Where Did The Dipstick Go?

24 10 2013

Dale BertramBack in the day we checked transmission fluid by pulling the dipstick out. We could tell many things by that dipstick but today it isn’t that simple. Many new models don’t even come equipped with a dipstick!

Automatic transmissions have become marvels of precision and durability in recent years. Many are “factory sealed” and do not have a dipstick tube to allow checking/adding to the fluid level. Some of these transmissions are filled with “lifetime” fluid that does not require changing, while others only require fluid service at very long intervals that are often greater than 100,000 miles.

Vehicles with sealed transmissions run the gamut from a Chevrolet Cavalier to the Toyota Highlander. This is all good for the consumer – one less thing on the car to worry about – but for the service facility, it presents a conundrum. The actual procedure (specified by factory service instructions) to check fluid level on these sealed transmissions can be quite involved, requiring a narrow temperature range for the transmission fluid, and a sophisticated scan tool to read the fluid temperature. The factory service procedure for checking the transmission fluid level on a 2008 Toyota Highlander Hybrid is 14 pages long!

Many service providers do not have the time or specialized equipment readily available to check and adjust fluid levels on sealed transmissions from a variety of manufacturers. Straying from a manufacturer’s service procedures and removing a fluid plug to check the fluid level could even unintentionally create a new service issue. If a sealed transmission does not have any visible external leaks, it is reasonable to assume the fluid level is the same as when the factory filled it. On most sealed transmissions, “the fill, check, and drain plugs” are typically marked with a durable paint during final assembly. This makes a clear visual indication if they are ever removed.

Service providers should take care not tell a consumer that transmission fluid was “checked” unless the proper procedure was followed.





Fairway Auto Repair





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