How to Service Windscreen-Wipers

How To Service The Windscreen-Wiper?

There are many methods that make it easier for you to know how to service the windscreen-wiper mechanism. If your windscreen wiper blades are either streaky, squeaky, or visibly worn out, it’s probably a good time to service or replace the windscreen wipers.

If your windshield wipers aren’t working properly, you’ll be at risk. It’s important to check and service your windshield wipers, and if they’re faulty, you have to replace them. Faulty wipers or ones that aren’t working can cause many accidents and to avoid them and other inconveniences. We’ll let you know everything necessary related to windshield wipers.

Windscreen wiper linkage and its types

The wiper transmission mechanism and the wiper motor present at the front are installed under the windshield in the cowl panel cover. The transmission mechanism is called linkage, and it has two types. Whenever there is a problem with the windscreen wiper mechanism, it’s almost always related to the linkage.

Pushrod Linkage

The pushrod linkage is relatively straightforward. A gear turns a crank that controls the pushrod. There is a link rod that carries the wiper arms. This link rod is pivoted to the pushrod. The pushrod pushes and pulls a rigid link rod that is horizontally placed. There is a wiper arm spindle at all ends that the pushrod uses to push and pull.

The Rack and Wheelbox Linage

This type of linage consists of a flexible long rack and a screw head rod encased in a tube. The connecting rod of the motor and gear pull it back and forth.

Two wheelboxes or sometimes more are mounted on each of the tubes. Each of them has a gear wheel. This gear wheel is meshed with a stretch of exposed thread placed on the rack. The wheels convert the movement of the rack to a swinging action of the wiper arms, which are mounted on the wheel spindles.

How a Windshield-Wiper Mechanism works

When you turn on the wiper, a signal is passed from the wiper switch to the control module. The control module runs the wiper relay. A voltage of 12 volts is sent to the wiper motor from the relay. The motor rotates a small arm. This arm goes through the links to move the wiper arms. This is how a basic windshield wiper mechanism functions.

Servicing A Windshield Wiper Mechanism

A wheelbox wiper mechanism can sometimes be prone to sticking, or the wheels can wear out. This can allow excessive amounts of play that makes the wiper arms move way far than normal. To test a wheelbox wiper mechanism is sticking, lift the wiper arms from the screen and remove the motor gearbox covering.

Unscrew the nut that locks the tube to the gearbox. Then, remove the washer and circlip. This will loosen the rack from the rod. Lift the rack. At the top of the rack, hook a spring scale. Then, hold the tube and pull the rack. Keep pulling it until the wiper arms start moving. Measure the weight of the pull.

The force needed will be around 2.7 kg at most. If a lot more force is needed, the rack and the wheelbox may need to be lubricated. The tube could also be a little too curved, far from the motor. None of the bends is supposed to have a radius smaller than 9 inches. You’ll have to shape the bend with your hand. In order to lubricate the rack, remove it from the tube and grease it up that has a high melting point.

Remember to reposition it when you’re rethreading so that the unworn threads are against the gear wheels. When the rack is taken out, lubricate the wheelboxes. Begin with the wiper arms, then go to the nuts of each of the spindles. See how the spacers and washers under the nuts are arranged. Pull the tube out from all sides and take out the screws that hold in the wheelboxes. Use high melting point dielectric grease to pack the wheelboxes and then proceed to resemble when it’s all finished.

Wiper Troubleshooting Tips

Wipers are important parts of your car. Without a windshield wiper, you’d be unable to clean your windshield if its pouring hail or raining and heavy rain or hail can badly damage a car. You can protect your car from hail by other methods but as for rain, the wipers are your only savior. Just like how it’s important to clean the interior of your car, it’s equally necessary for your windshield wipers to be clean and free of any issues.

A windshield wiper can either have an electrical problem or a mechanical one. The mechanical problem occurs with the transmission, and an electrical problem occurs with the wiper motor circuit. Keep a multimeter for testing close by in case for an electrical problem.

The wiper arm shaft seizing up inside the linkage

The wiper linkage (wiper transmission) has two shafts that hold the wiper arms. The common problem is that one of the wiper arms would often seize up completely or move slower. You’ll have to lubricate and clean the shafts without replacing any part to fix this issue. This is a cheaper alternative, but if you want to solve the issue completely, you’ll need a replacement for the linkage.

Sometimes, the seized-up wiper arm can overheat the wiper motor, which stops working. You’ll have to replace the wiper motor if this happens.

Wipers working but stopping at the wrong position

Several reasons can cause this issue, but at times, the small motor arm connected to the wiper motor can get loose and moves to the motor shaft. It makes it stop at the wrong place. Checking the connection and other electrical connections will avoid such issues.


When the weather is chaotic, your car goes through a lot. If it’s a storm or if its hail then you’ll get your windscreen dirty, sometimes a big enough hail can even cause a dent in your car too. To be safe in such conditions. You should know how to service the windshield-wiper mechanism and test it for any faults.