Transmission fluid changes in older cars with high mileage

I was wondering what everybody's opinion is, based on experience or expertise, regarding changing the transmission fluid in an older high mileage car.

I know there is a school of thought out there that transmission fluid should never be changed or changed very infrequently.

I'm wanting to sell my 2004 Volvo with a little over 200,000 miles on it and one of the things is that perhaps the transmission fluid should be changed. The fluid is a little dark. There is nothing wrong with the way it drives and the tranny is smooth. My fear is that I change the fluid and it falls apart.

Thanks in advance for any thoughts or advice.

 

There is another school of thought too - if you are going to change transmission fluid start doing it slowly early and avoid doing full system flushes. If you haven't changed it by say 100k miles it is probably best to leave well enough alone at that point.

I've seen people complain on Yelp and other review sites that some Firestone shops will actually refuse to do a fluid replacement or flush on a high mileage transmission since they don't want to be blamed if it breaks after the service.

If it was my vehicle I wouldn't change it at this point. More likely to do harm than good.

For my truck I plan to do drain and fill (but not flush) every 30k miles. That way by 120k miles almost all of the original fluid will be out of the system and the transmission will not have seen any sort of shock from all new fluid. I'm probably being irrationally conservative in my approach.

 

You're approach makes alot of sense and I feel like I've learned quite a bit from your post.

Fluid exchange seems more and more like a bad idea.

I'll have to figure out when my last fluid change was. It's possible it's gone 100,000+ without one.

I think I'll explain to any prospective buyer the risks of changing the fluid and let them make the decision.

The funny thing about this car is that it was, and still is, a great car. The best car I've ever owned before my Tacoma.

If Kelly Blue Book is to be believed it only has a trade in value of $750 and a private sale value of about $1,800. It's worth way more than that to me as a third car...except I don't need a third car.

Where I live, crappy beater cars with paint loss and rust go for about $3,000. I think Kelly Blue Book values represent a "low book value" for which it's a good deal to get one at "book value."

I remember as a kid my dad always thought he was getting a good deal on a nice car at "book value." It was even a bigger deal if it was below book value. But it was understood that used car with no known issues would be a little above book value.

Thanks again for your post because it does help to understand transmissions. It wouldn't surprise me if unchanged transmission fluid starts taking on some sort if chemical equilibrium that could be thrown off if all of it was changed at once.

 

I've heard it not only from Firestone shops but others , around me some shops straight up ask how many miles you have on the vehical and when it was changed last . I've also had them straight up refuse to do it once they found out the situation .

@OP I've also heard this too and am Leary of doing it on another vehical I own with 150k + and the AT fluid has never been changed . The concensus that I've gotten from calling 5 different shops around me is to leave it alone til it blows up . I also have no problems with the vehical I mention , it shifts good , doesn't jump or bang into gear but the fluid is dirty and when certain shops check it out of courtesy they "recommend" I change it .

In my situation with a Mazda 3 with 154k and the trans fluid never changed I'm leaning toward not doing it and just running it til it blows up . I don't really know myself if this is right or I should do it but the impression I get is to not too from the shops that I've called so far