Why choose the RAC for an automatic transmission fluid top-up?

At the RAC, we've got over 125 years' experience helping UK drivers. We have the skills and knowledge to keep your vehicle running. We'll give you results you can rely on at a price you can afford.

Automatic Transmission Fluid Change for Mercedes vehicles requires specialist tools and workshop facilities, so this work is completed through the RAC Approved Garage Network. Our approved garages service models such as A-Class, C-Class, GLC, E-Class, and EQA, following manufacturer procedures, certified equipment standards and rigorous quality checks. You receive transparent pricing, progress updates and RAC‑backed guarantees.

Close up of an RAC Mobile Mechanic underneath a car
A mechanic standing inside a garage

Book an automatic transmission fluid replacement

To help make sure you’re getting smooth gear shifts and a long transmission life you need to maintain your automatic transmission fluid. So when you need to, make sure you have that old fluid drained and refilled at an RAC Approved Garage.

Any work done will meet the high standards set by the RAC.
We’re friendly, straightforward and jargon-free
A mechanic inspecting the underside of a vehicle.

Book a diagnostic

A mechanic will check your car for faults and talk you through any repairs you might need. There are various ways to check for faults, which could include a physical examination or plugging in to check your car’s onboard engine management system.

We’ll look for any mechanical or electrical problems. If we need to, we’ll also check your car’s onboard engine management system. Depending on your car and issue, this will usually include: – Engine – Power steering – Brakes – Transmission – Exhaust system – Fuel injection system – Cooling system and air flow – Sensors

And it’s not just automatic transmission fluid replacements that we can do for your Mercedes

RAC Approved Garages offer MOTs and services. Our professional mechanics have the expertise and experience to make sure your vehicle is operating safely and efficiently – results you can rely on at a price you can afford.

A close up of an RAC mobile mechanic looking under the hood of a car

Try one of our RAC Approved Garages

ZS Motors London Ltd

5.0/5

At ZS Motors London Ltd, we pride ourselves on delivering trusted, high-quality automotive services across Rainham (Essex) and east London. With years of experience in the motor trade, we specialise in MOT, engine rebuilds, servicing, diagnostics, and repairs for a wide range of makes and models. Our mission is simple to provide honest advice, reliable workmanship, and excellent customer service. Whether you’re buying your next car, maintaining your current one, or in need of emergency repairs, our expert team ensures your vehicle is always in safe hands. Based in Rainham (Essex) East London, we have built our reputation on transparency, integrity, and a commitment to keeping our customers on the road with confidence.
Unit 3 And 4 Blackwater Close, Fairview Industrial Park, Rainham, RM138UA

Sahibs Auto Electric

4.0/5

We are London's go to centre for MOT, Servicing, Alternators, Starter Motors and Car Diagnostics. We pride ourselves in Car Electrics and are well renowned for are specialists in Car Alternators and Car Starter Motors. Established in 1980, we have nearly 40 years of trusted experience the industry.
3 Norbreck Parade, London, NW107HR

Jh Automotive

4.3/5

Jh Automotive is based in Chertsey. We do all range of vehicle makes but specialise in BMW & VAG. We have years of experience within our team and ensure to deliver the experience of hassle free maintenance and repairs, this could be helped with the option to wait while we carry out the work or us coming to collect the vehicle and drop it back! We look forward to hearing from you.
Unit 1 Green Acres Farm, Chertsey, KT160AD

GT Automotive Group ~ Sheffield

4.5/5

GT Automotive offers a comprehensive range of Aftersales services and vehicle repairs from our fully equipped onsite workshop. Our highly skilled and qualified technicians bring years of experience across multiple vehicle brands. Every vehicle that comes to us receives a FREE health check, including a full digital report for your peace of mind and safety. To make maintenance more manageable, we also provide 0% finance options over 3 or 6 months. Customers can relax in our comfortable waiting area with refreshments, or take advantage of our collection and delivery service available for local customers. As a proud family-run business, we’re committed to serving our local community with honesty, care, and exceptional service.
1 Orgreave Way, Sheffield, S139LS

