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Transmission Fluid Change: Full Guide + Tips
Key takeaways:
- Transmission fluid is critical for performance and protection—it lubricates components, manages heat, prevents leaks, enables smooth shifting, and keeps contaminants at bay.
- Service intervals vary by transmission type and driving conditions.
- DIY transmission fluid changes are possible for many vehicles. However, sealed transmissions may require professional service.
Although transmission fluid changes occur at a less frequent maintenance interval than most service recommendations, they’re still a vital part of vehicle care. A transmission breakdown can mean costly repairs, a complete rebuild, or even a full replacement.
The comprehensive guide below includes everything you need to know about transmission fluid changes, including when and how to do one yourself.
How Does Transmission Fluid Help Your Car Function?
Many types of automotive transmissions exist, including automatic and manual transmissions, continuously variable transmissions (CVTs), and dual-clutch transmissions (DCTs). Fresh transmission fluid appears red and slightly translucent.
Transmission fluid performs the following functions:
- Lubricates the transmission’s internal components, including shafts, bearings, and gears, to prevent excessive wear
- Dissipates the heat built up during continued use to prevent overheating and fluid degradation
- Flows through the transmission cooler to further remove heat from the transmission and maintain optimal operating temperature
- Maintains proper pressure to keep seals intact and prevent leaks
- Contains friction modifiers that promote smooth shifting
- Removes contaminants
- Drives the torque converter
When the transmission fluid begins to degrade, the protective film between internal components wears away, allowing metal-to-metal contact. In addition, changes in the fluid’s composition due to contaminants or excessive heat can also damage the pump and cause it to fail.
Transmission failure can easily sideline your vehicle and rack up significant repair bills if left unchecked.
When To Schedule a Transmission Fluid Change
Consult your owner’s manual to determine when to perform a transmission fluid change. Generally speaking, most manual transmissions require a fluid change every 30,000 miles to 60,000 miles, while automatic transmission fluid lasts anywhere from 60,000 miles to 100,000 miles.
Under normal driving conditions, exchanging your vehicle’s transmission fluid every five years can also help maintain its longevity.
Your vehicle may also present several signs that indicate it’s time for a transmission fluid change, including the following:
- Transmission service light
- Check engine light
- Degraded transmission fluid that appears dark-colored
- Burnt transmission fluid
- Poor transmission performance, including slips, rough shifts, and noise
Exact transmission fluid change intervals depend on several factors, including the climate, vehicle make and model, and frequency of use. If you frequently use your vehicle for towing or off-road activities, your transmission has to work harder. Decrease the time between transmission fluid changes accordingly.
How To Change the Transmission Fluid
Some modern vehicles come from the factory with sealed transmissions, making changing the fluid yourself more difficult since you need special tools. However, most older vehicles still allow you to access the transmission to drain the fluid. Follow the steps below to perform your own transmission fluid change.
1. Start and Lift Your Vehicle
Start your vehicle and bring it up to operating temperature. Transmission fluid drains best when hot, but it can also be a safety hazard if you’re not careful. Drive your vehicle onto a lift or raise it to access the undercarriage.
2. Drain the Old Transmission Fluid
Place a tarp and a drain pan underneath the transmission pan. Then, start loosening the bolts holding the pan on. Note that the transmission fluid will drain out at the lowest point of the pan due to gravity, so choose the bolts you loosen accordingly.
3. Inspect and Clean the Transmission Pan
Once you’ve drained the transmission fluid completely, remove the remaining transmission pan bolts and inspect the pan’s interior. Many transmission pans have a small magnet on the inside that collects metal debris. If larger pieces are stuck to this magnet, further transmission inspection may be necessary to determine if anything is broken or damaged.
4. Install the New Transmission Pan Gasket
Clean the transmission pan with a degreasing agent and dry the surface, removing any lint or dirt. Replace the transmission pan gasket and the filter. Use RTV sealant to promote a proper seal.
5. Reinstall the Pan and Torque the Pan Bolts
Lift the pan and reinstall the bolts holding it on. Tighten the bolts to the recommended torque specifications, which can typically be found in your owner’s manual.
6. Add New Transmission Fluid
If your transmission has a dipstick opening, use it to fill up the transmission with new fluid. If not, you’ll need a fluid extractor to replace the fluid. Ensure you use the proper fluid for your vehicle, and avoid under- and over-filling the transmission.
7. Circulate the New Fluid and Check for Leaks
Start your vehicle and lower it to the ground. To prevent the car from hitting nearby obstructions, take care to keep your foot on the brake at all times and shift the transmission into drive, reverse, and park, pausing briefly in each gear. Repeat this process a few times to circulate the fluid.
Put your car in park and turn off the engine. Remove the transmission dipstick and check the fluid levels, adding any necessary fluid. Once you’ve achieved the proper fluid level, repeat the shifting process described above, then check beneath your vehicle for leaks.
What Transmission Fluid Does My Car Need?
Previously, Dexron/Mercon and Ford Type F were the only transmission fluids on the shelf. However, there are more than two dozen variants to select from today. Most automotive manufacturers produce and recommend their own formulations, which is a good place to start if you’re unsure which transmission fluid type to use.
Many well-known automotive brands produce transmission fluids that meet OEM specifications and incorporate additional additives or features. For example, Valvoline offers several types of transmission fluid for automatic, CVTs, manual, and hybrid vehicle transmissions. Other popular brands include Castrol, Mobil 1, and Royal Purple.
Up-Shift to Better Transmission Maintenance and Care
Whether you perform a transmission fluid change on your personal vehicle or your fleet of service vehicles, it pays to maintain your vehicle with premium transmission fluid sourced from trusted partners like Cadence.
Call us at 336-629-2061 for guidance in selecting the best transmission fluid for your needs.
FAQs
How often should I change my transmission fluid?
Most manual transmissions need a fluid change every 30,000-60,000 miles, while automatics typically last 60,000-100,000 miles. Always check your owner’s manual, and shorten intervals if you tow, drive off-road, or operate in extreme conditions.
What are the signs that it’s time for a transmission fluid change?
Warning indicators include the transmission or check engine light turning on, dark or burnt fluid, poor shifting performance, slipping gears, or unusual noises.
Can I change my own transmission fluid?
Yes. If your vehicle isn’t sealed, you can perform a fluid change yourself by draining the old fluid, replacing the filter and gasket, adding new fluid, and checking for leaks. Sealed transmissions usually require special tools and professional service.
Sources:
NACFE | Automated Manual Transmissions
Dual Clutch Control | Clemson Vehicular Electronics Laboratory