126 Window Regulator Plastic Slide Replacement Kit

W126 chassis Gasoline and Diesel models 1981 to 1991

Fits all 126 chassis sedans 1981 to 1991. Depending on the type of regulator you have it may or may not apply to all four of your doors. Recommend you remove the door panel first to inspect (see below). If any of your regulators use a white plastic slide for the bottom rail on the window then this kit will work. Replacing the plastic slide on a broken window regulator with this improved part is a great way to save money and prevent future re-occurrence of this common problem. The original factory part is a two part hollow piece and very prone to breaking apart. The replacement part we offer is a solid piece of plastic and from my experience just does not fail. 2 slides are included in this kit. Only one is needed for each door. Since the rear doors are the ones that fail most often we include 2 for both your rear doors ( for all W126 sedans with factory power windows from 1980 to 1991). You must remove your front door panel to determine if you have the type of regulator that uses these slides. 

126 Window Regulator Plastic Slide Replacement Kit
Free Add-Ons Included:

126 Chassis Plastic Window Slide Upgrade Replacement Instructions By Kent Bergsma - Download

Product Details

This kit includes the following:

  • 2 heavy duty solid plastic slides with new rivet pins
  • Special backing tool to help you install the rivets
  • Small container of synthetic grease (very best grease for plastic slides)
  • Complete pictorial instructions to install new slides in PDF format* (door panel removal instructions not included - see below)

IMPORTANT NOTE: The rivet size in our kit fits the arm holes in most W126 sedans, but a few of the early models had smaller rivets. In the picture below you can see the difference between the rivet diameter and the hole in the rear window regulator arm. If you find that is the case with your regulator, you will need to drill the hole out with a 9/32 inch drill bit ( or you can use a 1/4 inch drill bit and then a small round file to enlarge the hole until the rivet just slips in. Don't make the hole too large or you may not be able to pien the rivet tight in the hole. 


How to view the PDF digital instructions:

Once you complete the purchase of this product you will be able to download the digital instructions immediately when you are logged in and on your personal account page (click on My Account). Any PDFs will show up under My PDF Manuals. You will be allowed three downloads, so please save the file on your machine for backup.


First sign of trouble is your window will not move full travel and may even jam. You most likely will hear the window motor running but the window will not be moving! Immediately remove your door panel and inspect to prevent further damage. (If you are not familiar with removing the door panel or the window regulator I recommend you purchase my manual on 126 Door Maintenance and Repair ) Once the panel is removed look at the bottom track of the window to see if the aft arm of the regulator has come off the track. If so, a broken plastic slide will most likely be the problem. 

WARNING: It is possible to damage the plastic slide during assembly if you are not careful when riveting the pin to the regulator arm. If you bang on pin with the slide laying on a flat surface you will stress the plastic and it may break apart when installed in the window channel.

New slide installed and regulator ready to go back into the car:

DOUBLE WARNING WARNING:  If your new slide brakes and it was installed properly it is not a problem with the slide. If the window is binding due to lack of lubrication or a bent regulator it can put excessive stress on the plastic slide. This type of stress can break the slides as you will note in this picture. With the arm disconnected you should be able to EASILY PUSH THE WINDOW UP AND DOWN BY HAND. If not the rails and channels need to be lubricated thoroughly until the window moves up and down easily… In this case, it appears the arm is not aligned properly with the bottom of the window. That means the window regulator is bent and putting stress on the slide. The regulator should be removed straightened and properly lubricated. Once that is done the slides won’t be under stress anymore.