Wiper linkage for your car

Keeping the windscreen clean: windscreen wiper linkage

The windscreen does more than shielding from the wind. It is a basic condition for the free forward view. It always must be clean to enable the driver to see everything going on in front of him. To this end, every car is equipped with windscreen wipers. Correctly moving them is the task of the wiper linkage.

Location and construction of the wiper linkage

The wiper linkage is situated under a cover at the top end of the bonnet right in front of the windscreen frame and fixed to the bodywork. An electric motor drives the linkage. Its characteristic kinetics are the back-and-forth movement, the optimal motion over the windscreen for the connected wipers. Station wagons and hatchback cars have wipers on the tailgate. Here too a wiper linkage is installed, though of a much simpler construction.

Wiper linkage defects

The wiper linkage is not a wear part and usually lasts a car's life time. Particularly detrimental to the wiper linkage is faulty usage. Attempting to use a wiper which is frozen to the windscreen, to name an example, can lead to defects of linkage and motor. The linkage stretches, the transmission snaps or the motor overheats. Excessive strain in rainy areas can also cause stretching of the linkage. The bushings of the linkage get too much play or the kinematics bend. Furthermore, rust can affect the linkage. Repair is not really an option. The linkage is an intricate construction and would no longer function properly after partial repair. The best way is replacement of the entire unit. Another argument in favour is the fact that wiper linkage is generally not very expensive If wiper linkage fails, something got stuck in the mechanics and subsequently tore itself free. This has an obvious effect. The wiper remains standing still on the windscreen. Sometimes, a wiper linkage defect is announced by grinding noises.

Replacement of the wiper linkage

The wiper linkage is replaced with open bonnet. It is usually situated under a plastic cover right in front of the windscreen. The proper order for replacement is:

• Open the bonnet.
• Remove the sealing lip and the plastic covers.
• Disassemble the wiper arms. (The bolts sit under the plastic cover on the rotation point of the wiper arms).
• Remove all covers which are in the way of disassembly of the wiper linkage.
• Unscrew the wiper linkage bolts.
• Adjust the motor from the old to the new wiper linkage.
• Install the new linkage – done.

At installation all moving points should be thoroughly lubricated. Terminal grease is very suitable as it lasts a long time and adheres adequately. WD-40 is less suitable, as its adherence is not that good. Alternatively, the wiper blade can be completely oiled once a year. This adequately prevents occurrence of new damage. After installation of the linkage the motor must be adjusted to the linkage. To do so, a detachable bolt can be found between linkage and motor.

Assistance in case of jamming wiper arms

The wiper arm can jam due to corrosion of the interlocking. Even pulling strongly will not help. The connection must be loosened with rust solvent and penetrating oil, e.g. WD-40. If this does not work, a bearing removal tool is the best tool. Refrain from working with heat on this point. The windscreen sealing rubber sits in the immediate proximity. If the wiper arm bolt is heated by a flame, the rubber can melt. A permanently leaking windscreen is the result.

Costs for a new wiper linkage

A purchase of a linkage depends on whether or not the motor must be replaced. Without motor, linkage is very cheap, starting at ca. EUR 15 (± £13). For average cars, 30 EUR (± £26) is a reliable reference value. Including a motor the wiper linkage becomes quite expensive. Be prepared for over 100 EUR (±£90) for the spare part. Therefore always try using the old motor first. It is quite a robust component. As long as it is not charred with a burnt smell, it is usually still in good working order. Thoroughly cleaning it should suffice. This especially applies to its contact points and the plug connection to the onboard wiring.