from Goss’ Garage by Pat Goss

Modern automatic transmissions had very humble beginnings back in 1904 with a clunky centrifugal unit from the Sturtevant brothers of Boston. Over the years automatic transmissions have evolved into reliable, economical and fun to drive units that work through a series of sensors and an onboard computer to mastermind their decisions. Pretty amazing and well beyond anything even imagined by most of us a few years ago. But although sophistication brings reliability it really requires your help. Help or face repair bills that were also unknown a few years ago. In 1970 the average price of a new car was $3900 today the price of a transmission can easily exceed that!

So with replacement cost so high and prevention so cheap transmission maintenance makes a lot of sense. Now is the time of year to protect your transmission; before those scorching-hot summer trips. Service used to be nothing more than dropping the transmission pan, replacing the filter and refilling it with fluid. But that was a long time ago; proper service has changed because that old-school service can actually decrease rather than increase transmission life. The old method didn’t clean the transmission and it only replaced about one third of the fluid.

That good ole process left the transmission as dirty as it was before the service and still filled with two thirds old, worn out fluid. Without a thorough cleaning the new more-detergent fluid softens dirt allowing it to circulate through the transmission under high pressure leading to wear. Yeah I know you’re thinking your filter will trap the dirt but it won’t because the particles are so small they pass right through a transmission filter plus many transmissions don’t have filters, they use screens instead.

Today a proper transmission service is flushing, which dramatically extends transmission life. Flushes are nothing like those old fashioned fluid services. Flushes begin by circulating special cleaning chemicals through the transmission to remove the yuck that has built up in the transmission as the fluid deteriorated from heat.

During this process the car is connected to a transmission flush machine and every drop of fluid that circulates back into the transmission first passes through a bank of highly efficient fluid filters. The filters trap all the bad stuff to keep it from reentering the transmission and causing wear. Once the cleaning is complete the machine installs new transmission fluid. Plus flushes replace every drop of fluid not just a small portion.

Ideally a flush should be done every two years or 24,000 miles because clean fluid in a clean transmission means longer life. Also contrary to what your dealer may tell you there is no such thing as transmission fluid that lasts forever. Nothing lasts forever, all fluids wear out and when the fluid wears out the transmission soon follows. Sealed transmissions don’t exist either, they can all be serviced.

Finally beware of shops that sell you a fluid exchange and call it a flush. A fluid exchange is quick and highly profitable for the shop but a waste of your money. Fluid exchanges can be done right in the service lane in about half an hour where a flush requires about an hour and a half.

I know the economy is tight but avoiding preventive maintenance is truly a false savings. Unfortunately metal doesn’t understand economics, can’t sympathize with your tight money and if not kept properly lubricated fails. Repair always costs a lot more than prevention. For what it’s worth I’m a firm believer in the BG Products flush system and chemicals so by selecting a BG Products shop ( you’re sure to get good value. I’ve tested and compared a lot of products and flush systems over the years and BG has always come out on top.