Casement Window Crank Replacement — Operators, Hinges and Locks
The crank turns and nothing happens, or the sash opens but will not come back far enough for the lock to catch. The window is fine. The hardware is worn, and it can be replaced.
Casement window crank replacement fixes a casement that spins free, grinds, will not open, or will not pull shut enough to lock. JMB Builders does it across the Twin Cities metro: we read the brand and series off the sash label or the glass, match the operator, hinge arms, keeper or sash lock, order the parts, and install and adjust them so the sash closes tight and locks. Priced per window, quoted from your photos within one business day.
- Priced per window; parts ordered from the label
- Operators, hinge arms, keepers and locks for common brands
- Sash adjusted so it seals and locks after the swap
- Quote from photos in 1 business day
- Licensed MN contractor BC809005
A casement window has a handful of moving parts and they wear out long before the window does. The operator is the crank gearbox; when the teeth strip, the handle spins and the sash does not move, or it grinds and stalls partway. The operator arm rides in a track on the bottom of the sash, and the shoe that runs in that track cracks or pops out. The hinge arms at the top and bottom carry the sash, and when they wear or the screws loosen the sash sags and drags on the frame. The keeper and the lock handle pull the sash tight; when they are bent or worn, the window closes but never seals and the lock will not throw.
None of that means a new window. Every major casement maker has sold replacement operators and hardware for decades, and the parts for the common series are still available if you know exactly what you have. That is the part homeowners get stuck on. The right operator depends on the brand, the series, the year, whether it is a single-arm or dual-arm unit, and which hand it is. Order the wrong one and it does not fit the holes or the track.
We sort that out from your photos. The label on the sash edge, the etched code in the corner of the glass, or the stamp on the old operator tells us what to order, and we source it through the manufacturer's parts line or a window parts supplier. On the day, the interior stop or cover comes off, the old operator and arms come out, the new hardware goes in with the sash supported, and the hinges and keeper are adjusted so the sash closes square, compresses the weatherstrip and locks with normal effort. The trim goes back on and the window works like it did when it was new.
What you supply
- A photo of the whole window from inside, and a close-up of the crank and the arm where it meets the bottom of the sash
- A photo of the label on the edge of the sash when it is open, or of the etched code in the corner of the glass
- A description of what it does: spins free, grinds, stuck open, stuck closed, or closes but will not lock
- The number of windows with the problem; several on one visit cost less each
- A hardware finish preference if the old one is no longer made, since we will match as close as the maker offers
What JMB supplies
- Identification of the brand, series and handing from the label, glass code or old operator
- The replacement operator, operator arm and track shoe, hinge arms, keeper or sash lock, ordered before the visit
- Interior cover or stop removed and reinstalled without damage to the casing
- Sash supported and hinges adjusted so it does not sag or drag on the frame
- Keeper and lock aligned so the sash pulls tight against the weatherstrip and locks with normal effort
- Old hardware removed and screw holes plugged where the new pattern differs
- Lubrication of the hinge tracks and check of the weatherstrip while the sash is open
- Photos of the finished window in your job folder
How it is priced: per window
Quoted in writing from your photos within one business day. What moves the number:
- Operator only vs. operator plus hinge arms, keeper or lock
- Single-arm vs. dual-arm operator, and whether the maker still stocks that series
- A discontinued series that needs a retrofit operator and new mounting holes
- Sash that has sagged and needs hinge adjustment or new hinge arms to close square
- Number of windows fixed on the same visit
- Special-order hardware finish vs. the standard white or stone
The sash label photo is the one that matters. With it we can price the exact part before we come out; without it we may need a short visit to identify the hardware first.
How long it takes
Parts usually take one to two weeks to arrive. The swap itself is about an hour per window once we are there, less when several windows take the same operator.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
Operator replacement
The crank spins or grinds and the sash does not move. We match the operator by brand, series, arm type and handing, swap it, and set the arm shoe back in the sash track. The most common casement repair.
Hinge arms and sash adjustment
The sash sags, drags on the frame, or the top corner hits before the bottom closes. Worn hinge arms or loose hinge screws are the cause. New arms, the hinge channel cleaned, and the sash adjusted so it closes square.
Keeper and sash lock
The window closes but the lock will not throw, or it locks and still leaks air. The keeper on the frame or the lock handle on the sash is worn or bent. Replaced and aligned so the sash compresses the weatherstrip when locked.
Discontinued hardware
The maker no longer sells the exact operator. We fit a retrofit operator that matches the arm and track, plug the old screw holes and drill new ones, and cover the base plate. The window works; the handle may not match the others exactly.
Casement Window Crank Replacement — Operators, Hinges and Locks: questions, answered
Why does my casement window crank spin but the window does not open?
The gears inside the operator have stripped, or the operator arm has come out of its track on the bottom of the sash. If the handle turns with no resistance at all, it is the gears and the operator needs to be replaced. If it turns and you can hear something moving but the sash stays put, the arm shoe has popped out of the track and can sometimes be reset without new parts.
Can a casement window operator be replaced without replacing the window?
Yes. The operator is a bolt-on part behind the interior cover, and every major casement maker has sold replacement operators for their series for many years. We identify the exact part from the label on the sash or the code in the glass, order it, and swap it in about an hour. The window itself, the glass and the frame stay.
How do I find out what brand my casement window is?
Open the sash and look at the edge of the sash or the top of the frame for a printed or stamped label with the maker and a series or order number. If there is no label, look in a corner of the glass between the panes for etched letters and numbers; that code identifies the maker and often the year. Send a photo of either one and we take it from there.
Why will my casement window not close all the way?
Three common reasons. The sash has sagged on worn hinge arms so a corner hits the frame first. The operator arm is bent or its track shoe is broken so it cannot pull the sash in the last inch. Or the keeper is out of line with the lock so the sash stops short. We check all three on the visit and replace or adjust what is worn so the sash pulls in tight and locks.
Can you replace the crank handle only?
Yes, if the operator itself is sound and only the handle is broken or missing. Handles are brand-specific and come in the maker's finishes. Folding handles that tuck under a blind are also available for most series. If the handle turns but the window does not move, the problem is inside the operator and a new handle will not fix it.
Do you fix double-hung windows that will not stay open too?
Yes, that is a balance replacement rather than an operator, and we do it the same way: identify the window, order the balances, swap them. It is a different repair from a casement crank. For a house with a mix of windows we can do both on one visit and price per window.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners and for the builders and dealers we sub for. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
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Read morePage reviewed September 27, 2026 · JMB Builders LLC, MN license BC809005 · All window trim pages
Where we work
Window trim near you
Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: