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
I feel like newer transmissions are sealed and don’t need the fluid changed or anything unless problems start happening.
I think I read that somewhere…
I did our 2012 Sienna trans fluid and filter. It has an insane way of accessing the fluid and checking the level. I think the 05 has a dipstick so should be MUCH easier.
It’s not that replacing it, in and of itself, is bad. It’s the way that they sometimes replace it that causes the problem. A full flush is usually the culprit, it can dislodge gunk that might be sitting in a very old transmission with a lot of miles. If the fluid has never been replaced and the transmission has already seen a lot of wear and tear, that gunk might mess with some of the hydraulics of the transmission if it starts getting into places that it wasn’t in before.
There is a component at the bottom of the transmission called the “valve body,” which can be thought of as the “brain” of the transmission. It’s a hydraulic set of tubes, springs, solenoids, and valves, and is responsible for controlling the different clutch packs (the things that grip against the gears and engage them) with fluid pressure.
As you can probably imagine, it takes a lot of fluid pressure to make this work, and it has to be very finely tuned. If something starts leaking, or something starts to get clogged, or a spring, a valve, or a solenoid starts sticking, that transmission is going to start to act wonky.
It’s really only on very old vehicles that you have to worry about this. Something has to go terribly wrong for a fluid replacement to cause a transmission to fail, in most cases the transmission was already on its way out. A lot of people recommend doing a drain-and-refill rather than a full flush on older vehicles, as it’s less risky in terms of potentially dislodging anything that might be in the transmission.
This video is a great summary of Toyota specific transmission maintenance. Very easy and simple to digest. Highly recommend the rest of his channel if you’re interested.
My mechanic said it depends on the transmission. Any regular car you should change the transmission filter forsure. If you drive a high end car, no need to change the fluid.
It’s incorrect to say that you shouldn’t change it. The biggest concern is that changing it can stir up contaminants that then cause malfunctions as well as modify the fluid properties that can expose existing damage.
The correct thing to do is change it, but be prepared to conduct further repairs if you run into problems, including replacing it.
You can choose not to change it, which may prevent the sudden onset of related issues, but you *will* be condemning it to premature failure. Either way, be prepared to replace it. One option just has a chance of postponing the need to.
16,000 km is not an excessive interval for a modern transmission.
Suggestion I’ve heard from my tranny guy is to do a pan drain and refill every 30-40k or less and do the filters every 100k if it has one.
They also recommended that if you have a 150k+ vehicle that’s never had a tranny service/unknown history to replace it in 1/4 or 1/3 of the pan amount over several thousand miles.
You must be missing a 0 because you never have to change your transmission fluid after only 10,000 miles.
There’s a transmission flush and a transmission fluid change. The latter happens with a filter replacement as well just like an oil change. I’m going to compare this to prepping your body for a colonoscopy.
Think of a transmission flush like taking a bunch of laxatives and getting all the poop out of your intestines. It bad because it’s forceful and it will remove bacteria that is good and helps your digestive system.
A transmission fluid change is like going on a fast. You let all the poop come out naturally and then eventually you refill it with more food/transmission fluid when you’re done. The bacteria will still be there but you got the poop out so you could do your service.
Yeah some point as in after 160,000 mi of never being changed, not some point as in 10,000mi down the road. I think routine maintenance is changing it every 30 or 60000 mi, vehicle depending.
Something about how the transmission wears, then mixes with the fluid, and how if you replaced the fluid you’d lose whatever minor miracle was holding your transmission together
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