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Replace transmission fluid in 2009 Hyundai Accent or no?

In recent oil change, mechanic said to change tranny fluid as it getting dirty but that it wasn’t urgent to replace, can still keep going for a bit.

I had wanted to get it changed that same day, but no time from mechanics at shop so I would have to go back another day and haven’t gone back yet.

For whatever reason, I was researching online and found mentions of times where it may be better not to replace tranny fluid even though old as it has worn down well with the transmission & swapping it with new fluid makes it a different environment and could cause problems instead. And it applied to new and/or old cars, I forget exactly.

So for this particular car, should I change the fluid or not? It’s at close to 30,000 miles. When I checked it, it didn’t look pitch black dirty, but then again I’m not a mechanic to know exact dirty level coloring.

I don’t think car’s had tranny fluid changed since bought from dealer, so it’s been a few years now.

The fluid really needs to be changed every 30k miles and the bit about new fluid causing problems is an old wives tale.
One thing you don’t want to see is dirty fluid as that’s a sign of overheated fluid and friction material from the clutch packs; meaning the transmission days are numbered.

Look in your owners manual for the maintenance schedule, it will tell you when the transmission fluid needs to be changed. Typically though, many cars do not list changing the ATF as part of the regular service unless the car is subject to “severe service”. Some do not list it even then.

Some transmissions use a new type of ATF that is supposed to last the life of the vehicle, we have heard this before, but who knows, maybe this time they got it.

Generally speaking, most of us believe that a simple drain and refill every 30k miles will insure the transmission will last the life of your car, or darn near it. If your transmission has an accessible filter, it should be changed either at each ATF change or at least every other one.

If you have a CVT transmission, it takes a different ATF. In any case, who ever you select to change your ATF, the MUST use the SPECIFIED ATF. Do not allow them to use a generic ATF and put in additives as many shops and particularly quick oil change places like to do. You also do not need to have it flushed, a simple drain and refill is all you need. A flush or “complete fluid exchange” is for people who have not properly maintained their transmission or have put in the wrong fluid, or had a quicky oil change place do it.

Todays transmissions are electronically controlled. Which means there are solenoids/switches that are exposed to the transmission fluid. If the transmission fluid breaks down to a point where gum and varnish begins to form, this can cause these solenoids/switches to stick, and the transmission doesn’t shift properly. Which then leads to more transmission damage.

Replace the transmission fluid and you prevent that gum and varnish from forming causing those problems.


Let me add this, what you saw online can be one of two cases.

One is a car where the owner as done zero maintenance on the transmission. After 100-150k or so, sometimes less, the transmission begins to shift badly, slips or gives other problems. Now the owner decides to do a fluid change and a week or two later, the transmission completely fails. The owner blames it on the ATF change, but the real problem was the owner not following the maintenance schedule. Thats like never doing your first oil change after the engine is smoking.

The second is when the mechanic uses the wrong ATF or uses a generic ATF with some additives that are “supposed” to make the generic ATF meet the factory specs.

The right thing to do is what you are planning and that is to have a drain and refill every 30k. A drain and refill will only replace about half your ATF, but by doing it on schedule, that is enough to refresh the additives in the ATF so that your transmission is protected.

Some places will try to convince you that you need to have the fluid flushed so that 100% is replaced. If they use a flush machine, one that forces the ATF through the transmission, it can damage some transmission. A fluid exchange machine will use the transmissions pump to circulate the ATF and that is not likely to damage anything as long as the transmission is first drained and the filter (if applicable) is cleaned or replaced. But a fluid exchange is not necessary as long as you follow the schedule and use only the specified ATF.

Those places that flush the transmission will in all likelihood NOT replace the filter

They will claim it’s not necessary

You don’t change the oil, but leave the old filter in place, right?


Some transmissions don’t have a servicable filter.



You are correct in that some transmission really don’t have a servicable filter

But if the transmission has a pan . . .

Speaking of filters, Toyota and some others insist that their transmissions don’t have a filter. They insist that thing that stares you in the face when you remove the pan is actually a screen, which is supposed to be washed.

Yet all of the parts stores have it in stock and call it a filter

My wifes 87 and 96 Accord didn’t have a serviceable filter. You just replaced the tranny fluid every 30k miles.

Toyota is now using the WS tranny fluid that’s suppose to last a lifetime. Which you really should NEVER EVER DO.


Those Hondas that you mentioned had an interesting transmission

It was basically a manual transmission, which doesn’t have a filter

Perhaps someone else can explain it better than I did

Those Hondas that you mentioned had an interesting transmission

It was basically a manual transmission, which doesn’t have a filter

These were automatic transmissions.

@db4690, the Japanese auto transmissions I’ve seen (back to 1973) use parallel shafts that resemble manual transmissions, whereas earlier American transmissions often used planetary gears.


“These were automatic transmission.”

Yes and no

The driver didn’t shift . . . so in that sense they were automatic transmissions

But if you ever saw one apart, or even saw the exploded view in a book, you’ll know that they are about 80% manual transmissions and 20% automatic transmissions

But if you ever saw one apart, or even saw the exploded view in a book, you'll know that they are about 80% manual transmissions and 20% automatic transmissions

I’ve only torn into ONE automatic…built a couple manuals…MANY MANY years ago.

Hondas do have a filter its not servicable


Please explain what Honda transmissions you are referring to

CVT . . . ?

Or those “automatic” transmissions which are more closely related to manual transmissions . . . ?

Drain or pan drop and filter every 30K is the general consensus, not a flush. Use factory OEM fluid. That’s about all you need to know. I believe some fluids now become dark quickly and is not an indication that it is dirty or worn out but I could be mistaken.

The Honda transaxles are a shaft/ intermediate/ counter shaft arrangement. Instead of syncronizers and clutch sleeves to engage gears to the shafts, there are clutch packs that connect the free wheeling gear to the required shaft at the appropriate time. The amazing thing about these transmissions is that one gear’s clutch has to release while another is engaging. All this has to be timed without allowing engine flare or significant transmission bind, i.e. two clutches engaged at the same time.

To change the ATF strainer the rear cover has to be removed to gain access to the valve body so it would probably require an R & I of the transaxle.


You did an excellent job explaining why the Honda “automatic” transmissions have much more in common with an old school stick shift transmission

I already knew the inner workings, but I wasn’t able to explain it like you did