Many vehicle manufacturers today insist that their automatic transmission fluid (ATF) is formulated so that owners never have to change it. The term “lifetime” immediately makes you think that this fluid will last forever and that it’s one of those things to file under “no need to worry about it.” That is not the case at all. Yes, it is true that most modern synthetic fluids are better than their predecessors. However, that does not mean that a vehicle owner can go 200,000+ miles and never replace their transmission fluid and filter. Some say that it is a manufacturer’s marketing gimmick since many car owners do not keep their vehicles past 100k miles. Could it be that their “lifetime” fluid is good for the life of the transmission or the life of their warranty, which could have expired at 100k miles ? We are not here to judge but rather to share our viewpoint on the matter.
If a vehicle’s lifetime transmission fluid is left unchanged for the life of the vehicle, serious damage can occur to multiple vehicle components including filter, oil pan, seals, etc. Metallic deposits can build up on an oil pan and filter and can cause serious transmission damage. Just this week, we have performed three transmission services (VW Beetle, Toyota Corolla and Pontiac Grand Am) and metal shavings were found in all three vehicles. Each of these vehicles also had noticeable discoloration of the transmission fluid. Had this fluid remained in the vehicles indefinitely, the existing issues could have gotten much worse and much more expensive.
At Das Autohaus, we constantly mention preventative maintenance and how very important it is to the life of your vehicle. We recommend a transmission service every 40,000 miles for VW & Audi DSG transmissions and every 60,000 miles for automatic transmissions. Spending a little money in advance will most certainly reduce the out-of-pocket expenditure if you leave an issue or service item unattended. Bottom line: Change your transmission fluid …. It is much less expensive than buying a new transmission !
The attached blog picture shows some of the internal parts of an automatic transmission. Note the electrical wiring and components that sit in an oil bath their entire life.