MAINTENANCE - Automatic Transmission Maintenance some truck applications — such as the stop-and-go conditions of CITY DELIVERY, or the hauling of heavy loads and trailer use associated with many VOCATIONAL and highway applications — will increase this peak operating temperature, and hasten the break down of the transmission lubricant. Automatic Transmission Maintenance NOTE If vehicle application changes signifi- cantly, the vehicle should be re-evalu- ated for a new peak operational tem- perature, and if necessary, observe the maintenance intervals associated with the new peak temperature.
An automatic transmission is a complex and expensive vehicle component requiring operational attention and proper maintenance to ensure long-lasting performance. This performance is impacted greatly by the quality of its lubricating fluid, which reduces friction between its many parts, facilitates gear shifting, and cools down the transmission components. The chief factor that affects the durability of a lubricating fluid is temperature. When the operating temperature of the transmission increases, this fluid begins to break down, degrading its lubricating properties.
Without proper lubrication, friction between components increases, breaking them down and building up sludge in the transmission. This will eventually result in transmission failure, requiring it to be replaced. A transmission's peak operating temperature can be defined as its maximum general operating temperature and is determined by how the transmission is used. The "hard use" associated with Therefore, it is essential that proper lubrication maintenance is performed for the operational temperature specific for your transmission use. Once the peak operating temperature is known, the appropriate maintenance tables can be observed.
If the peak operating temperature has not been determined, assume the 95єC peak operating temperature intervals. Unlike engine oil, transmission fluid serves as both a lubricant and a hydraulic fluid. The hydraulic pressure needed to shift gears smoothly (and avoid gear slippage) requires that the operator maintain transmission fluid in the proper range (see How to Check Transmission Fluid on page 23). The operator should check their transmission fluid regularly, required as part of their weekly checks (see Weekly Checks in your chassis operator's manual).
5 Operational temperature data for this transmission can be collected by your PACCAR Powertrain distributor technician early in the truck's life (collected during the first 5,000 miles of operation (see First 3,000 – 5,000 mi interval)). The value of this data will depend on whether this early temperature data – which is based on truck application – is representative of how the vehicle will be used for the life of the truck. Y53-1331 (6/21) 29