Automatic Transmission Servicing

Automatic Transmission Servicing

How to avoid some common, and potentially costly, service mistakes. 

The tube is still there, but you’ll need to order your own dipstick if you want to check the level on this trans.

John D. Kelly/Motor Age — I own two vehicles that do not have an automatic transaxle dipstick to check the fluid level. One of these vehicles is a General Motors product; the other is a Toyota product. And they are not the exception. Ford also has automatic transmissions without dipsticks as do Chrysler, Mercedes and other OEMs. The lack of a dipstick is no accident; the transmission manufacturer does not want the customer to have access to the fluid. They call it “lifetime fluid,” and it supposedly never needs changing, but it does need to be checked when there is a sign of leakage, if the transmission is having problems or if the transmission was opened for any reason. Some transmissions are so sensitive to improper fluid levels and fluid types that transmission problems or even damage can occur with the slightest under fill or over fill.

If your shop is in the business of servicing or repairing automatic transmissions or if you are just performing quick services such as an engine oil change or a transmission fluid flush, you better not tell a customer that their fluid level is “OK” unless you really checked it the proper way. I have taught classes on automatic transmission diagnostics, service and overhaul for 22 years. Most technicians I have had in class (experienced or not) make simple mistakes that cause them to check the fluid improperly.

Checking an automatic transmission’s fluid level properly requires four resources; access to the proper service information, up-to-date training, adequate time to perform the fluid level check and access to special tooling if required.

Adventures In Reality

My first vehicle without an automatic transaxle dipstick, a Toyota Highlander Hybrid, was purchased new in 2008. I received free oil changes every 5,000 miles for the first 75,000 miles as part of the purchase, so I had this vehicle serviced at the dealership for the last five years (83000 miles). The green-yellow-red colored multi-inspection check sheets I receive with each service always show all of the fluid levels as being OK. The problem is the fluid level check plugs appear to have never been removed, as evidenced by the factory paint marks on them.

Source: Motor Age

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.