Commonly Overlooked Maintenance Items 2

Last month we talked about engine coolant, this month we will talk about transmission fluid. There are two types of transmissions, a manual and an automatic. The two have different requirements for maintenance and I will explain those this month.

An automatic transmission’s fluid performs three different jobs. The first is shifting the gears. Automatic transmissions rely on this fluid to help it shift the gears up and down depending on vehicle speed and engine speed. I won’t go in to detail on how an automatic transmission works at this time.

The second job of automatic transmission fluid is cooling. One of the worst enemies of an automatic transmission is heat. The fluid is used to cool the transmission by flowing it through a transmission cooler. The transmission cooler is either in the vehicles radiator or is a separate radiator like device.

The last job of automatic transmission fluid is lubrication. Just like engine oil, the transmission fluid lubricates the gears and other mechanisms in the transmission.

The fluid in a manual transmission primary job is lubrication. Although it also helps dissipate heat, manual transmissions do not generate as much heat as automatics. An automatic generates more heat due to the torque converter.

Transmission fluid should be changed every 50,000 miles or every 3 years. This is subjective to the vehicle also. You should at least follow the manufacturer’s recommendations.

So what can you do to help the transmission fluid do its job? Of course changing it when the time comes is number one, but there are a few others. These are primarily for automatic transmissions. Since heat is the number one enemy of an automatic transmission, installing an auxiliary cooler is recommended. This can reduce transmission temperature by 50 degrees or more in some cases. There are a few different transmission coolers available. They come in different shapes and sizes. Some have fans on them to help with additional cooling. The best location for mounting these is in front of the radiator. The inlet should be plumb to the line out on the radiator. And the line out on the auxiliary cooler should go back to the transmission. Plumbing it the other way will introduce heat from the radiator.

Another item to help reduce heat is a deeper fluid pan. The best pans are ones that have cooling fins built in. The fins act as a heat sink to draw heat from the pan. This works well when the vehicle is moving.

The last item to extend the life of the fluid is using a remote filter adapter. Almost all automatic transmission filters are inside the pan. The only way to change it is by removing the pan and emptying the transmission fluid. Installing an extra filter is a great way to help extend the life of the transmission. These install in between the transmission and the cooler using the transmission cooler lines. These use standard oil filters and can be changed when you change your oil.

There are a few ways to test transmission fluid to see if it needs changed before the recommended interval. The first is by looking at it. Pull the dipstick and look at the color of the fluid. The fluid is usually red by color and if it is black, it needs to be changed. You can also use a white paper towel to get a better look at the color. Just let some of the fluid drop off the end of the dip stick onto the paper towel. The second sign is by smell. If it produces a strong, burnt odor, then it is time to change it.

Running your transmission with “burnt” fluid will cause the transmission to slip. This will then cause the transmission to produce more heat and heat will kill the transmission.

Now you know a little more about the reasons why it is a good idea to monitor your transmission fluid and ideas on how to extend the life of the fluid. Next month we will talk about brake fluid. As always, if you have any questions, please let me know. We are also looking for ideas on up coming articles so if you have any, send them to me.

Vincent Wright
sales@kmwperformance.com
http://www.kmwperformance.com