Mercedes W124 / W201 / R129 Wipers Stopped or Slipping? Replace the Wiper Gear (A1248202307)

If the wiper motor on your Mercedes W124, W201 (190) or R129 SL hums or clicks but the arms stop mid-sweep, move slowly or do not return to the parked position, the gear inside the wiper transmission is a common suspect. In many cases the transmission can be repaired by replacing that gear instead of buying a complete mechanism.

This guide shows what to check before ordering the FIXHEN reinforced wiper gear, OEM A1248202307.

Fitment at a glance

OEM reference: A1248202307. The gear is for Bosch wiper mechanisms only, so check your system type before ordering.

Typical symptoms

• The motor runs, but the wiper arm stops partway across the screen.
• The arm moves jerkily, slips or loses its sweep under load, for example on a dry or iced screen.
• The wiper does not return to its normal park position.
• You hear grinding or clicking from under the cowl panel.

These symptoms do not prove the gear has failed. Worn linkage joints, a seized wiper spindle or an electrical fault in the motor or relay can look similar, so check those as well.

Why the gear wears

These cars are now 25 to 40 years old. The gear in the transmission takes the full load every time the wipers start, change direction or push through snow and dirt. Over time the teeth of the original plastic gear wear down or break, and the motor then spins without moving the arms properly.

A quick check

1. Switch the ignition off and remove the cowl cover under the windscreen.
2. Run the wipers briefly and watch where the movement stops: at the motor, at the transmission or at the linkage.
3. With the ignition off, try moving the arm by hand. Excessive free play or a crunching feel points to the gear.
4. Open the transmission and inspect the teeth. Missing, rounded or cracked teeth confirm the problem.

Replacement overview

1. Disconnect the battery and mark the parked position of the wiper arm.
2. Remove the wiper arm and the cowl panel.
3. Unbolt the wiper mechanism and lift it out with care, without forcing the linkage.
4. Open the transmission housing and remove the worn gear.
5. Clean out the old grease and debris, then fit the new gear with fresh grease.
6. Reassemble, refit the arm in the marked park position, and test on a wet screen.

Model years and equipment differ, so follow the workshop procedure for your car. If you are unsure, have a workshop do the job.

Why a reinforced gear?

The FIXHEN A1248202307 gear is made from PA6-CF, a polyamide reinforced with carbon fibre. It is designed for higher strength and better wear resistance than standard plastics. It fits as a direct replacement, with no modifications.

FAQ

Does it fit every W124?

It fits cars with the Bosch wiper mechanism. Check your mechanism and the OEM reference A1248202307 before ordering.

Do I need to replace the whole wiper transmission?

Not if only the gear is worn. If the housing, spindle or linkage is also damaged, those parts need attention too.

Is this a DIY job?

Many owners do it themselves with basic hand tools. The main risks are getting the park position wrong and putting the linkage back in the wrong order.

Ready to fix it? Order the reinforced wiper gear A1248202307.