How to replace Window Master sliding aluminum window rollers and prolong the useful life of your windows
My 40-year-old house has WindowMaster aluminum double pane windows with interior window “lites” lattices. These are excellent windows with very secure double locks. These original WindowMaster aluminum double pane windows could easily last another 40 years or more. Ten of the Window Master aluminum windows in my house are large horizontal sliding windows. There is one significant problem with them.
The two sliding rollers under each sliding window are relatively small and made with small 1/2-inch diameter grooved white nylon plastic rollers. Over the years as these Window Master aluminum windows have been slid open and closed repeatedly, these white nylon rollers have worn down to the point that they no longer roll. Instead, they get stuck in one position and wear down as my WindowMaster aluminum window are dragged back and forth along the guide bar in the bottom of the window frame.
So, you say, just replace them. Unfortunately, that is not so easy. WindowMaster is no longer an independent company and the original plastic and nylon replacement roller assemblies for original sliding WindowMaster aluminum windows simply cannot be found on the market. However, the good news is that replacements for original WindowMaster windows are still being manufactured. You can get exact replacements for Window Master aluminum windows from window wholesalers. (Note by the way that the windowmaster dot com website exists, but it has nothing to do with original WindowMaster windows.)
In 2004, Jeld-Wen, Inc. (a large Oregon-based window manufacturer with about 14,000 employees and $3 billion in annual revenue) acquired WindowMaster. WindowMaster aluminum windows are now Jeld-Wen’s Premium Aluminum Windows product line, which can be sourced from a variety of window wholesalers, including through the Home Depot special order desk. The outer pane of one of my original Window Master picture windows was broken and I was able to buy a replacement with the same design and exact dimensions as the original.
The problem for the owner of a home with original WindowMaster aluminum windows is that at some time in the past perhaps WindowMaster and definitely Jeld-Wen changed the design of these sliding window roller assemblies. So, what is the solution for the homeowner with worn down white nylon plastic rollers?
I have found three different solutions that could help your preserve the value of your original sliding WindowMaster aluminum windows. I wrote this article, because this project took time and effort. I hope that information in this article will help solve this problem much more quickly for other original WindowMaster homeowners.
Replacing original WindowMaster sliding window rollers — Solutions A, B, and C
- Solution A: Replace only the white nylon plastic rollers in the same original small plastic roller assembly
- Solution B: Replace the whole roller assembly with an off-the-shelf metal roller assembly
- Solution C: Modify the original small plastic roller assembly to accommodate durable metal rollers.
I have tried all of solutions A, B, and C, and here is how to go about each of them.
First, note that for each sliding WindowMaster aluminum window there are two small but rugged rectangular plastic roller assembly housings that are roughly 1/2 inch wide and 3/4 inch long. Each of these rugged rectangular plastic housings holds a 1/2 inch grooved white nylon plastic rollers on a metal pin axle that is about 2 mm in diameter.
To get access to these sliding WindowMaster aluminum window roller assemblies, do the following in good weather when the window can be opened.
- A) Open the window fully.
- B) Find, unscrew, and remove the security bracket found in the top of the frame (replace it later when done).
- C) Center the window in the frame and lift the window gently and pull out at the bottom to get the window out of the bottom channel
- Note that there is a protruding center metal piece attached to the fixed window that can catch near the top of the sliding window you are removing. So be careful and work around that. At the correct angle the window will not catch on that protruding center metal piece.
- Note also that if you have any window blinds attached to the top of the wooden frame to house the window, you may or may not need to first remove those window blinds before removing the sliding window itself.
- D) Turn the window upside down and place it on a towel or cardboard while leaning the window against a wall. Making sure the window will not slide across the floor, fall, and perhaps break.
- E) Now you will see the two plastics roller assemblies that can be removed with your fingers so that you can work on them over on your table top or work bench.
