Just food for thought here----------I am a "newer" member and thought I'd pass this on. In March I bought a 2010 Fit Sport with 115K miles and promptly changed the automatic transmission fluid. Was not sure of the past history and even though the transmission was shifting "okay" I wanted to be proactive because I'm going to keep this car for a decade. Anyway, not long after changing the fluid I planned on changing it again in a couple of weeks or so, plus install a new filter. Did that yesterday and was surprised on how dirty the fluid still is! I know that when changing by draining, only about 2.7 quarts of fluid is changed in the entire transmission, leaving the rest of the "dirty" fluid there. That's why I wanted to change the fluid again, to get it cleaner. In retrospect, because of the dark color of the fluid, the two past owners of my Fit may not have ever changed this fluid!
When asking my local Honda dealer about this process, I asked about how many times I should change the fluid, to eventually get it to an acceptable, clean level. He indicated that only once should be good enough. But, again, by looking at the dirty fluid yesterday, it was like I never drained it the first time. And the Honda dealer said that they do not "flush" the transmission but only drain it with the 2.7 quarts. I also asked him how many times I should do that process to get the fluid to an acceptable cleanliness and he said that after the first change, good enough! Well, again, by looking at the color of my fluid that I drained yesterday, once isn't enough. Long story short, even though it's going to take a couple more changes of fluid to get it to what I would think is an acceptable level of clean fluid, I'm going to do this process a couple more times in the next few weeks. I can't believe that draining the transmission and keeping really clean fluid is not done more often on these cars because it is every bit as easy as changing your oil! Oh, and no "slippage" yet and hopefully that won't be an issue.

 

You will not get a really good answer by asking the guy behind the counter at Honda. The fact that they only drain the fluid during an oil change really shows they do not really care.

The only way to really drain the fluid is to use a transmission fluid machine. You unplug the oil cooler and collect the dirty oil. The machine then adds new oil into the cooler. The flush is complete when clear fluid comes out of the transmission.

By draining the fluid when the car is off you get less than 50% of the old fluid out. If you do a second change, you'll get around 75% of new fluid, a 3rd will get you to 87% or so. It can get expensive and messy to do that change by yourself.

 

Thanks, carotman. What is the process of using the transmission fluid machine and do I rent this? Any threads on this site for the process? And by-the-way, with changing the fluid like I am doing, if I change the 2.7 quarts, four times to get a final, clean fluid, that whole process would still cost me less than the $125 my local Honda dealer was going to charge me for ONE 2.7 drain and fill! Ahhhhhhhhhh! And again, it's easier than changing the engine oil because I don't have to mess with the filter again.

 

I would just do the change a couple of times, spread out over several weeks of driving. By draining and replacing the fluid you are getting the benefit of the fresh fluid and additive package. I wouldn't worry so much about how the oil looks, only a lab oil analysis could tell you the serviceable condition of the fluid. I maintained my Honda Ridgeline by doing this over 150k miles, with a significant amount of towing, and had no issues. I would just drain and replace the fluid, drive for a week, then repeat, and was good for that service interval (I did it about every 30k, due to the towing/severe service). Never did a machine flush, and never had a problem.

 

I think you are right with doing the change over a few weeks. I've read where some do the four time change right away, and not adding many road miles but I'm not sure that the full, "cleaning process" over minimal driving, is complete. I've read that transmission fluid is highly cleansing so by driving a few miles at least, then changing, helps in that process. But I will do the four time change. In a week or two, it'll be time for the 3rd change and in another week or two, the final, fourth change. You see, I'm anal when it comes to stuff like this and I will post the results after the final changes if those changes result in a marked change in better shifting. Especially doing the four time change because it's so easy! I will post results at that time. Thanks for that info!

 

After the first fluid change, you are looking at 50% new (vs old) fluid. Assuming an even distribution after allowing the transmission to shift through all the gears, your next ATF drain/fill would be 75%. The next would be 88%, then 94%, etc. (Oops, missed carotman's post where he already posted the numbers...sorry for the repetition)

FWIW, I did one drain/fill at my last oil change. My next one is coming up, and I plan on doing the ATF drain/fill as you had mentioned. A case of Honda ATF is cheaper than one service at the dealer, and I feel accomplished afterwards.

 

Yes, I agree. I know not much about all of this so doing this, which I feel is pretty important, does make me feel like I'm not completely dependant upon the dealer.

 

What are the symptoms of having slightly low transmission fluid?

 

Hi fujisawa. I don't really know what the actual symptoms would be so maybe someone on this site can tell you. Good luck. :-)

 

Don't drive yourself nuts with this. Honda well knows how much is left after a drain and fill, etc.

 

All done with the four fluid changes. I experienced no difference in performance until the 3rd change. I had been experiencing a "sluggish" shift around 10 m.p.h. and by the 3rd change, I noticed a quicker shift, around the 10 m.p.h. point. Otherwise, nothing else noticed and no more improvement with the fourth and last fluid change. But at least I know the transmission fluid is pretty clean and I won't change it again for another 30K miles.
Again, I did change the tranny filter too and I bought a new, magnetic drain plug. When comparing the strength of the old magnetic drain plug with the new----the new magnetic plug was much, much stronger than the old! Over twice as strong when comparing the two. I'd recommend a new one to anyone who has similar miles on their Fit.
Hoping my transmission wasn't harmed by the past two owners, through neglect! Oh, and it's unbelievable how much a difference there is when checking the fluid level on completely flat ground versus just a very slight incline! Make sure you check your level on very flat ground!

 

Update: Now that I've been running the car for a few weeks with that last fluid change, slowly but surely, the shifting at that noticeable 10 m.p.h. shift has improved quite a bit! I think that because the fluid was much cleaner, the actual cleaning process is slow but sure. Before any of these changes, that shift point could take close to two seconds to shift into a higher gear! Now, it's pretty quick and responsive, enough to where I'm not sure it's not normal. I'm going to let this fluid clean in the system for a couple more weeks at least, then do one, final change, then wait for another 30K before another change. This process was slow but I think and hope it was worth it by extending the life of my transmission.