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To Change or Not To Change? That is the question

Dear, Car Talk Fans,

I need your help. I am the owner of a 2004 Toyota, Corolla S. It has 89,000. On a recent diagnostic check, I was informed that my transmission fluid is not only black (it should be a pinkish/red?) but that it is so old that it has developed particles that have gotten stuck in between the gears of my transmission. As a result, it was recommended that I not perform a transmission fluid flush, nor that I replace the transmission fluid (as it would run the risk of ruining my transmission). Instead, I was told that the best thing to do would be to replace half of the transmission fluid with new fluid and see how that would work. I went to get a second opinion and this mechanic told me that the best thing to do is not replace it since my car has gotten used to it and there aren’t any problems. What this mechanic suggested is that I periodically top off the transmission fluid and hope for the best. I am now confused and scared that my transmission might fail on me. Any advise? Thanks in advance!

I’m sure the Toyota maintenance schedule recommends an automatic transmission fluid change before 89K miles, but that’s a moot point now.

Black is not good for transmission fluid. Black is bad, very bad.

Did you see this yourself, or are you taking someone else’s word for the color? If you haven’t seen it yourself, I suggest you open the hood, remove the transmission dipstick, and look at the color of the fluid. The owner’s manual will tell you where the transmission dipstick is.

What color is it, really?

I don’t agree with the theory that new, clean transmission fluid will ruin a transmission. New, clean fluid is always better than old, dirty fluid. If the transmission has been damaged by the old, dirty fluid the damage is done. New, clean fluid can’t possibly make things worse.

A normal transmission fluid change (not a flush) replaces about half of the transmission fluid. This is probably what the Toyota maintenance schedule recommends.

A transmission fluid flush replaces all, or nearly all, of the transmission fluid.

If I were in your position I’d go with the normal transmission fluid replacement (about half) and then I’d do it again a month later. If there’s a transmission fluid filter it should be replaced each time the fluid is replaced.

Replace the fluid and cross your fingers, lastly don’t blame the mechanic for the outcome. Do flush anything, they are really just wallet flushes.

I believe that Andrew meant to say Do NOT flush anything.

Anyway, what you are experiencing is likely the result of no prior maintenance on the transmission. Failure to do anything now will ensure that the transmission craps out very soon.

If you do a fluid change, it is possible that you may be able to get some more life out of this transmission, but it is far from a sure thing.

So–it is your choice:

Do nothing and a rebuilt trans will be necessary very soon.
Change the fluid and this Hail Mary Pass just might work–at least in the short-term while you save your money for a rebuilt trans.

Yep. Sound advice.

If the fluid is really BLACK, your transmission is about to fail…

A lot of BS posted here…I would certainly invest in a pan-drop fluid and filter change. This can not hurt anything. If it lasts another 10K miles, do it again then. Just for fun, look at the fluid yourself. Pull out the dipstick and look at it! Is it really black??? Make sure you are looking at the tranny dip-stick, not the engine oil dip-stick. They are well marked. Post back with your observations…

No matter what is said, the outcome is usually different. Whatever else is said, the fluid change is due, if only because of the color. To get stuck between the gears and matter, the filter screen would have to be broken and really big stuff would have passed through and your transmission would be gone now, not tomorrow.

Gloom and doom is for stock markets and the doom has a 20% kill rate. The other 80% get richer.

Don’t let them sell you any treatment of any kind that is supposed to make the transmission fluid better or the problem will be guarenteed.

Before doing anything, I would first drop the pan and see whats in there. Black fluid means the transmission has or is overheating. Change the filter and refill. This should be regular maintenance done at 25-30k mile intervals. Get it to a trans shop for evaluation.


Caddyman is right. That old story about not changing the fluid is dead wrong. It has come about since so often transmission fail after a fluid change or flush. Of course no one wants to admit that the only reason they got that fluid change or flush is because they were already having some sort of problem with the system. Those failures are not due to the change, but rather the change was due to the lack of a change soon enough to prevent the damage.

I have 1998 Toyota Camry with 135K miles and to my knowledge was never changed. A mechanic friend told me of stories about burned and poorly maintained transmission risk. His transmission shop told him to not change. A neighbor transmission mechanic for dealer told me that if it were a Ford or Chevy, he would not change but Toyota is OK. I had my mechanic friend drop pan and change filter and pump TF until is was clear. He said that on pan were two magnets which would attract filing as AT wears. He said both magnets were clean and clear. I not yet had any issues with failure.