Transmission Fluid
Transmission fluid is a greasy liquid that serves as a lubricant for all mobile components within a vehicle’s transmission. In an automatic transmission, the fluid acts as a coolant and carries power from the engine to the transmission as well. Various fluids are used depending on the style of transmission. Automatic transmissions simply use automatic transmission fluid. On the other hand, manual transmissions may operate with motor oil, heavyweight hypoid gear oil, or rarely, automatic transmission fluid. You can find out what your vehicle’s transmission uses by looking in the owner’s manual.
Should I have my transmission fluid replaced when the service is recommended?
Yes. It doesn’t matter if the vehicle you’re dealing with has a manual or automatic transmission.
- Manual: According to most car manufacturers, manual transmission fluid should be flushed and replaced every 30,000 to 60,000 miles. Under strenuous use, some recommend that it should be changed every 15,000 miles.
- Automatic: Depending on the make of the vehicle, automatic transmission fluid may need to be changed once every 30,000 miles, but some do not ever require that it be switched. Generally, most vehicles call for a renewal of automatic transmission fluid between 60,000 and 100,000 miles, but performing this procedure more often will not cause any damage.
Why is it necessary to change the transmission fluid?
- Manual: The difficulty with manual transmission is not so much the deterioration of the fluid as it is the contamination of it. The fluid becomes infiltrated with the metal particles of synchronizers, bearings, and gears as these components become worn down. Obviously with these tiny foreign objects floating around in the fluid, it can’t lubricate as effectively as clean oil. The life of your vehicle’s transmission will decrease if these pollutants are not flushed out.
- Automatic: Since extensive heat is a byproduct of an automatic transmission, the quality of the fluid lessens over time due to high temperatures. Similar to manual, microscopic pieces of metal will contaminate automatic transmission fluid and also shorten the life of the transmission if they are not released.
What happens if I don’t change the transmission fluid as directed?
As mentioned previously, if you allow your transmission fluid to deteriorate and become impure, you will essentially be lubricating the transmission with flakes of metal. As a result, the transmission will eventually fail and have to be rebuilt or replaced. This procedure is a financial setback no matter how you look at it, and it can be easily avoided.
Should I be concerned with any maintenance in between scheduled service?
Yes. It is vital to check transmission fluid level in between scheduled tune-ups. If a vehicle that is low on transmission fluid is driven, the transmission may shift haphazardly or not even shift gears at all. Low transmission fluid also means the various elements inside the transmission will not be lubricated properly. It is likely that you will not even hear any warning signs to alert you of a problem with the transmission. Without any hint that the transmission is lacking fluid, you won’t be aware of a serious problem until it’s too late. This should be reason enough to get it checked occasionally.
Check the transmission fluid yourself
- Manual: It can be a daunting task to check the fluid of a manual transmission. Some manufacturers will provide a dipstick for this purpose, but the majority do not. If your car has a manual transmission, it is probably easiest to ask a mechanic to check the transmission fluid levels during routine service like an oil change. It shouldn’t be a hassle for them because it is a quick process.
- Automatic: If you have a vehicle with an automatic transmission, it will come with a dipstick. Make sure you don’t mistake the crankcase dipstick for the transmission dipstick. The most common method of checking automatic transmission fluid is to remove the transmission dipstick while the car is idle, and the engine is warmed up. The transmission must be in the “park” position as well. Since every car is not built the same, consult your owner’s manual in case your car has a different system
Quick tip
Transmission fluid will never combust like motor oil, so anytime an automobile is low on transmission fluid, there is probably a leak.