Checking the transmission fluid daily
Adjusting the shifting and kickdown linkages
Adjusting lockup bands
Changing the transmission fluid and filter at recommended service intervals

Checking the Fluid
The operator is responsible for first echelon (operator's) maintenance. The operator should not only be trained to know to look for the proper fluid level but also know how to look for discoloration of the fluid and debris on the dipstick.

Fluid levels in automatic transmissions are almost always checked at operating temperature. This is important to know since the level of the fluid may vary as much as three quarters of an inch between hot and cold.

The fluid should be either reddish or clear. The color varies due to the type of fluid. (For example: construction equipment using OE-10 will be clear). A burnt smell or brown coloration of the fluid is a sign of overheated oil from extra heavy use or slipping bands or clutch packs. The vehicle should be sent to the shop for further inspection.

CAUTION
Not all transmission fluids are the same. Before you add fluid, check the manufacturer's recommendations first. The use of the wrong fluid will lead to early internal parts failure and costly overhaul.

Overfilling the transmission can result in the fluid foaming and the fluid being driven out through the vent tube. The air that is trapped in the fluid is drawn into the hydraulic system by the pump and distributed to all parts of the transmission. This situation will cause air to be in the transmission in place of fluid and, in turn, cause slow application and burning of clutch plates and facings. Slippage occurs, heat results, and failure of the transmission follows.

Another possible, but remote, problem is water, indicated by the fluid having a "milky" appearance. A damaged fluid cooling tube in the radiator (auto-motive) or a damaged oil cooler (construction) could be the problem. The remedy is simple. Pressure-test the suspected components and perform any required repairs. After repairs have been performed, flush and refill the transmission with clean, fresh fluid.

Linkage and Band Adjustment
The types of linkages found on an automatic transmission are gearshift selection and throttle kick-down. The system can be a cable or a series of rod and levers. These systems do not normally present a problem, and preventive maintenance usually involves only a visual inspection and lubrication of the pivot points of linkages or the cable. When adjusting these linkages, you should strictly adhere to the manu-facturer's specifications.

If an automatic transmission is being used in severe service, the manufacturer may suggest periodic band adjustment. Lockup bands are always adjusted to the manufacturer's specifications. Bands are adjusted by loosening the locknut and tightening down the adjusting screw to a specified value. The band adjusting screw is backed off a specified amount of turns and the locking nut tightened down. NOT ALL BANDS ARE ADJUSTABLE. Always check the manufacturer's service manual before any servicing of the transmission.

Fluid Replacement
Fluid replacement is to be performed according to the manufacturer's recommendations. These recom-mendations vary considerably for different makes and models. When you change automatic transmission fluid, always read the service manual first. Service intervals depend on the type of use the vehicle receives. In the NCF, because of the operating environment, more than a few of the vehicles are subjected to severe service. Severe service includes the following: hot and dusty conditions, constant stop and go driving (taxi service), trailer towing, constant heavy hauling, and around the clock operations (contin-gency). Any CESE operating in these conditions should have its automatic transmission fluid and filter changed on a regular schedule, based on the manufacturer's specifications for severe service. Ensure the vehicle is on level ground or a lift and let the oil drain into a proper catchment device.

The draining of the transmission can be accomplished in one of the following three ways:

1. Removing the drain plug
2. Loosening the dipstick tube
3. Removing the oil pan

CAUTION
Oil drained from automatic transmissions contains heavy metals and is considered hazardous waste and should be disposed of according to local naval station instructions.

Once the oil is drained, remove the pan completely for cleaning by paying close attention to any debris in the bottom of the pan. The presenceofa high amount of metal particles may indicate serious internal problems. Clean the pan; set it aside.

All automatic transmissions have a filter or screen attached to the valve body. The screen is cleanable, whereas the filter is a disposable type and should always be replaced when removed. These are retained in different ways: retaining screws, metal retaining clamps, or O rings made of neoprene. Clean the screen with solvent and use low-pressure air to blow-dry it. Do not use rags to wipe the screen dry, as it tends to leave lint behind that will be ingested into the hydraulic system of the transmission. If the screen is damaged or is abnormally hard to clean, replace it.

Draining the oil from the pan of the transmission does not remove all of the oil- draining the oil from the torque converter completes the process. To do this, remove the torque converter cover and remove the drain plug, if so equipped. For a torque converter with-out a drain plug, special draining instructions may be found in the manufacturer's service manual. Before performing this operation, clear it with your shop supervisor.