resting on the sill.
- Holding the strap, slowly crank the strap out of the box until you feel it reach its end.
- Tug the strap up to expose the metal band at its end, bend the band back and slide the strap off.
- Unscrew the old box from the wall.
- Make sure the strap hangs straight down from the diamond roller, not off to the side, which wears it quickly.
- Hold the new box directly below the strap and diamond roller at about waist height, mark the four holes and fix it with four fasteners.
- If you are fitting new strap, cut it so about 3 ft hangs below the box and cut a 1/2 in vertical slit about 1 in from the end, folding the strap to cut the slit in the center. An intact old strap already has its slit; reuse it.
- Straighten the metal band on the new box and slide the slit onto it. Turn the strap 90 degrees so it lies along the band, then fold the band down over the strap.
- Push the crank handle into the square opening at the bottom right of the box.
- Turn the handle slowly clockwise, the way the arrow on the case points, guiding the band and strap past the entrance rollers at the top of the box. Keep turning until the shutter begins to rise.
- Raise and lower the shutter a few times. Clockwise raises; counter-clockwise lowers.
Tip: Before you clamp the band, check the strap runs straight and untwisted from the diamond roller all the way down into the box. A straight strap winds cleanly.
Can I swap a crank box for a pull-strap box, or the other way round?
Both boxes mount in the same place, directly below the diamond roller at waist height, but a crank box takes four fasteners and about 3 ft of strap below it, while a pull-strap box takes two fasteners and about 1 ft. Going from a pull-strap box to a crank box therefore usually needs new strap. Call (480) 921-0200 to confirm the change suits your shutter; the pull-strap version is covered in How do I replace a pull-strap box?
What next
Crank boxes, crank handles, strap and diamond rollers are in the Roll-A-Shield parts store. In metro Phoenix, Roll-A-Shield's service team services rolling shutters of any make.
Watch it done
Service tutorial: replacing a crank box
The written steps on this page are the reference; the video shows the same job.
Frequently asked questions
Is there a left-hand and a right-hand crank box?
Not on Roll-A-Shield shutters: the factory fits the same crank-box part whichever side the crank is on. The side is set by where the strap leaves the shutter box, and the wall box goes directly below the diamond roller on that side.
Can I take the crank box apart and rewind it?
No. Roll-A-Shield's install manual says not to open the crank box, to avoid damaging the parts inside. If the handle spins and the shutter does not move, the strap may have come off the spool inside; ask for the re-spooling video at (480) 921-0200.
Which way do I turn the crank to raise the shutter?
Follow the arrow on the crank box. On Roll-A-Shield crank boxes that is clockwise to raise and counter-clockwise to lower.
Do I need a new strap with a new crank box?
Not if the old strap is sound: the new box clamps onto the same strap end. If the strap is frayed, replace it at the same time and leave about 3 ft below the box.
Parts and next step
Need a part or a hand?
Crank boxes, crank handles and strap are in the Roll-A-Shield parts store. For anything else, call (480) 921-0200 with a photo of your box. Call (480) 921-0200; the factory answers technical questions for any rolling shutter, not only ours.