why should you not change your transmission fluid if you’ve never changed it last 10,000 miles.

Question

For context: I have an older Toyota 05. 160k miles. Transmission fluid looks kinda brown and mechanic said I should do a flush and quoted me 300$. I’ve also heard that at some point you shouldn’t change the transmission fluid if it has t been changed in awhile. Why is this?

In: Engineering

Answer 1

Drain, filter change, and refill is fine and what is usually recommended in the manual. The “flush” a lot of shops will push is not necessary.