Transmission Preventive Maintenance

Automatic transmission fluid plays a key role in extending transmission life.

Just a few decades ago, many European and Asian import vehicles incorporated variations of the mechanically controlled Borg-Warner automatic transmission. Today, imported vehicles use a full range of diverse computer-controlled automatic transmissions. A simple count of the pan gasket configurations on a transmission filter application chart gives a clear idea of the market's diversity. The manual transmission market has grown in much the same way. When it comes to automatic and manual transmission service, most shops today choose to focus on fluid maintenance and external adjustments, leaving internal repairs and rebuilds to transmission specialists.
Import transmissions have a reputation for being very reliable, complicating the task of developing a failure profile analysis. For all but the high volume shops specializing in a particular nameplate, it's almost impossible to develop the experience necessary to diagnose, estimate and repair specific transmission failures.
Due to increased transmission reliability, customers and service writers often ignore transmission service. However, transmissions still wear out and break, and the repairs can be quite expensive. As a result, preventive maintenance is an important issue.
The condition of the automatic transmission fluid plays an important role in extending transmission life. The fluid's color, odor and opacity provide clues to whether the fluid, or fluid and filter, requires changing. Although a color change from red to straw color can usually be attributed to normal aging, a brown color indicates oxidation or particulate contamination from worn clutches and bands. Black or heavily oxidized fluid indicates slippage of another transmission failure.
Opacity is the clearness of the fluid. Use the fingerprint test to determine the cleanliness of used automatic transmission fluid. Simply place a drop of fluid on a fingertip. If the fingerprint is not visible through the fluid, it should be changed. Water contamination has a large effect on fluid viscosity and opacity, with the fluid becoming more viscous and opaque as contamination increases.
Some Fluid has a burned smell, but this odor is relevant only if the fluid is opaque, brown or blackened.
Manual transmissions still comprise a sizeable portion of the import market. An early sign of failure is a loss in shift quality. Gear engagement may become more difficult, or the transmission may grind during gear changes. Other failures involve excessive noise from worn bearings, low fluid level and worn or mis-matched gear teeth.
The first step to diagnosing the problem is clutch evaluation. Whether cold or hot, it should engage smoothly and release cleanly. Engaging the reverse gear when the clutch pedal is depressed shows whether the clutch release is clean and complete. If reverse gear grinds, the clutch mechanical or cable linkage may require adjustment. For a hydraulic clutch linkage, the master and slave cylinders may require bleeding or replacement.
If shifting a manual transmission is difficult in cold weather conditions, the wrong transmission fluid may be installed. If gear clash arises during downshifting, it is likely due to worn gear synchronizers. If the gearshift binds between gears, it is likely the internal shift forks came loose from the shifting rods of rails. If transmission noise gets worse as oil temperature rises, it may be caused by rough transmission bearings.
If an automatic transmission is equipped with a magnetic particulate trap, evaluate the quality and quantity of the debris. Large collections of iron particles may indicate worn internal gear parts. Most manual import transmissions feature magnetic check and drain plugs, and they should be examined for excessive steel and iron particles. Small amounts are a normal part of the gear break-in or wearing process.
AMSOIL Synthetic Universal Automatic Transmission Fluid is a premium quality ATF formulated to exceed the performance requirements of domestic and foreign automatic transmission fluids, providing smooth shifting, superior wear protection and outstanding performance for extended drain intervals.
AMSOIL Synthetic Manual Transmission and Transaxle Gear Lube is designed to provide superior protection for synchronized manual transmissions and transaxles. Formulated with extreme pressure additives and advanced synchromesh qualities, Synthetic Manual Transmission and Transaxle Gear Lube provides smooth shifts while protecting gears, bearing and seals.
AMSOIL Synthetic Synchromesh Transmission Fluid is specifically designed to provide superior protection for manual transmissions and transaxles with synchromesh systems. Formulated with advanced additive technology, Synthetic Synchromesh Transmission Fluid Provides proper friction characteristics for smooth shifting without grinding or bump shifting.