Preparing for Solutions A, B, and C by cutting out the rubber liner
There is one step I recommend before you do any of these three solutions below. While the sliding window is inverted and leaning against the wall note that right below the 1/2 inch by 3/4-inch metal cutout for the roller assembly in the bottom of the window, there is a rubber liner. Solutions A, B, and C will all have the roller protrude slightly down into the cutout. The white nylon roller in the original assembly also protruded down somewhat into this cutout. I believe that part of the problem with these original WindowMaster sliding aluminum window nylon rollers is that the roller can catch on this rubber lining and sometimes not roll properly. On two of the windows that I repaired, there was evidence of this.
The solution is relatively easy. Use either an Exacto knife or a box cutter with a fresh sharp razor blade. Inside the cutout in the aluminum, cut the thin rubber liner at the edges that are parallel to the window pane. Then, cut across the rubber liner perpendicular to the window pane. When you cut across, leave about 2 mm of the rubber liner on each side for the plastic housing to rest on. There is metal below this rubber liner, but you should be careful cutting anyway. After you remove the piece of liner you cut out, you may find some sticky black adhesive. Just take bits of paper towel and a flat head screw driver to scrape out the adhesive.
Summary of the pros and cons for Solutions A, B, C
Solution A below requires you to swap out the 1/2-inch nylon roller. Most homeowners can do this relatively easily with household tools. The cost is about $13 for a pair per window plus a modest shipping fee. The downside that you may need to repeat this over the years on windows that you open and close frequently.
Solution B below is the least difficult solution with the cost per window in the middle. You simply swap by hand the new metal roller assembly for the current plastic roller assembly. The cost is about $7 for a pair per window plus a modest shipping fee. Because the metal roller will protrude in the original cutout more than Solutions A and C, it is a must to cut out the rubber lining as detailed in the ‘Preparing for Solutions A, B, and C” section above. I expect that Solution B will last “forever.”
Solution C below is the least expensive solution, but requires the most time, tools, and skill to modify the original plastic assembly housing to accommodate the new metal wheel and larger diameter shaft. This is for the “Mr. Fixit” who enjoys a challenge. The cost per window is about $3. I expect that Solution C will last “forever.” The homeowner with spare time, skills, and numerous original Window Master sliding aluminum windows might prefer Solution C, but Solution B is frankly easier and not that expensive.
How to do Solution A: Replace the white nylon plastic rollers in the same original small plastic roller assembly
About ten years ago, I first encountered that problem with my WindowMaster sliding aluminum window nylon rollers wearing down. Ten years ago, I was able to purchase some 1/2 inch grooved white nylon plastic rollers as a replacement. However, after ten years of use on frequently opened and closed sliding glass windows, even these replacement rollers began to wear down and stick. Therefore, this is a solution that can require repeated replacements after some years of use.
Furthermore, recently (2026) I tried to find 1/2 inch grooved white nylon plastic rollers on the Internet and could not find them. I am a thorough researcher, so it is not likely that I missed what was available. (You could source them directly and economically from China, but they were made to order and everything needed to be specified, thus they were not “off-the-shelf.”
However, I did find that SWISCO.com has a roller assembly that you can buy and then take out the 1/2 plastic roller and swap it for the roller in the original WindowMaster sliding aluminum window nylon roller housing. You would have to swap, because plastic roller housings are not the same size.
In late 2026 this product was SWISCO.com Product Code: 87-210 Sliding Window Roller, 1/2″ Concave $6.45
https://www.swisco.com/1-2-concave/pd/Sliding-Window-Rollers-With-Plastic-Housing/87-210
For a pair of rollers, the cost was about $13 plus reasonable shipping, so I bought a pair. However, I did not use them, because I also had bought the materials for Solutions B and C below, and decided that I preferred Solutions B and C as being both cheaper and more permanent.
