Description:
7 min
The oil in an automatic transmission, or ATF, performs several functions:
• It removes heat from heated parts,
• It lubricates bearings,
• It serves as a working fluid for the hydraulic control system and torque converter.
The automatic transmission functions properly when the oil has specific lubricating properties and viscosity, such as 2000 mPa at a temperature of 20 °C. ATF cannot retain its properties indefinitely and needs to be changed periodically.
How often should you change the oil in an automatic transmission?
It is crucial to change the oil in the automatic transmission on time since the correct operation and durability of your gearbox depend on it. The owner's manual for your car should provide the recommended intervals for automatic transmission oil changes. Let's consult the manual first! Only the engineers who designed your gearbox know the ideal interval for oil changes.
On average, the oil should be changed every 50,000 miles (80,000–90,000 kilometers). Many dealerships recommend more frequent oil changes than the manufacturer's recommendation. To summarize the advice, changing the oil every 35,000 miles (60,000–80,000 km) ensures proper functioning of the gearbox.
Under severe operating conditions, many manufacturers recommend changing the oil in automatic transmissions twice as often. Pay close attention to this! Severe operating conditions for automatic transmissions include:
• Towing cars and trailers, transporting goods, or carrying many passengers, which adds a load to the gearbox.
• Driving on roads with dirt, sand, and snow cover.
• High ambient temperature that causes box overheating and faster oil aging.
• Low temperatures, frost, or thickened oil.
• Frequent start-stop modes, traffic jams, and urban traffic conditions.
• Wheel slip, such as getting stuck in the woods or on the beach.
• Sharp acceleration from a standstill.
You can check the condition of the oil yourself. Simply pull out the dipstick - the oil should appear light. If it is excessively dark or has an unpleasant burning smell, visit a service station.
Some transmission problems can indicate low oil levels or old ATF. Here are the most common ones:
• Low oil pressure in the line.
• Slippage when shifting gears.
• Transmission slipping and downshifting on long hills in the last gear.
• The car does not move in either reverse or forward.
• Inability to shift from P or N to any speed.
• A push sensation when turning at any speed, with the car not moving.
Keep in mind that each of these problems may have other causes. For example, low oil pressure in the line can result not only from low oil levels but also from a faulty dump valve in the oil pump, dirty solenoids, or valve body.
How to check the oil level in an automatic transmission?
If the oil level is low, the gearbox will not function correctly, and you will need to add the necessary amount of ATF. To check the level, follow these steps:
1. Locate the dipstick, which is typically under the car's hood. The engine oil dipstick is usually yellow, while the automatic transmission oil dipstick is red.
2. Check the ATF level when the gearbox is warm. Start the engine and drive for 6-9 miles (10-15 km) in the "Drive" position of the automatic transmission. Then, park the car on a level surface and shift the selector lever to the "P" (Parking) position. Let the engine idle for an additional 2-4 minutes.
3. With the engine running, remove the automatic transmission oil dipstick and wipe it dry with a lint-free cloth. Insert the dipstick back into the tube, hold it there for 4-5 seconds, and then pull it out.
4. The dipstick will have two zones, and you need to look for the "Hot" mark. The oil level should be between the maximum and minimum notches, approximately in the middle. If the oil exceeds the maximum mark of the Hot zone, it is overfilled. If it is below the minimum mark, you need to add ATF.
5. In some vehicles, the oil level is checked differently. For example:
- In BMW automatic transmissions, most Volkswagen and Audi models, the level is visible through a viewing window, and there is no dipstick. You will need a lifter to check the ATF level.
- Dodge, Hyundai, Jeep, Mazda, Mitsubishi, Volkswagen, and Audi models require setting the gear to "N" (Neutral) for checking the oil level.
- In Honda vehicles, the automatic transmission oil level should be checked with the engine off.
How to change the oil in an automatic transmission?
The oil in an automatic gearbox can be changed through partial or complete replacement. Here are step-by-step instructions for partial replacement:
1. Prepare everything you need in advance, including new oil, a small funnel, and an empty measuring container for the drained oil.
2. Unscrew the drain plug located at the bottom of the automatic transmission crankcase.
3. Place a measuring container beneath the drain plug and wait for the oil to drain completely.
4. Note the amount of oil that has drained out; you will need to refill the same amount.
5. Use a small funnel to pour ATF into the automatic transmission through the dipstick tube.
6. After adding the oil, check the oil level. If it is insufficient, add more oil. If it is excessive, drain the excess through the drain plug.
What kind of oil to use in an automatic transmission?
Always refer to the operating instructions for your car. The manufacturer of your vehicle knows the exact type of oil required for your gearbox. Do not rely on advice from forums or individuals suggesting alternative fluids to save money. Incorrect selection of fluid can lead to breakdowns or malfunctions in the automatic transmission. Follow these guidelines:
1. If the manual specifies Dexron II, you can use Dexron II or its subsequent substitutes, such as Dexron IIE or Dexron III.
2. If Toyota Genuine ATF type T-IV is recommended, it is advisable to use it or compatible fluids that meet or exceed the requirements of type T-IV, according to the oil manufacturer.
3. There are original OEM fluids that are 100% suitable for your gearbox. If you are unsure about the range of oils and specifications, it's best to use the recommended original ATF.
4. Here are examples of OEM fluids for automatic transmissions:
- GM: DEXRON®-
II, DEXRON®-III, DEXRON®-VI
- Ford: MERCON®, MERCON®-V
- Toyota: T, T-III, T-IV, and WS
- Honda: Z1, DW-1
- Hyundai/Kia/Mitsubishi: SP-II, SP-III, SP-IV, Red-1
- Nissan: Matic D, J, K, and S
- Mazda: M-III, M-V
- Mercedes Benz: 236.1/.2 /.3/.5 /.6/.7/.9/.10/.11
- Saab: 93 165 147
- Saturn: Saturn ATF
- Subaru: Subaru ATF, ATF-HP
- Suzuki: 3314, 3317
- BMW: 7045E, LA2634, LT71141, P/N 83 22 0 142 516
- Allison: TES-389 and C-4
- Caterpillar: TO-2
- Chrysler: ATF+3®, ATF+4®
Remember that OEM fluids are not produced by the car manufacturer or your automatic transmission manufacturer. They are produced by oil manufacturers who also produce regular branded oils. If you are unsure, non-original oils are often cheaper, but it's essential to ensure they meet the necessary specifications.
Multipurpose oils in automatic transmissions:
For example, Valvoline promotes their Valvoline Maxlife ATF product with the following claims and approvals:
Satisfies / Has approvals:
- GM Dexron IID, IIE, III, VI
- Ford Mercon, Mercon V
- Allison C-4, TransSynd*, TES-295
- BMW LT 71141, LA 2634
- MAN 339 type Z1, Z2, V1, V2
- Mazda*, Mini Cooper* CVT EXL 799
- Toyota T, T-11, T-IV
- Chrysler* ATF+3
- Mitsubishi* Diamond SP-II, SP-III
- Honda ATF-Z1
- MB Approval 236.1,2,3,5,6,7, 8,9,10,11
- Nissan* D, J, K,-matic
- Volvo 1161521, 1161540
- Audi* G-052-0250-A2, GM9986195
- ZF-TE-ML-14B, 16L, 17C, JWS 3309
- Voith* G 607, 1363
- KIA* SP-II, SP-III
- Suzuki*
- VW TL 52162
- and others
Valvoline, being a reputable manufacturer with authority in North America and Europe, states these approvals. Their reputation is at stake, so such a versatile claim implies that the oil in the automatic transmission offers exceptional performance and meets the requirements of various automatic transmission manufacturers.