Do I need to service my Automatic transmission?

First, a little bit about your automatic.

Your vehicle’s transmission has a tough job. The main task is transferring power that is created by the engine to the wheels in order to drive the vehicle forward. This is done by transferring the power of the engine through a Torque Converter (a fluid coupler) to the input shaft of the transmission, through the planetary gear train and finally to the output shaft which is connected to the driveshaft, then to a differential which transfers the power to the wheels. In front wheel drive vehicles the differential is internal in the transaxle.

This transfer of power creates heat and this is the automatic transmissions biggest enemy. The greatest cause of heat is the torque converter. This is controlled in newer automatics by the use of a lock converter, an internal clutch that engages at higher speeds and eliminates slipage.


What is an Automatic Transmission Service?

According to ATRA, The automatic Transmission Rebuilders Association. A transmission service is part of your routine maintenance, just like replacing your engine oil. New fluid restores the holding power between the clutches, reducing slip and heat production. At the same time, flushing the old fluid washes away tiny particles of clutch material and metal shavings

A complete transmission service should include:

• removing and examining the sump or pan (where possible)

• replacing or cleaning the screen or filter

• cleaning the pan

• reinstalling the pan with a new pan gasket

• replacing the old fluid with new, high quality ATF

• adding a friction modifier or additive package (model specific)

New fluid restores the holding power between the clutches, reducing slip and heat production.

 At the same time, flushing the old fluid washes away tiny particles of clutch material and metal shavings. Those particles clog passages and wedge between moving parts, causing wear throughout the transmission. Changing the fluid eliminates those particles and the wear they cause.


Why should I service my automatic?

Transmission fluid services are an important part of regular maintenance and will increase the service life of your transmission. According to the ATRA, 90% of automatic transmission failures are caused by overheating and can be often blamed on transmission fluid that should have been replaced.

Like other vital automotive fluids, transmission fluid deteriorates over time. Hard use — such as frequent stop-and-go city driving, hauling heavy loads, trailer towing — will accelerate the deterioration. That kind of driving raises the operating temperature of the transmission, and heat puts more strain on the transmission and the fluid, which helps facilitate gear shifts, cools the transmission and lubricates moving parts.

Transmission fluid often is red but can come in other colors, and as it deteriorates it tends to turn darker. It may also acquire a burned odor that could indicate it needs to be changed or that the transmission is developing mechanical problems. Another indication it needs changing is dirt or other debris in the fluid.

The net result of changing the fluid is to provide better lubrication, improved the holding ability of the friction components, and reduced heat. So your transmission works better for years longer, which means you’re less likely to face a major transmission repair.


What will happen if I don’t have my transmission serviced?

The fluid will begin to deteriorate.

Just as the engine uses oil to prevent the interior motor part from rubbing together with excessive friction, the transmission uses a specialized fluid that does just the same. As this fluid ages it collects impurities and begins to gunk up, thus losing its ability to do what it is designed to do.

The transmission my lag

Another reason you always want to keep up with transmission service is to ensure that it shifts smoothly. This is particularly true with automatic transmissions. An automatic transmission that has not been serviced may begin to lag, meaning there will be a delay while it shifts. If this occurs you will notice your engine RPMs spike as the transmission shifts. This should not occur. Be sure to get to the repair shop as soon as possible for service.

The transmission may fail completely

Like any mechanical system that requires maintenance, it will fail if it is not serviced. A failed transmission will require a complete rebuild or replacement, both of which can be very expensive. Be sure to have your transmission serviced to prevent transmission failure.


The recommended service interval


Many companies that rate vehicles, base their recommendations on the published maintenance schedule. Manufacturers know this and intentionally extend their service recommendations. This makes costs appear lower. This is not in the best interest of people that keep vehicles a long time. For instance, recommending an automatic transmission service at 100,000 miles appears to cost half as much as recommending 50,000 miles. The problem is, the odds of a problem increase drastically at higher mileage, when we fail to service our automatic transmission in a timely fashion.

The overall lowest cost is to replace the fluid and if possible the filter, before use completely depletes them. A proper automatic transmission service at 40,000 miles may prevent the need to rebuild the automatic transmission at 120,000 miles. Under severe condition, such as towing, a 30,000 mile interval is better. The same is true with automatic transmissions that have non replaceable filters.


Here at London’s Automotive our goal is to prolong the life of your vehicle and reduce the incidence of costly breakdowns and repairs. Regular preventative maintenance is the key to making this happen. While we understand that the manufacturers are consistently extending the service periods we feel that for most vehicles 30,000 miles, and for some 50,000 miles are the best interval to get the maximum service life from your automatic transmission.