A stripped window crank isn’t the end of the world, but it certainly qualifies as a frustrating problem to have. Luckily, you don’t need to be a window expert or veteran handyman to fix this minor annoyance. Fixing a stripped window crank doesn’t require many tools or advanced technical know-how, but it does call for some patience and preparation. It’s a problem you’ll want to address as soon as possible so you can open and close your window with ease, maintain proper ventilation in your home, and prevent unnecessary strain on the rest of the window hardware.

A stripped crank can manifest in different ways. Sometimes the gears inside the crank mechanism wear down, making it difficult or impossible to grip and turn the window open or closed. Other times, the splines inside the handle—those ridged grooves that fit over the crank’s shaft—become smoothed out or broken, resulting in a handle that spins uselessly. Both situations fall under the “stripped” category and require replacing the faulty part to restore proper function.

Match the Window Parts

It’s tempting to dive right into this project and remove the old window crank right away, but before you do, set yourself up for success by tracking down the exact replacement parts you’ll need. After you remove the old stripped window crank, you’ll want to have a new one ready to install immediately so your window isn’t left unusable for days or weeks.

Finding a new crank can be straightforward if you have newer windows, as many big-box hardware stores carry standard replacement parts. However, if your windows are older or discontinued, the task can become a little more challenging. Start by checking the manufacturer’s name or model number on the existing crank—this is often stamped somewhere on the housing. With that information, you can search online for exact matches or compatible substitutes. Specialty hardware suppliers and online marketplaces carry a wide range of hard-to-find parts, and even if your exact model is no longer produced, you may be able to locate a universal-fit crank that works with your setup.

Home improvement stores like Home Depot or Lowe’s may also have generic window cranks that can be adapted to fit. Bringing your old crank (or detailed photos with measurements) to the store can help you compare dimensions, gear types, and handle styles to ensure a proper match.

Once you have the new window crank and any accompanying hardware—such as screws, the operator mechanism, or handle—on hand, you can proceed with the repair knowing you won’t be stuck mid-project without the right parts.

Remove the Original Crank

Because the original crank is stripped, you may need a screwdriver, pry bar, or drill to remove it. Begin by checking how the crank is secured to the windowsill and frame. Most are attached with a few screws through the flange plate. If these screws are rusted or stripped themselves, take care when removing them so you don’t damage the surrounding wood or hardware.

Before you remove the crank entirely, you’ll need to open the window. Since the mechanism is damaged, you might have to assist it manually. Turn the crank’s knob while gently pushing on the window sash until it moves. Position the window so that the crank arm’s inner wheel aligns with the center notch on the track—this is the release point.

Push down on the arm to pop the inner wheel out of the track. Next, remove the window casement trim. This trim board sits over the crank’s flange and is typically secured with nails or screws. Using a screwdriver, pry bar, or small crowbar, gently lift it free to avoid damaging the wood or surrounding finish.

Once the trim is off, unscrew the flange from the windowsill. Keep an eye out for any washers, spacers, or other small components—these may need to be reused if your new crank doesn’t come with replacements. If the crank handle spins without moving the window, the internal gears are likely stripped. In that case, replacing the entire operator mechanism is usually the best solution. If only the handle’s splines are damaged, you might get away with replacing just the handle itself.

Install the Replacement Parts

With the old crank removed, you can now install the new parts. Use either a screwdriver or drill to attach the replacement crank, aligning the flange’s screw holes with the existing holes in the sill. This ensures a snug fit without having to drill new holes, which could weaken the surrounding material.

Next, line up the wheel on the new crank arm with the middle notch in the track. Push the wheel into the track until it clicks or seats fully. Test the crank handle by opening and closing the window several times to confirm smooth operation. If it binds or resists movement, double-check the alignment and mounting screws before proceeding.

Once you’re satisfied with the fit and function, secure the crank fully. Replace the casement trim board over the flange, fastening it with new finishing nails or screws for a clean, secure finish. If the trim was damaged during removal, this is a good opportunity to repair, repaint, or replace it.

A New Window Crank

Replacing a stripped window crank is a relatively simple home repair that can be completed in under an hour with just a few basic tools. The most challenging step is often sourcing the exact replacement part, especially for older windows. Taking time to find the correct match before starting ensures the process goes smoothly from start to finish.

Once installed, a new crank should provide years of smooth, reliable operation. Regularly cleaning and lightly lubricating the crank mechanism can help extend its life, prevent premature wear, and keep your windows easy to operate.

Feldco is the most trusted company for window replacement with over 500,000 delighted customers across the Midwest. Whether you need a simple hardware fix or a full window replacement, we make the process easy and stress-free. Get a free quote now and restore both the function and beauty of your home’s windows.