How to Replace Your Milgard Ultra Series Sash Lock

These instructions will guide you through how to replace the sash lock on your Milgard Ultra Series window.

Safety Precautions:  Activities in this video are appropriate for individuals with an understanding of how to use simple hand tool. Remember to wear eye protection and make sure that pets and small children are not present when performing these activities.  Questions? Call 1-800-Milgard or visit

You’ll need a number 2 phillips head screwdriver, a new Ultra Series sash lock, and a putty knife.  Let’s begin by removing the bottom sash.  Push the lock all the way open and pull the sash inward.  Be careful not to over-rotate the thumb lever.  While holding the sash perpendicular to the floor, carefully remove the sash by lifting one side up to disengage the pivot pin.  Once both sides are disengaged, remove the sash from the frame.  Remove the lock cover using a flat putty knife.  Use a number 2 phillips screwdriver to remove the screws on the interior operator lock.  Once the screws are taken out, remove the old sash lock.  Locate the lock gear on the new sash lock.  Locate the nylon tension strap on the top of the window sash in the aluminum casing.  Install the new sash lock by inserting it into the sash making sure the nylon tension strap fits into the slot on the lock operator gear.  Re-install the screws.  Replace the lock cover with the handle turned to the right.  Operate the lock to make sure the side lock guides work.  Re-install the sash into the window frame.