How to do Solution B: Replace the whole roller assembly with an off-the-shelf metal roller assembly
I carefully researched sizing and the only small ready-made metal roller assembly that I could find that seemed to have acceptable dimensions was this one, which is normally used for sliding cabinet drawers:
Product Info Length: 1-7/8 Inch, Width: 7/16 Inch, Height: 7/16 Inch, Product Finish: Gray, Includes: (1) Steel roller, See more product details
I found these for $3.04 each at cabinetparts.com and ordered two of them. The shipping fee was modest.
Since I had ordered two of these to see if they would fit, these Knape & Vogt Steel Rollers were the first I tried with the first Window Master sliding aluminum window that I worked on. After I trimmed out the rubber lining in the existing cutout for the original plastic roller assembly, I placed the KV-620-STL roller assembly and it fit almost exactly and snugly into the aluminum trough in the bottom of the window.
The KV-620-STL roller assembly has two holes for screws, and I had planned to CAREFULLY drill a hole into the bottom of the window frame and then use a short self-tapping metal screw that would be no longer than 3/8 inch long to hold the KV-620-STL roller assembly in place. (Note that you must exercise great care when drilling toward glass, since you can shatter a window with a drill bit. As I said above below the rubber lining is more metal, but being careful is the best way to avoid Mr. Fixit regret.)
However, none of this drilling was required. I found that the KV-620-STL roller assembly stayed wedged into the channel at the bottom of the WindowMaster sliding aluminum window. I turned the window right side up and carefully installed it back into its track. I made sure to lift it up as high as possible in the top track so that the new metal KV-620-STL roller assembly would stay wedged into the channel at the bottom and not be knocked out.
Once the window was resting on its roller track with the new metal roller assembly, the window rolled back and forth easily. It has been over a month and the window has been opened and closed in normal operation at least a dozen times with no problems. The new metal KV-620-STL roller assembly has stayed in place without needing to be screwed down. One factor is that the weight of the window keeps the roller assembly pressed into the track.
If I had known that the KV-620-STL roller assembly was such a quick and easy fit and could be installed without drilling and screwing, I would have ordered enough to replace the roller assemblies on all my Window Master sliding aluminum windows. However, when I was researching all potential solutions, I did not want to try one solution and order the parts for that solution just to find that it did not work. Instead, I ordered parts for Solutions A, B, and C simultaneously. Doing this had an accidental, added benefit.
Since the Solution B Knape & Vogt Steel Rollers worked on the first window, that meant that I had pulled a pair of the original Window Master sliding plastic roller assemblies off of the first window. With these two original Window Master sliding plastic roller assemblies I could take my time modifying them for Solution C. I could implement Solution C and then take out the next sliding aluminum window, swap the assemblies, and repeat this process window by window. I did not have repeatedly to take windows out and put them back and/or leave them open while I modified the original plastic assemblies. The pair of Knape & Vogt Steel Rollers effectively meant that I have spares to work on for Solution C.
How to do Solution C: Modify the original small plastic roller assembly to accommodate metal rollers.
Solution C is the least expensive solution from a parts standpoint, but it requires more tools, time, and Mr. Fixit skills that the other solutions. I used Solution C on most of my windows, because it was relatively cheap to order all the parts that I would need, if I intended to replace the pair of nylon rollers on all ten of the Window Master sliding aluminum windows in my house.
The parts needed can be found on Amazon and elsewhere on the Internet. The reason I ordered 20 of each of what I needed was simply that a smaller quantity ordered did not cost that much less. I figured that if this worked, I would not need to reorder — and it did work. If you do not need as many parts as I did, so you probably can save a few bucks on a smaller order quantity.
Here are the parts needed. There were a variety of manufacturers. I chose to order from the same manufacturer, uxcell, on Amazon to ensure that the dimensions and tolerances were consistent. I wanted to ensure that the 4 mm pin would fit into the 4 mm metal roller hole.
