December Tech Minute: Transmissions & Differentials Maintenance

This month I’d like to take a few moments to talk about filters and some service tips to keep in mind while performing a PM. The filter industry has come a long way in Building filters that not only extend drain intervals but filter finer particles while maintaining acceptable pressure drop. The choice of filter brands, media type, cost, and availability are enough to make any fleet manager take to drinking.

We all have our favorite brands which usually develop from seeing the results through the years. Ask any old school driver what his favorite oil is? He will probably say Shell Rotella T before you finish your question. When customers ask; which oil is the best? My advice is to use one of the big three oils and stick with it. I’ve seen enough engine failures that in my opinion brands of oil does not matter; filter choice and consistency in service make the difference. Ensure your intervals are within the OEM guidelines by focusing on fuel burn and duty cycles. Using engine hours instead of mileage is one way to make sure you schedule maintenance on time. Especially if your fleet has PTO’s or excessive idel time. Choosing the best filter brand is a tough choice but recommending the OEM filter is always a safe bet. OEM filters are cost-competitive with the aftermarket and ensure that the right specs are being used when filters are replaced. 

Today’s high fuel pressures demand tight tolerances; secondary fuel filters are filtering between 2 and 4 microns. Oil filters generally filter down to 10 microns. A micron can be defined as a unit of length equal to one-millionth of a meter with a human hair measuring around 100 microns. Utilizing proper service practices such as; not filling filters on the clean side and keeping the plastic on the filter until installation are crucial for engine life. During air filter service there are many important practices, such as; wiping the inside of the filter housing with a damp cloth keeps the dust out of the air intake during service events. Another practice is utilizing the air filter minder to judge when air filters need to be serviced. As air filters collect dust and dirt, they become more efficient and over-servicing can lead to shorter engine life. One other failure we have seen is on the external style air cleaners, the inner portion of the filter is the dirty side. Any dirt or debris that falls into the can or if the gasket isn’t replaced during service events allows dirt to get sucked up into the engine. The air dryer cartridge and power steering filter carry the same interval. Severe duty calls for replacement every six months while linehaul is every twelve months. Using quality dryer cartridges keeps moisture out of the air tanks and leads to longer brake component life. If your fleet is running extended life coolant make sure you are using a blank filter, ELC requires no SCA’s. DEF filters on pre-2017 units are replaced every twelve months after 2017 DEF filters get replaced at 6000 engine hours or 200k miles. These filters are under the truck, clean the housing of road dirt before removing the filter element to ensure no contamination of the pump occurs. I hope you find this info useful.