Repairing a Stiff Casement Window Crank

Lead Image for Repairing a Stiff Casement Window Crank
  • 1 hours
  • Beginner
  • 10-20
What You'll Need
Household oil
Small wire brush
Cleaning solvent

A casement window crank is a mechanism that is used to open a casement window from right to left or from left to right. A casement window is usually found as part of a bay window or is nestled over a kitchen sink. The crank uses some sort of ratcheting or friction mechanism to allow the window to remain open when desired. Sometimes you have problems with the crank sticking, making it difficult or impossible to open the window properly. Below are some simple steps for repairing a stiff casement window crank.

Remove the Arm

The casement window crank works by way of an arm moving the window in and out. Open the window to remove the arm. It should be a fairly simple procedure. Depending on how the crank is made, it may be necessary to remove some screws holding it in place.

Remove the Assembly

Now you can remove the assembly that is attached to your window. Start with any mounting screws that you see. Some may be hidden and you might have to remove a cover to access them. In the event that your mechanism is attached by nails, you will need to carefully pry the assembly away from the window.

Cleaning the Assembly

This assembly is what does the work in opening and closing your window. If it has become dirty it will stick. Use a small wire brush and some cleaning solvent and clean away any dirt you see. Move the mechanism back and forth occasionally while cleaning to dislodge any grit which may be lodged inside. A toothpick might be handy for reaching areas that are deeper, but be careful not to break the toothpick off into the mechanism.

If you find your mechanism is now working smoother than it did before, you are successful. Oil the mechanism with a simple household machine or you can purchase specialized items at your home improvement store. Move the mechanism back and forth, allowing the oil to reach all moving parts. You are ready to replace it when it moves smoothly

Clean the Frame

On the bottom of the frame or the stop is a track on which the mechanism glides. This too may have become caked with dirt or debris. Use your wire brush and solvent and clean this off as well. Apply some grease to this area after it is clean

Reinstall the Parts

Following the reverse order of the way you took off the parts, replace all the parts, screwing in all screws tightly. Check the operation of the crank. It should now move the window open smoothly. Wipe away any grease or oil that might've spilled.


If this does not work, your only other option is to completely replace the crank mechanism