Redburn Mot and Service Centre , Bosch Car Service

4.8/5

WE ARE WHO CAN FIX MY CAR 2018 AWARDS FINALISTS. Looking for great value car servicing? Need a reliable MOT test centre? We are specialists offering a full range of car servicing / repairs and MOT's at great prices. In addition we offer air con re-gas, tyre supply and fitting, tracking and laser alignment and full diagnostics. We pride ourselves on our excellent service and our 5-strong team of trained mechanics will be happy to answer all of your questions regardless of your vehicle make or model. Call us today for a great deal on your next car MOT or car service. Our state of the art facility has everything we need to offer comprehensive care for your vehicle,
Unit 9A/B Cowley Road, Blyth Riverside Industrial Estate, Blyth, NE24 5TF

Frequently asked questions about automatic transmission fluid change

Automatic transmission fluid should be changed every 30,000 to 60,000 miles. However, always check your vehicle’s manual for the manufacturer’s recommendation. Your driving habits and the conditions you drive in will affect how quickly your fluid degrades. Regular checks and following the manufacturer’s guidelines will help to make sure your transmission stays in good condition.

Some people believe that changing old transmission fluid can cause issues, especially in high-mileage vehicles. This myth stems from the fact that when automatic transmission fluid is changed, the new fluid can sometimes dislodge debris, causing problems. However, this is usually due to debris build-up.

If you don’t change the automatic transmission fluid, it can become contaminated and lose its effectiveness, leading to transmission wear and potential failure. Over time, dirty automatic transmission fluid can cause increased friction, overheating, and significant transmission damage. Regular changes will help you avoid costly repairs and keep the transmission running smoothly.

Fresh automatic transmission fluid is bright red and clear. If your fluid looks clean and smells fresh, it’s been changed recently. You can also check the service records for confirmation. If in doubt, ask your mechanic to check.

Signs that you might need a transmission flush include:

  • Slipping gears: The transmission struggles to stay in gear.
  • Delayed gear engagement: There’s a noticeable delay when shifting gears.
  • Overheating: The transmission becomes excessively hot.
  • Unusual noises: Grinding or whining sounds from the transmission.
  • Dirty fluid: The automatic transmission fluid is dark or discoloured.

A flush can help remove contaminants and restore the fluid’s effectiveness.

It’s often best to have a professional do it. The process can be messy and requires proper disposal of old fluid. Professional services also include checks and diagnostics to ensure everything is working.

Transmission fluid is used in automatic transmissions, while gearbox oil is used in manual transmissions. They’re made to do different jobs, so they’re not interchangeable. Automatic transmission fluid is designed for the hydraulic and cooling needs of automatic transmissions, while gearbox oil provides the necessary lubrication for manual transmissions.

An automatic transmission flush is a service where all the old automatic transmission fluid is removed, and new fluid is added. It helps remove contaminants and old fluid that might be stuck in the transmission. It’s more thorough than a simple fluid change and can help restore the transmission’s performance.

Yes, changing the automatic transmission fluid is necessary to keep your vehicle’s transmission running well. Over time, the fluid degrades and becomes less effective, leading to potential transmission problems. Regular changes help the transmission run smoothly and can prevent costly repairs down the line.

To extend the life of your automatic transmission fluid:

  • Regular maintenance: Follow the manufacturer’s guidelines for fluid changes.
  • Avoid excessive heat: Don’t overload your vehicle or tow heavy loads when you don’t have to.
  • Check for leaks: Regularly inspect your vehicle for fluid leaks.
  • Smooth driving: Avoid aggressive driving habits that can overheat the transmission.

Proper care and regular upkeep can significantly extend the life of your automatic transmission fluid and transmission.

An automatic transmission fluid change will typically take about 1 to 2 hours, depending on the vehicle and the service provider. This includes draining the old fluid, replacing the filter (if necessary), and refilling with new fluid. If more services or diagnostics are needed, it could take longer.

If your transmission fluid is low:

  • Check for leaks: Look for any visible leaks under the car.
  • Top up the fluid: Use the right type of fluid for your vehicle.
  • Monitor the fluid level: Regularly check the fluid level to make sure it stays within the recommended range.
  • Consult a mechanic: If the fluid level continues to drop speak to a mechanic so that they can inspect and fix any issues.