A to-the-point question: When is too many miles for an automatic transmission fluid/filter change to be considered beneficial? Would it be helpful as long as the transmission is healthy and shifting properly? I'm not interested in trying to revive a dying transmission, but I'm looking to buy a vehicle with over 171,000 miles and I'm going to preemptively assume the seller hasn't changed the ATF.
Thanks.
Check the fluid. Is it burned and gritty? If so the grit in the fluid is material from worn bands and clutches, and may be all that is providing enough friction to permit the transmission to operate.
If the fluid is maybe just a bit dark but otherwise clean, changing it via drain & fill (not flushing) should be no problem. If there is a replaceable filter you would want to change that out as well.
It depends on the nature of the miles and the time frame. Highway miles usually mean far fewer stop-and-go shifts, considerably less wear on the tranny.
Likewise, 171K over 5 years is one thing. The same mileage over 13 years is another matter.
How do those variables fit into your thought process?
I'll have to ask the seller for further information on the nature of the miles, the car is an '04 so it's somewhat older, and I could certainly see alot of wear accumulating in that amount of time.
Refer to the FAQ for in depth information. Shortly, it depends on the ATF's condition and color.