You need to order exactly these dimensions to make this work in the original Window Master sliding plastic roller assemblies:
uxcell U624ZZ Deep Groove Guide Pulley Rail Ball Bearings 4x13x7mm 20pcs (Double Metal Shielded Carbon Steel Bearings)
The center hole is 4 mm and the diameter is 13 mm, which is very close to 1/2 inch. The 7 mm dimension is the width of the roller, which fits nicely in the original plastic roller assembly and the groove in the roller keeps the roller on the horizontal track in the window frame.
The 4×20 mm Clevis pin axles with cotter pins:
uxcell 20Pcs M4x20mm Clevis Pins, 304 Stainless Steel Single Hole Clevis Pin (Flat Head Hairpin Location Pin with Cotter Pins)
The diameter of the pin is 4 mm which is approximately twice the diameter of the existing pins in the original 1/2-inch white plastic nylon roller. One end of this clevis pin has a head like a nail and the other end has a hole for the small cotter pin. 20 mm is the length of the Clevis pin which is exactly the length needed to fit. This particular clevis pins kit included the cotter pins.
The total cost for 20 rollers, 20 clevis pins, and 20 cotter pins was $21.
How to modify the original Window Master sliding plastic roller assemblies to fit the 4x13x7 mm metal rollers and 4×20 mm clevis pins.
- A) Set up on the kitchen table or on your workbench and layout plastic or a newspaper (remember them?) to catch debris. This is relatively mindless work, so I watched TV while doing the modifications.
- B) Remove the original white nylon roller and pin from the original plastic roller assembly housing
- C) Hold the original plastic roller assembly with a pliers, and use a fine-grained saw to cut off the two outside plastic nubs on opposite sides of the lengthwise dimension of the plastic roller assembly. I used a hand miter saw to do the cutting.
- Note that these plastic nubs were at the ends of the original metal pin axles. Keep this in mind, because this is the location that needs to be bored out so that the larger 4 mm clevis pin can fit through the original plastic assembly housing.
- Note that the original plastic roller assembly is quite rugged, but do not put excessive force on it to avoid cracking. (None of these did crack, while I was doing these modifications.)
- D) The long sides of the original plastic roller assembly have two slots that go half way down. It helps to lengthen these slots by about 2 mm by repeatedly snipping the plastic with a mid-sized wire current pliers. You angle the wire cutter blades down the channel and only snip a bit of the plastic at the end of the channel. This just makes the next step a bit easier.
- E) With increasing drill bit sizes use an electric drill to reem out a larger hole for the 4 mm clevis pin to pass through the sides of the original plastic housing. Be careful and do not overdo the reaming. You just need the 4 mm clevis pin to pass through the sides of the original plastic housing. During operation, the clevis pin does not need to rotate. In fact, it will stay stationary pressed against the bottom of the aluminum window. The 4x13x7 mm rollers have their own internal bearings which do all the rotating.
- I started reaming with a 1/8-inch drill bit while pulling the drill back and forth. I finished with a 5/32 drill bit, which allowed the 4 mm clevis pin to pass through the sides of the original plastic housing.
- F) Take a small narrow file and clean up any plastic burrs on the original plastic housing. This will prevent then later from interfering with the rolling of the window. Also, you may want to take a small to medium rat tail file and carve off some of the plastic on the short sides of the original housing that would run along the roller track in the window frame. You can see where this might have happened, because once the white nylon roller gets worn done the track starts to scrape into the original roller housing.
- G) Do the assembly. Slide the 4 mm clevis pin through one side of the original plastic housing. Then, position the 4x13x7 mm roller in the middle of the plastic housing and push the 4 mm clevis pin through the center of the roller. Next, continue pushing the clevis pin through the other side of the original plastic housing. Finally, attach the cotter pin through the hole at the end of the clevis pin and bend the cotter pin around the clevis pin. You will need a needle nose pliers and some other tools to stabilize the pin when bending the cotter pin.
- H) Now you are ready to put the original plastic housing with new metal roller back into the bottom of your window, and then to install the window back in its frame. Note that the original modified plastic housing with new clevis pin and roller will only fit into the window base one way, which will be obvious to you.
