How to Replace a Stripped Casement Window Crank: A Step-by-Step DIY Guide

Updated at: 24/03/2025

Frustrated with a broken casement window crank? A stripped crank handle can make opening and closing your windows a real hassle, leaving you feeling stuck in a stuffy room or vulnerable to drafts. Fortunately, replacing a stripped casement window crank is a manageable DIY project that can save you the expense of calling a professional. This common problem often stems from years of wear and tear, or perhaps a little too much force applied during operation. Don't let a simple broken part ruin your comfort and peace of mind.

This guide provides a straightforward, step-by-step approach to replacing your faulty crank, empowering you to tackle this repair with confidence. Whether you're a seasoned DIY enthusiast or a complete beginner, we'll walk you through each stage, ensuring a smooth and successful replacement. Let's get started with the detailed instructions below.

Preparation and Safety Guidelines

Tools Needed
  • Utility knife
  • Flat bar
  • Hammer
  • Phillips/flathead screwdriver or screw gun
  • Flat screwdriver
  • Finish nails
  • Painter's caulk
Safety Guidelines
  • Always disconnect the power to the window operator before starting any work to prevent electric shock. If unsure, turn off the breaker supplying power to the circuit the window is on.
  • Wear safety glasses to protect your eyes from debris or sharp edges that might occur during the process of removing and installing the parts.
  • If you are uncomfortable performing this repair yourself, contact a qualified window repair professional. Attempting a repair beyond your skill level could lead to further damage or injury.

Step-by-Step Instructions

  1. Prepare the Window

    • Remove the window screen.
    • Unlock the window lock and open the window slightly.
    • Remove the handle using a screwdriver.
    Remove the handle using a screwdriver.Remove the handle using a screwdriver.Remove the handle using a screwdriver.
    Prepare the Window

  2. Remove the Trim

    • Cut along the trim where it meets the window frame using a utility knife. Cut the bottom and both sides.
    • Carefully remove the trim using a flat bar and hammer.
    • Remove any nails holding the trim in place.
    Remove any nails holding the trim in place.Remove any nails holding the trim in place.Remove any nails holding the trim in place.
    Remove the Trim

  3. Disconnect the Crank

    • Use a flat screwdriver to slide back the clip and disconnect the crank arm.
    • Remove the screws holding the window crank to the sill.
    • Remove the old window crank.
    Remove the old window crank.Remove the old window crank.Remove the old window crank.
    Disconnect the Crank

  4. Install the New Crank

    • Install the new window crank using the same screws and holes.
    Install the new window crank using the same screws and holes.
    Install the New Crank

  5. Reconnect and Secure

    • Reattach the crank arm and secure the pin.
    • Use finish nails to secure the bottom trim. If using the Philip screw style, screw those back in.
    • Apply painter's caulk to seal the edges of the trim.
    Apply painter's caulk to seal the edges of the trim.Apply painter's caulk to seal the edges of the trim.
    Reconnect and Secure

  6. Final Steps

    • Reinstall the handle, ensuring it's in the down position when the window is closed.
    • Reinstall the window screen.
    Reinstall the window screen.Reinstall the window screen.
    Final Steps

Read more: 3M Thinsulate Window Film Installation: A Step-by-Step Guide

Tips

  • There are two styles of molding attachment: nailed and spring-loaded with flip screws. Remove flip screws before removing trim if applicable.
  • Some screws might be located under the window crank arm; move the crank to access them.
  • Use a hammer to tap the pin all the way in to ensure proper seating.

Common Mistakes to Avoid

1. Stripping the replacement crank's screw hole

Reason: Using excessive force or an incorrectly sized screwdriver when attaching the new crank can easily strip the screw hole, rendering the new crank unusable.
Solution: Use the correct size screwdriver and apply even pressure; if resistance is high, stop and reassess your technique.

2. Forgetting to secure the window before removing the old crank

Reason: The window may shift or fall unexpectedly while removing the old crank, leading to potential damage or injury.
Solution: Always secure the window in a closed or partially closed position using a suitable latch or support before starting the repair.

FAQs

What if I can't find an exact replacement crank for my window?
While finding an exact match is ideal, many casement window cranks are interchangeable. Measure the length of your existing crank's spindle (the part that inserts into the window mechanism) and look for a replacement with a similar spindle length and compatible end shape. Hardware stores often have a selection of universal cranks; if unsure, bring your old crank for comparison.