I was told it was not necessary and advised to do this for the TLX's 9 speed. I personally feel it helps prolong the life of the transmission by doing the 3X drain and fill. Anybody know anything about this ?

 

I have asked a professional auto mechanic and a buddy of mine who is a high school auto teacher. Both think this practice is a waste of perfectly good fluid and won't extend the life of a transmission any more than it will already last.

 

In my TL's owners manual it says to drain and fill 4X to thoroughly exchange and remove all the old fluid in the transmission. Replacing it once does not do that.

 

Of course once doesn’t flush all old fluid. I’m sure dealers follow the manual to the tee. It’s your car and you can do whatever you’re gonna do. I’ve asked two professionals about this (actually regarding my other Honda). They said it’s unnecessary. If you want to pay for three or four rounds of clean new fluid in and right out the drain, go for it. If you have an honest mechanic, be prepared for them to recommend just replacing the fluid.

 

I would space them out per oil change rather than do it all in one fell swoop.

 

The first notification to change the fluid came on at about 60,000 miles. I personally think that is too long but that's what the maintenance minder timing was set to. I just drained it once at that time. After that it came on at approximately every 40K miles. I did the drain and fill 4x since the first change. My transmission needed to be replaced at 175,000 miles. I vowed to do everything I can to prolong the life of the new one. Of course driving habits and environmental conditions have a lot to do with how long it will last. But how can a mechanic say it's not necessary when common sense tells you that all new fluid is better for the parts and health of the transmission.

 

I don't know. You could ask a professional rather than a bunch of owners and aficionados on a forum. All new fluid is indeed better - everyone and their mom would agree - but I think there are practical limits to a perfect flush. You will never get everything out. If you analyzed what came out of the drain, you would see the first round of old stuff looks dirty and used. Add new fluid and drain again, maybe expect 5-10% of what came out to be the old fluid. I don't know that - I'm just guessing. So at 1x you get 90% optimization. At 2x, maybe gain another 2%, so you're 92% clean. At 3x, you're 93% clean. At 4x, you're 94% clean. I'm just making this up. There will always be some PPM remnant of old mixed with new. When I asked for a 3x D&F, my mechanic said he can but prefers not to waste good fluid unnecessarily. I interpreted that to mean any more than 1x D&F at 90% new fluid means so little gain up to 94% clean for the amount of money and the environmental ramifications of disposing of so much essentially uncontaminated fluid.

My first A13 just came on at 50k miles. I haven't decided whether or not to change the fluid since my tranny was replaced about 10k ago. I might just to flush out any metal particles and see if new fluid helps the ZF9 performance at all. I think I speak for many when I say I would absolutely love to get 175,000 miles out of a transmission. That is pretty darn good. I don't know how much more life you expect out of a major component. What failed at that mileage that required replacement? Does the torque converter wear down? Does if start laboring to shift into certain gears?

 

I've heard a few mechanics who agree with this but I'm struggling to see the logic - from a physics or science perspective. I mean, ultimately old fluid is going to be dirtier, resulting in more wear as well as have reduced lubricity and break down of additives due to shearing. So unless there's some other factor that's the main culprit of transmission failure, making wear a non-issue, the value in newer fluid seems to be a no brainer.

Either way, with fluid being relatively cheap vs. a new transmission (especially if you buy DW-1 in bulk online or use Valvoline Maxlife), I think it's near foolish to not change your fluid simply because it's a "waste of perfectly good fluid". Even from the environmental standpoint, ATF is recycled right along with motor oil so other than recycling processes, it's not as if you're doing some sort of damage to the environment. As long as you're not doing something stupid like pouring it down a storm drain or throwing it in the garbage. That's a little FYI by the way. You can mix it right along with motor oil and bring it to any discount auto parts store. I've specifically asked both Oreilly's and Autozone. Oil recycling is good for any oil based product. Manual or automatic trans fluid, motor oil, differential fluids, etc. Not antifreeze or brake fluid though.

 

Just to be clear here, I completely agree. I'm not avoiding trans fluid replacement to avoid disposal of used trans fluid. I'm only considering not changing trans fluid per my maintenance minder because my maintenance minder doesn't know my trans/trans fluid are only 10k old.

The point about wasting fluid is that each drain & refill a) costs money and b) creates more waste to recycle. I saw this over on TLXforums:
https://www.tlxforums.com/threads/tr...66/post-303410

So if the ZF9 takes AT3.1 fluid at $36.16/quart and each D&F is 3.5 quarts = $108.48 and 10.5 quarts to recycle. Someone else said it's as expensive as $55/quart. No wonder dealers are charging over $500 for this service.
As opposed to DW-1 which runs $25 for 3x D&F, but you still have 10.5 quarts to dispose.

The point about recycling is simply that a D&F creates more waste then is arguably necessary. If they 3x D&F every car that came in, mechanics would have 3x as many oil pickups, 3x the cost to dispose and the recycling center would have 3x as much oil to process. That involves energy at the very least and it's simply 3x more than we need to do. Anyone is free to do this. Lord knows everyone consumes more food, gas and goods than they need every single day.

 

Ah, I wasn't aware of the different (more expensive) fluid. That may change things.....

 

Holy cow. How many miles do you have on your TLX?

 

I do agree it is very wasteful and costly to do the repetitive drain and fill, and I am a very environmentally conscious and caring person. But I was told that Honda firmly does not recommend using a fluid exchange machine. That removes any options. My owners manual actually says to D&F 4x to thoroughly change the trans fluid. No you never remove 100% of the old fluid, but a lot more than just doing it once. If it lengthens the life of a costly transmission (which I believe it does) isn't it worth it ?

 

It all depends on how often you change fluid. My personal experience is about 30k from brand new. The longer you wait, the dirtier the fluid. You should never wait so long that it takes 3x.