Can changing transmission fluid loosen the bands inside?

Dear Car Talk

Dear Car Talk | Aug 01, 1992

Dear Tom and Ray:

I have a 1988 Grand Am with about 87,000 miles. I average about 35,000 to 40,000 miles a year. I have kept up on regularly scheduled maintenance, oil changes every 3,000 miles, etc...except for one item. I have only had the transmission filter and fluid changed twice since I've owned the car. My friends have said that it's bad to change the fluid in the transmission, due to the fact that it would "loosen up" the bands in the transmission. What do you think I should do?

RAY: Chuck, your friends are wacko. They're proponents of the "let sleeping dogs lie" school of thought...which is fine for dogs, but lousy when it comes to transmissions.

TOM: The bands are not stretched or loosened by fluid changes. When you change the transmission fluid and filter, what you're doing is draining out little pieces of the transmission that have been shaved and ground off over time. And if left inside the transmission, these pieces will ultimately cost you a lot more than a fluid and filter change.

RAY: You're doing exactly what you should be doing, Chuck. You've already changed the fluid twice, which puts you about two changes ahead of the average car owner. The average guy has his fluid changed for the first time at about 90,000. And it's usually done by Aamco, at the same time that they're putting in the rebuilt transmission.

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