Tranny fluid change

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Mazda 3 06 Hatchback
I own a mazda 3 06 hatchback sport 2.3l. I bought this car about a year ago with 145k, currently at 152k, did a oil change soon after, and have been curious on the whole tranny fluid change thing. The thing I'm referring to is not replacing it itself but if the previous owner never changed the fluid would it hurt me to change it now. It's still reddish which I understand to be good. (my knowledge includes yt videos, my slightly mechanical friend, and alot of forum reading). I've heard that the old deposits may break free and can cause cloggings and issues. Now let's say you guys(generalizing not being sexist, haha) say I shouldn't because of deposits. Don't take this next part to seriously if it sounds really dumb, I'm just trying to figure out what's possible and what's not. What if I, or had someone else, probably not me, but myb a family member could help, removed the transmissions or wherever the fluid is kept, and kind of cleaned it out after removing the old fluid and before putting in the new, so if there is deposits they wouldn't clog anything, or is it better to flush is, replace filters and check for clogs in places, if that's even how it works, and leave it on the whole time. Again my knowledge is limited, so might just be random talk.
 
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2007 Mazda Mazda3 S
For what it's worth, my girlfriend bought a 2007 Mazda3 S with an automatic transmission last year. It had 120,000 miles on it. I went through and did a lot of maintenance given all the fluids other than motor oil looked neglected. I not only drained the Automatic Transmission Fluid but dropped the transmission pan, changed out the filter and gasket, cleaned the magnet, and filled it with synthetic ATF. There is a method of draining the torque converter via a hose to get more of a complete "flush" too. It shifts significantly smoother now. While flushing a neglected transmission may put you in risk (probably statistically small) of a clog, the logic of neglecting it further is flawed to me. You didn't buy the used car just to have it for a short duration until powertrain failure from neglect, did you? I think taking care of it properly is better insurance for longevity.

Also, if the ATF is neglected, it's very likely that the power steering fluid, brake fluid, and coolant are all likely past their change interval too. They all certainly were for the Mazda3 I'm working on.
 
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2014 Mazda3 S GT auto, 2008 MX5 6-speed
I agree with both replies. Leaving the old fluid alone is the worst option, in my opinion.
 

GJ-Molestor

Banned
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2011 BMW 528i, 2015 Mazda 6, 1995 Nissan Maxima Manual
you arent going to damage your transmission by changing fluid unless you are at very, very high mileage. that is more of a myth then anything else. you will always do more good then bad by changing transmission fluid.

be very sure that you change the transmission filter as well. otherwise, may as well not even waste your time...
 
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2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
Drain and refill. No flushing the tranny if the fluid has not been changed for a long time.
 

GJ-Molestor

Banned
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2011 BMW 528i, 2015 Mazda 6, 1995 Nissan Maxima Manual
Drain and refill. No flushing the tranny if the fluid has not been changed for a long time.
no! this is simply not true!!!

you know what people have done a full transmission service with over 150k miles on their transmission and never ran into an issue right! that is 100% a myth.
 
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Mazda 3 06 Hatchback
Thanks for the opinions, I will have my mechanic take a closer look and see what he says, I'll probably end up flushing it out.
 

DarkRyder

Contributor
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11' Mazda 3i Touring
how is a complete flush performed? I plan on changing the fluid and filter in my mazda 3 soon. How many quarts of what type of fluid is needed? I read somewhere that Mazda uses a proprietary fluid that a lot of the universals arent compatible with.
 
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Mazda 3
On My 2005 3 I changed the fluid around 120000 miles, and there was no red left at all; probably had never been changed. I did 4 changes of the 3 quarts that came out each time, driving it for a few mins inbetween (after refilling of course). It seemed to shift slightly smoother afterwards, although there is still a jump between 1st and 2nd. From what I understand, the transmission pan where the filter is in is glued in with sometype of hard to remove sealer that has to be carefully removed so you don't scratch the sealed area. The transmission drain plug and pan is the one closest to the driver side front tire. It DOES NOT take the Mercon fluid, which is abbrieviayef as m-v. According to mazda, it needs the dealer stuff which is m5 the m here standing for Mazda. I'm pretty sure there is a generic brand of this same type too, but I can't remember the name
 
I did a full flush today at Pennzoil service station (similar to Jiffy or Mr. Lube or whatever other quick oil change places). They did a pretty good job. They have a special device that they connect to the bottom of the engine with 2 hoses. One pumps the old fluid out and another pumps it back in. It automatically measures how much your car needs based on the model. We measured it with the dipstick after and it was perfectly on the notch. The cost was CAD$140

The shifting definitely improved. So much smoother now.
 

DarkRyder

Contributor
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11' Mazda 3i Touring
Do i need to get Mazda trans fluid or is mercon 5 accepted? i read somewhere that the mazda type is preferred for mazda cars?
 
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2006 Mazda 3 2.3L Auto
Automatic transmission are considered mystery boxes. I'm getting ready to rebuild the transmission in my vehicle. A friend of mine warned me not to do so, stating: "You'll let all the magic out that the elves put into it in the factory." For some reason, there are mechanics out there scared to death to touch them and repeat the myth that "if the fluid has never been touched, DON'T." The problem is fluid degrades over time and also picks up contaminants. The filter will only be able to pick up so much particulate until it has reached a saturation point.

One of the reasons I'm rebuilding the transmission in my car is because it has over 144K miles and has thrown a code that one of the shift solenoids is stuck open. When driving, the vehicle will not move once it hits third gear. I have managed to snag a video from a YouTube channel where a transmission rebuilder details how to R&R the FNR5 transmission (Ford's cousin for the Mazda FS5A-EL).

As others have said, drain the pan, drop the pan and clean it and also change the filter. After that, set an interval of ~30K-40K for replacing the fluid and filter.

Here's an example how an average person can perform a transmission flush. With a high mileage, neglected vehicle, I would highly recommend doing this first. After that, follow the above service interval.


Please come back to the thread to share what you learned regarding your vehicle.
 
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Mazda 3
I commute 70 mile ea way to work for past 4.5 years, bought a 2014 touring 2.0 new, now with 176K miles. Had the dealer do complete trans maintenance at 135K. Did radiator flush and fill at 160k. Oil change every 7.5K. Plan to do spark plug change around 185K. Serpentine belt looks like new, completely inspected. Have never had a warning light come on for anything, or anything in the car fail at this point, and it runs great. Dealer says I should get 300K out of it, we will see as plan to buy a grand touring 2.5T next spring as I am sold on Mazda.
 
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2016 Mazda, CX-5 GT
I just changed the tranny fluid on our 2016 CX-5 2.5L over the weekend. it has 113,000 miles. Last drain and fill was at 75K. This time I pulled the pan and changed the tranny filter too. I also let it drain a day and a half. Two things surprised me. First in 38K miles how dirty the fluid looked. Second, I drained almost 6 quarts of fluid. It was on ramps and drained for extended time so maybe they helped. My two previous drain and fills were only about 3-1/2 quarts each.

Now the transmission is quiet and smooth shifting. Almost like new. Was well worth the effort. I do have to say they we have not had to put a dime in this car except for normal maintenance items. I trust it so much that last week we also bought a 2019 Mazda 3 hatchback. Mazda is a very underrated car company.
 
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