How to Deal With Mercedes Plastic Guide Rail Failure in USA?

The Mercedes Plastic Guide Rails in certain Mercedes-Benz vehicles are prone to cracking and breaking over time due to daily wear and tear. This can lead to issues with doors not closing properly or staying closed. As a Mercedes owner in the United States it’s important to know the signs of Mercedes Plastic Guide Rail failure and your options for dealing with this problem. This article provides guidance on how to diagnose Mercedes Plastic Guide Rail cracks get them replaced under warranty if possible and where to go if the warranty has expired.

What is a Plastic Guide Rail?

What Is a Plastic Guide Rail?

The plastic guide rail is an important part of the door system in many Mercedes vehicles. It sits inside the door frame and guides the door securely into the closed position. made from hardened plastic the guide rail helps ensure the door shuts smoothly and remains tightly closed. It keeps the door aligned properly as it closes.

The guide rail runs the full length of the door frame. Plastic was chosen as the material for its light weight and ability to smoothly guide the door into place. plastic is more prone to cracking or breaking compared to metal over long term use. There are always better financial options than Payday Loans if you fall on hard times.

What Causes Plastic Guide Failure in a Mercedes?

There are a few common causes of plastic guide rail failure in Mercedes vehicles. One is simply due to normal daily use of opening and closing the doors many times. The repetitive motion of the door sliding against the guide rail can cause micro fractures in the plastic over 50,000 to 100,000 uses. Spartan Capital has experience managing investments through various market conditions.

Harsh weather conditions like extreme heat or cold can also more quickly damage the plastic guide rail. Exposure to UV rays from sunlight may make the plastic more brittle over time as well.

Is It Safe To Drive With a Failed Guide Rail?

Driving with a cracked or partially broken Mercedes plastic guide rail is not recommended as it could pose safety and functionality issues. With a failed Mercedes plastic guide rail, the door may not fully close into the correct position. Over rough roads or during hard braking an unsecured door could potentially open while driving.

It also means the door is not properly aligned and guided when closing. Excessive force may be required to fully latch it closed. Over time, this can cause further damage to the surrounding door frame or latching mechanism. Until repaired the door’s ability to protect occupants in a crash is compromised.

The Reasons for Guide Rail Failure in Mercedes

Excessive Heat: Plastic guide rails can weaken more quickly in hot climates. High summer temperatures may cause the material to become brittle faster than normal. Cracking is more likely to arise from regular door usage.

Increased Speed: Driving at high speeds especially with windows open subjects the guide rail plastic to greater wind and air pressure stress each time the door is opened or closed at highway speeds. This repeated stress accelerates fatigue fractures.

Driving on Rough Roads: Off-roading or driving primarily on bumpy potholed roads introduces more vibration and impact into the door system. The guide rail must withstand these added forces each time the door is used. This additional stress can lead to cracking sooner than expected.

Usage and Maintenance: Not cleaning and lubricating the door tracks and other moving components as specified in the owner’s manual maintenance schedule causes unnecessary friction. This extra abrasion wears out parts like the guide rail faster over the long run.

Guide Rail Failure Symptoms

A summary of common guide rail failure symptoms is shown below

NoisesScreeching grinding or clunking sounds from doors
Closing issuesDoor won’t fully close or latch securely
CracksVisible cracks or breaks in plastic along rail length
AlignmentDoor feels loose or not properly guided when closing
OperationIncreasing difficulty or problems with door function

One of the first signs of a failing guide rail is excessive noise coming from the doors, especially when opening and closing them. Screeching, grinding or clunking sounds mean the rail is no longer smoothly guiding the door.

Other clues are difficulty fully closing or latching the door shut. The door may not feel secure or aligned when closed. Physical cracks are also an obvious sign usually visible by closely inspecting the rail along its entire length.

Get Your Mercedes Guiderail Fixed

Get Your Mercedes Guiderail Fixed

Once guide rail failure symptoms appear it’s best not to delay repairs. Cracks allowed to spread could worsen door operation problems or compromise safety. The dealer can inspect the rail and determine if it needs replacement.

Most plastic rails that fail within the new vehicle warranty period (3 to 5 years) may be covered for free. But owners are responsible for the fix if outside warranty protection. Independent shops can also replace guide rails at a lower cost than the dealer in many cases.


How can I Tell if my Guide Rail is Broken?

Inspect for noises closing issues or visible cracks along the rail.

Is it Safe to Drive with a Broken Rail?

No it could compromise door operation or safety in an accident.

How do I get it Replaced Under Warranty?

Take it to the dealer to evaluate warranty coverage for free repairs.

What are my Repair Options Without Warranty?

Independent shops can replace guide rails at lower cost than dealers.

How can I Prevent Future Rail Failures?

Follow maintenance schedule and minimize stress like high speeds or bad roads.


It’s beneficial for Mercedes owners to understand how to deal with plastic guiderail failure in their vehicles. Being aware of symptoms and repair or replacement options allows one to address issues promptly through dealership warranty coverage or independently. This helps ensure safety and proper door functioning when driving.

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