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Black transmission fluid, 45K miles

I’ve had this 2009 Corolla for about 4 months. I took it to my private mechanic for the 45,000 mile service (first service appt since I bought it). Mechanic said the transmission fluid is BLACK and is changing the fluid and filter. I haven’t noticed any problems with the car and neither did the mechanic during his test drive. It seems to me that having black transmission fluid at 45,000 miles would be cause for concern. Is it?

The transmission is still under warranty. If I were to take the car to the dealer is there anything they can do to check the condition of the transmission? On one hand it seems foolish to go to the dealer and say Hey, my car runs great but this fluid was black…can you take apart my tranny to see if it’s ok? Then again, if the transmission goes 5K miles after the warranty expires I’ll be kicking myself.

Yes go to the dealer, for no other reason then to document it. Plus let them do the service, again so you know they right stuff was used and to document that it was done. Shoud you have an issue in the future the documentation will be invaluble…

PS have you checked the fluid your self???
PPS was this car a rental car in its past ownership??

Black transmission fluid usually means the fluid is burnt and full of friction material. That’s bad news.
Did your mechanic tell you if the transmission pan had a lot of sludge in the bottom and/or metallic flakes and so on?

The car could be scanned and transmission pressure tests performed but if the car were mine I would be very nervous about the condition of the transmission and its longevity if the fluid was accurately described to you.

No I didn’t check the fluid myself. Yes this was a rental car. I purchased the car directly from the rental agency.

I already came to the conclussion that from now on the dealer should do all my service. Sigh.

ok4450, it’s actually still at the mechanic now. He’s doing the service as we speak so I don’t have that information…but I will when I pick it up.

With a used car (rental, lease, or otherwise) you never really know what’s happened in the car’s past.
On several occasions while at the drag races I’ve seen people show up with brand new turbocharged Neons and Subarus which still have the dealer paper tags on them. That means they’ve had the cars for less than 30 days and already pounding them into the pavement at the drag strip.

On the Speed Channel TV show “Pass Time” a guy on there was doing drag strip runs on a new Dodge Charger which they freely admitted had been obtained from a car rental agency.

One young guy at the races one evening started whaling on his new car at 5 P.M. when the track was opened. I left somewhat early (about 9 or 10) and that kid was still beating up the asphalt. I couldn’t even start to remember how many passes he made.

Eventually cars that have been driven like that, or similarly on the street, end up for sale to the public.
Stay on top of this thing though.

“I already came to the conclussion that from now on the dealer should do all my service.”

Well, if you like paying more $$ that’s the way to go.
Most routine work can be done just as well at an independent shop for less.
Just insist that fluids that meet Toyota specs are used, not “universal” stuff.

Check with your Toyota dealer service department. IIRC the T-IV fluid is black but don’t know about the WS fluid. You should check your Owner/Operator Manual to determine which fluid your transmission needs. Make sure that whatever is used to fill or flush the transmission matches the specification of the correct fluid. To be safe use fluid bought at the dealer.

Hope this helps.

You should have looked at the transmission dip-stick BEFORE you bought the car…You will get little help or sympathy from the dealer…

I’ll have to echo circuitsmith here. You do not have to go to a dealer.

I already came to the conclussion that from now on the dealer should do all my service. Sigh.

I really don’t see how you came to that conclusion.

I only said that so that if you have an issue with the trans in the future its documented, and the dealer did the service so they cant point fingers… I also wonder if you mechanic is useing black but really means just very dirty, but said black so you would feel pressure to do the service.

Rental cars are in and of themselves not a bad thing, most are driven by buisness guys traveling and famillys on vacation. They low end cars though (economy and compact) are more likley to be beaten up by the renter as they are usually younger with out kids, etc…

I think this is a typical upsell and “black” is a poor way to describe the appearance of the fluid. He should have said dark or dirty. If the fluid is black I don’t think he would offer to service the transmission because of a risk the there may already be internal damage.

If the transmission is still under warranty then dont take it to a mechanic, go to the dealer and let them fix it under warranty.


I think this is a typical upsell and “black” is a poor way to describe the appearance of the fluid. He should have said dark or dirty.

Nevada and gsragtop you appear to be correct. Picked up the car little over an hour ago. I asked the receptionist to get the mechanic so I could talk to him. He had this puzzled look on his face when I asked him “how bad is it?” and if there were any metal shavings or sludge when he did the trans service. He said no…just that my trans fluid was “dark” (he said BLACK when he called me this morning) and that happens when the fluid is near the end of it’s life. He went on to say the he suggests a trans flush every 30K miles so I was over due.

Earlier today I downloaded my car’s maintenance schedule. Now I’m really confused. I went through it three times. Unless you are towing with your vehicle Toyota does not appear to have a suggested mileage for changing the trans fluid. Maybe I missed it but I don’t think so.

Thank you all for your input. I do appreciate your time.

My daughter has a 2003 Corolla and we had the same problem with the transmission fluid. I do all the work myself so this is first hand info. I was going by the book so checking the transmission fluid was not on the schedule. At about 75k miles, she complained about shifting problems, thats when I discovered that it was almost black.


I did a simple drain and refill right away. a couple thousand miles later, I dropped the pan and cleaned it and the filter. The I did a drain and refill every 30k since and at 150k miles, it is working perfectly. Your mechanic is almost right as far as I am concerned. I just don’t like the “flush”. A drain and refill every 30k with a drop the pan and clean the filter every other time is all you need.

But then what is the mechanic going to do with his expensive flush machine?

I think quick change places and some shops have gone to doing flushes because it is quicker, easier and much more profitable than doing a pan drop and filter change. They also don’t have to worry about their ham-fisted employees stripping the bolt holes in the aluminum transmission case.

Someone will have to prove to me that these flush machines will get the fluid out of the torque converter before I buy it.

I have good success with saving transmission cases by epoxying studs (actually cut off bolts) into stripped holes.

Have the fluid drained and replaced. Do not have it flushed. The high pressure from the flush could damage your transmission. Honda states in the owner’s manual not to flush. Toyota may have a similar recommendation in the Corolla manual.