If your vinyl tilt window is hard to open, won’t stay up, or slams shut, the balances are often the problem. The good news: installing Jambliner balances into Jambliners is straightforward once you know the correct orientation and how the locking tab works.

What You’re Installing (Quick Definitions)

• Jambliner (vinyl jamb liner): The vinyl track that mounts inside the window jamb and guides the sash.
  
  

• Jambliner balance: The spring-loaded metal balance that slides into the Jambliner and provides lift support for the sash.
  
  

• Balance shoe (plastic end piece): The plastic “foot” on the end of the balance that interfaces with the track and helps it seat/lock properly.
  
  

Tools & materials:

• Flathead screwdriver (used to help seat/lock the balance)
  
  

• The correct Jambliner balance(s) for the window
  
  

• Matching Jambliner(s)
  

Helpful (optional):

• Workbench or padded surface
  
  

• Gloves + eye protection (balances are spring-loaded)
  
  

Before You Start: 3 Things That Prevent 90% of Problems

1. Confirm you have the right balance length/strength. (Mismatched balances cause poor sash operation.)
   
   

2. Check the balance shoe orientation before inserting. The shoe must face the correct way to ride the track.
   
   

3. Locate the locking/tab area near the Jambliner end. You’ll use a screwdriver here to guide the balance into its final seated position.

Step-by-Step: Install Jambliner Balances into Jambliners

Step 1: Identify the “end” of the Jambliner you’ll load from

On the end you’re loading from, you’ll see the open channel where the balance slides in. This is the end where you’ll start insertion. Be sure to also remove the jambliner brackets if there are any.

Tip: Keep the Jambliner steady on a bench edge so you can push the balance straight in without twisting.

Step 2: Inspect the balance shoe and set the correct orientation

Hold the balance so you can clearly see the plastic shoe on the end.

• Make sure the shoe is fully attached and seated on the balance end.
  
  

• Align the shoe so it will slide smoothly into the Jambliner track (don’t force it if it feels “crossed up”).
  
  

Rule of thumb: If the shoe doesn’t want to enter the channel smoothly, it’s usually rotated the wrong way.

Step 3: Start the balance into the Jambliner channel

Insert the shoe end first into the Jambliner opening and begin sliding the balance into the track.

• Keep the balance square to the Jambliner.
  
  

• Push it in steadily—no bending or angling.

Step 4: Slide the balance in until it reaches the end/stop area

Continue feeding the balance inward until you reach resistance near the Jambliner end—this is typically where the locking tab/stop needs to be guided past or seated.

At this point, it’s normal to feel like the balance is “almost there.”

Step 5: Use a flathead screwdriver to seat/lock the balance

With the balance nearly fully inserted, use a flathead screwdriver at the Jambliner end to:

• gently depress or guide the small metal tab/clip, and/or
  
  

• help the balance edge snap into its seated position.
  
  

You’re not prying hard—you’re guiding the balance past the final catch so it sits correctly.

What “correct” looks like: the balance is fully home in the channel, and the end/tab area sits flush and controlled (not half-cocked or springing outward).

Step 6: Verify the balance is seated and aligned in the track

Do a quick visual check down the Jambliner:

• The balance should run straight inside the channel.
  
  

• The end hardware should be positioned consistently (not sticking out at a weird angle).
  
  

• Nothing should bind when you lightly move/confirm the balance position.
  
  

If the balance looks slightly “hung up,” repeat Step 5 and re-seat it.

Step 7: Repeat for the second Jambliner (if applicable)

Most windows use a left and right Jambliner, each with its own balance.

Install the second balance the same way, paying attention to:

• shoe orientation
  
  

• end/locking tab seating

Common Mistakes (and Quick Fixes)

Mistake: The balance won’t slide in more than an inch or two
✅ Fix: Re-check shoe orientation and make sure you’re in the correct channel.

Mistake: Balance goes in but won’t seat at the end
✅ Fix: Use the flathead screwdriver to gently guide/depress the locking tab area until it seats.

Mistake: Balance looks twisted inside the Jambliner
✅ Fix: Remove and reinsert while keeping the balance straight and square to the track.

Mistake: Window still won’t stay up after installation
✅ Fix: You may have the wrong strength/length balance, or the sash engagement point isn’t correct.

FAQ: Jambliner Balance Installation

Do I need special tools?
No—most installs only require a flathead screwdriver to help seat the balance near the end.

Which end goes in first?
Insert the shoe end first so the plastic shoe rides the track properly.

How do I know it’s locked in?
It will sit fully in place near the end/stop area and won’t look partially backed out or misaligned.

View Our Video on How to Install Jambliner Balances Here!

For more information or assistance ordering new jambliners, Contact Us Today! The WHD Team is here to help.