How do I replace the Terminal House (CAM) in my Harvey Double Hung window?

Tools Required:

• Jamb Spreader (available at Harvey Building Products)
• 1/2" Flat Head Screw Driver
• Angled Pick or Angled Screw Driver
• Plastic or Rubber Mallet
• Pliers

*You may click on the images for a larger view.

Terminal House Replacement
Step 1: Open window 6" and tilt sash in until it is at a 90° angle or flat and level like a table top
Step 2: Remove the sash at this point by pulling up, you need to disengage the pivot bars from the u-shaped terminal housings or cam that it is sitting into in the frame.
After removing the sash from the window
Step 3: Unhook the balance string from the terminal housing by pulling its cord down with a pair of needle nose pliers. Be careful not to immediately let go of cord and hold it very securely. This cord is part of the balance system and you will find it has a lot of resistance. If you let go of the cord to quickly it could cause damage to the window or yourself. Instead, while holding onto the cord firmly slide it up slowly until it has fully retracted into balance casing.
Step 4: Insert the jamb spreader into the jamb with groove facing outside under the terminal housing.
Step 5: Insert your 1/2" flat head screw driver into u-shaped metal cam and turn a 1/4" to release break and free the terminal housing.
Step 6: Slide terminal housing and jamb spreader up closer to the center of the window frame.
Step 7: Now insert your flat head screw driver in between the jamb spreader and twist 90°.
Step 8: Use an angled pick or screw driver to remove broken terminal housing by angling outward.
Step 9: Maintain jamb spreader in position with screw driver, insert the new terminal house kitty-corner (angled inward), and tap in with mallet.
Step 10: Insert flat head screw driver back into terminal house and move to operating position by twisting 90° back to the left, this is the locked position (cam/terminal housing will be open at the top, ready to receive sash pivot bar).
Step 11: Re-attach balance by pulling down balance clip in terminal house with pliers.
Step 12: Re-install sash.
**CAUTION: You may want to remove the screen or put in top storage position when working on bottom sash incase you slip with the screwdriver. Also in cold weather, vinyl is less pliable so you may want to use a heat gun to warm vinyl jamb slightly or wait until the springtime.