Transmission Fluid Change: When, Why, and How Often?

Transmission fluid is a specialized lubricant designed to keep your car’s transmission system, which is responsible for transferring power from the engine to the wheels, operating smoothly.

Regularly taking your car for maintenance at an auto repair shop can help keep your car’s transmission system in good condition. During regular maintenance, auto repair shops check and change transmission fluid as needed. Here’s a short guide to when, why, and how often to change transmission fluid:

When to Change Transmission Fluid

Knowing when your car’s transmission fluid needs to be changed involves paying attention to several indicators, both through regular checks and observing the vehicle’s performance.

Fresh transmission fluid is typically bright red or pink. Over time, it may turn dark brown or even black, indicating it is contaminated and needs changing. Healthy transmission fluid has a somewhat sweet smell. If the transmission is overheating, it may be due to degraded transmission fluid that is no longer able to cool the system effectively. If the transmission fluid smells burnt or has an unusual odour, this is a sign of overheating or significant degradation. If your vehicle has a transmission fluid dipstick, you can use this to check the fluid level and condition.

You may also notice some changes to your vehicle’s performance. If the transmission slips out of gear or has difficulty staying in gear, it may indicate that the fluid is no longer providing adequate lubrication. Hesitation, rough, or jerky shifting can also be a symptom of old or insufficient transmission fluid. Finally, grinding, whining, or clunking noises when the transmission shifts can indicate issues that may be related to the transmission fluid’s condition.

Nowadays many vehicles have sensors that monitor the transmission. If the check engine light on your car comes on, it could be related to the transmission fluid’s condition.

Why Change Transmission Fluid

Fresh transmission fluid ensures that the transmission operates smoothly, helps maintain proper hydraulic pressure, and allows for smooth gear shifts.

Like any lubricant, transmission fluid breaks down over time due to heat and friction. Transmission fluid can also accumulate debris such as metal shavings, dirt, and other particles. These contaminants can cause increased friction and wear on the transmission. Additionally, exposure to high temperatures can cause the transmission fluid to oxidize, resulting in a thickened, varnish-like substance that can impede the fluid’s flow and its ability to lubricate properly.

As it degrades, transmission fluid loses its effectiveness in lubricating and protecting the transmission components. Regularly changing the transmission fluid can prevent excessive wear and tear, overheating, and potential transmission failure, which are costly to repair.

How Often to Change Transmission Fluid

The frequency of transmission fluid changes depends on several factors, including the type of transmission, driving conditions, and the specific vehicle manufacturer’s recommendations. Your car’s manual will typically provide guidance on intervals for when the transmission fluid should be checked and changed.

Generally, it is recommended to change transmission fluid every 50,000 to 100,000 kilometres. Some modern vehicles with advanced automatic transmission systems and synthetic fluids may have longer intervals of up to 160,000 kilometres or more. For manual transmissions, the change interval can vary, especially if the vehicle is not subjected to severe driving conditions.

If a vehicle is frequently driven in harsh conditions such as heavy traffic, towing, off-road, extreme temperatures, or mountainous terrain, the transmission fluid may need to be changed more frequently. Severe conditions put additional stress on the transmission and accelerate fluid degradation. Under normal driving conditions, following the manufacturer’s recommended interval may be sufficient.

Regular checks based on your car’s manual and professional inspections during routine maintenance will help ensure your vehicle’s transmission fluid is changed at the appropriate intervals. Working with a trusted auto repair shop can help you keep your car’s transmission functioning properly.