Windscreen wiper arms wear out and need replacing, usually every three to five years

A windscreen wiper arm is the metal or plastic rod that holds the rubber blade and moves it across your windscreen. Over time, the arm's joints weaken, the metal corrodes, or the connection to the motor loosens. When this happens, the blade no longer sits flat against the glass, streaks appear, or the arm stops moving altogether. Replacing the arm is a straightforward job that takes 10 to 20 minutes and costs between £15 and £50 per arm, depending on your vehicle make and model.

You can do this work yourself with basic tools, or a garage can do it for you. The process is the same either way: disconnect the old arm from the motor spindle, remove the blade, slide the new arm onto the spindle, and reconnect it. No welding, no special equipment, and no need to remove the windscreen.

Key Takeaways

  • Wiper arms typically fail because the metal joint weakens, the blade holder cracks, or the connection to the motor spindle loosens over time.
  • You can replace a wiper arm yourself using only a socket set, screwdriver, and the new arm — the job takes about 15 minutes per side.
  • The arm connects to the motor spindle with either a nut and bolt, a clip, or a push-fit connector, depending on your car's age and make.
  • Buying the correct arm for your vehicle requires the registration number or the exact make, model, and year — wiper arms are not universal.
  • If the arm is stuck or corroded, penetrating oil and patience work better than force, which can damage the spindle or windscreen.

Signs that a wiper arm needs replacement

The most obvious sign is that the blade no longer makes contact with the windscreen across its full width. You may see streaks, dry patches, or the blade chattering as it moves. Sometimes the arm itself is visibly bent, cracked, or hanging loose. In winter, ice can freeze the arm to the windscreen; if you force it, the arm may crack or the connection to the motor may snap.

A second sign is noise. If the arm squeaks, clicks, or rattles during use, the joint is usually worn. The arm may also move slowly, hesitate, or stop partway across the glass if the motor is struggling against a stiff or misaligned arm.

Less common but important: if the arm has been in a collision or you have hit something with the wiper extended, the arm may be bent even if it still moves. A bent arm will eventually damage the blade and the motor, so replacement is worth doing before that happens.

How to identify which arm you need to buy

Wiper arms are not universal. The spindle diameter, the blade attachment method, and the arm length all vary by manufacturer. Buying the wrong arm means it will not fit, or it will fit but the blade will not sit flat.

The safest way to order the correct arm is to give your vehicle's registration number to the parts supplier — they will look it up in their system and send you the right one. If you do not have the registration, provide the make, model, and year of manufacture. Some suppliers also ask whether you want the driver's side or passenger's side arm; these are sometimes different lengths or have different connectors.

If you are buying in person at a motor factors or online, check the product description for your exact vehicle. Many listings show a photo of the arm and list compatible models. Do not assume that because your car is a Ford Focus, any Focus wiper arm will work — the arm for a 2010 Focus may not fit a 2018 Focus.

Tools and materials you will need

To replace a wiper arm yourself, gather the following:

  • A socket set or adjustable spanner (usually 10mm or 13mm, depending on your car)
  • A screwdriver (flathead or Phillips, depending on the fastener)
  • The replacement wiper arm, ordered for your specific vehicle
  • Penetrating oil such as WD-40 (if the old arm is stuck or corroded)
  • A clean cloth or rag
  • Masking tape or a marker (optional, to mark the position of the old arm before removal)

You do not need to remove the windscreen, lift the car, or disconnect the battery. Most wiper arms are held on with a single bolt or clip that you can access from the top of the motor housing.

Step-by-step replacement process

Before you start, park on level ground and turn off the engine. Lift the wiper arm away from the windscreen so it stands upright — this gives you room to work and reduces strain on the motor.

Locate the connection point where the arm meets the motor spindle. This is usually a small bolt, a clip, or a push-fit connector at the base of the arm. If you are unsure, consult your vehicle's manual or search online for your make and model.

If the connection is a bolt, use the socket set or spanner to loosen and remove it. If it is a clip, press or pry the clip outward to release the arm. If it is a push-fit connector, you may need to press a small tab or lever while pulling the arm away from the spindle. Mark the position of the old arm with masking tape or a marker before you remove it — this helps you position the new arm correctly later.

Once the arm is free, slide it off the spindle. If it is stuck, spray penetrating oil around the base and wait 10 to 15 minutes before trying again. Do not force it; forcing can bend the spindle or crack the windscreen frame.

Slide the new arm onto the spindle, aligning it with the mark you made on the old arm. The arm should sit at roughly the same angle as before. Reconnect the bolt, clip, or push-fit connector. Tighten the bolt firmly but do not over-tighten, which can strip the threads or crack the arm.

Lower the wiper arm back onto the windscreen and test it by running the wipers through a full cycle. The blade should make even contact across the glass and return to the parked position at the base of the windscreen. If the blade is not sitting flat or the arm is not returning to the correct position, stop and recheck the alignment.

Common problems and how to solve them

The old arm is stuck or corroded. Spray penetrating oil around the base where the arm meets the spindle. Wait 15 to 30 minutes, then try again. If it is still stuck, explore more oil and wait overnight. Patience is more effective than force, which can damage the spindle or windscreen frame.

The new arm does not fit the spindle. This usually means you have ordered the wrong arm for your vehicle. Check the product description against your registration number or vehicle details. If you ordered in person, return to the supplier with your registration and ask for the correct part.

The blade does not sit flat after replacement. The arm may not be aligned correctly on the spindle. Remove it and reposition it so it sits at the same angle as the old arm did. If you did not mark the old position, consult your vehicle's manual or search online for the correct parking position for your make and model.

The connection bolt keeps loosening. Tighten it firmly, but do not over-tighten. If it continues to loosen, the threads may be stripped. In this case, you may need a slightly larger bolt or a thread-repair insert, which a garage can fit.

When to take your car to a garage instead

If the old arm is severely corroded or stuck and will not budge after several applications of penetrating oil, a garage has better tools and experience to remove it without damage. If the spindle itself is bent or damaged, the motor housing may need repair or replacement, which is beyond a straightforward arm swap.

If you are not confident working with tools or do not have the right socket size, a garage can do the job quickly and cheaply — usually under £50 in labour plus the cost of the arm. Many garages will fit a wiper arm while you wait.

Frequently Asked Questions

Can I replace just one wiper arm, or do I need to replace both?

You can replace just one arm if only one is worn or damaged. However, if both arms are old, replacing both at the same time means they wear evenly and you avoid a second replacement soon after. Wiper arms typically last three to five years, so if one has failed, the other is usually not far behind.

Do I need to replace the blade at the same time as the arm?

Not necessarily. The blade and arm are separate parts. If the blade is in good condition, you can keep it and straightforward transfer it to the new arm. If the blade is worn, cracked, or streaking, replace it at the same time — blades are cheap and the job takes an extra two minutes.

What is the difference between a driver's side and passenger's side wiper arm?

On most cars, the arms are mirror images of each other and have different lengths or connector types. Some vehicles use identical arms on both sides. Always check your parts order to make sure you have the correct side, or the arm will not fit or will sit at the wrong angle.

Will replacing the wiper arm affect my car's warranty?

No. Wiper arms are wear-and-tear items, and replacing them is routine maintenance. Your warranty covers manufacturing defects, not normal wear. Replacing a wiper arm yourself does not void your warranty on other parts of the car.

How do I know if the motor spindle is damaged and not just the arm?

If the old arm comes off easily but the new arm does not sit firmly on the spindle, or if the spindle is visibly bent or cracked, the spindle is damaged. In this case, the motor housing may need repair. If the spindle looks intact and the new arm fits snugly, the problem was just the arm.