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Discussion Starter #1
I have a used '02 MDX of unknown maintenance history, and would like to make sure the transmission doesn't die on me.

I've read the thoughtful and well-written:
TransCooler

I brought up some concerns to one of the parts department employees at the local Honda dealership, and he gave me the predictable "just leave it alone and run it until it dies" answer.

When asked about replacing the existing fluid with synthetic, he said that "synthetic has a different viscosity than regular oil" and because of that, "synthetic would cause the seals to leak".

I'm unconvinced.

Also claimed replacing gear sensor/switches might lead to a cascade of changes in the transmission.

"I've been doing this for 15 years, and the biggest mistake I see is people start to replace parts on/in the transmission when the transmission isn't broken."

Of course, he also admitted that there's no way to diagnose if something is in the process of going wrong in the transmission without disassembling it....

Also, if someone could check my facts and figures,
it's my understanding that the '02 MDX has 9 quarts of ATF, 5 of which drain out during a drain-and-fill.
This means that after the first D&F, 4/9 of the old fluid remains (44.44%).
D&F again, and (4/9) * (4/9) leaves about 19.75% old fluid.
the third D&F would result in 8.78% of the old fluid remaining in the system.

But I always see "3x3" fluid changes which suggests that only 3 quarts drain out.
This yields 6/9 old fluid after the first D&F (66.67%)
(6/9) * (6/9) after the second D&F (44.44%)
and after the third D&F, 29.63% old fluid.

Can anyone help me out here?
 

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I have a used '02 MDX of unknown maintenance history, and would like to make sure the transmission doesn't die on me.

I've read the thoughtful and well-written:
TransCooler

I brought up some concerns to one of the parts department employees at the local Honda dealership, and he gave me the predictable "just leave it alone and run it until it dies" answer.

When asked about replacing the existing fluid with synthetic, he said that "synthetic has a different viscosity than regular oil" and because of that, "synthetic would cause the seals to leak".

I'm unconvinced.

Also claimed replacing gear sensor/switches might lead to a cascade of changes in the transmission.

"I've been doing this for 15 years, and the biggest mistake I see is people start to replace parts on/in the transmission when the transmission isn't broken."

Of course, he also admitted that there's no way to diagnose if something is in the process of going wrong in the transmission without disassembling it....

Also, if someone could check my facts and figures,
it's my understanding that the '02 MDX has 9 quarts of ATF, 5 of which drain out during a drain-and-fill.
This means that after the first D&F, 4/9 of the old fluid remains (44.44%).
D&F again, and (4/9) * (4/9) leaves about 19.75% old fluid.
the third D&F would result in 8.78% of the old fluid remaining in the system.

But I always see "3x3" fluid changes which suggests that only 3 quarts drain out.
This yields 6/9 old fluid after the first D&F (66.67%)
(6/9) * (6/9) after the second D&F (44.44%)
and after the third D&F, 29.63% old fluid.

Can anyone help me out here?
All I know is that my 2002 TL transmission (owned since new) needed 3 transmissions using Honda fluid before I finally dumped it last year.

On my 2004 MDX (owned since new) I use the Valvoline Max Life ATF (I think it's synthetic) that says it's good for honda's requiring ATF-Z1 with no problems so far. It says on the valvoline bottle that it will not void manufacture warranty.....if that means anything, I don't know. I change the transmission fluid out every year on the MDX regardless of mileage with the Valvoline - 4 drain and refills. Requires 3 one gallon bottles (3 quarts each drain) and costs about $60 in fluid - a little less if I catch it on sale. I only have 105,000 miles on the MDX but am hoping to keep this vehicle as long as possible. The transmission seems to be doing fine and does not leak.

I've seen lots of people writing here on the forum and other places about not changing fluid on a transmission that has not been serviced regularly....some people and even experienced mechanics seem feel strongly about that.....I've opted to change my fluid often with my MDX. For me in the end, it's all guesswork.
 

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You are wrong about 5 qts draining unless 02 MDX is different from 03-06 MDX. From shop manual, only 2.9 qts of 7.7 qts total capacity are drained by a drain/refill.

If you want to drain all ATF, you can but it's a bit if work. See following link.

https://www.youtube.com/results?search_query=10+min+automatic+transmission+fluid+flush

It's same process for a MDX except ATF cooling hose locations are less friendly.

I went w/ drain/replace at 30K miles interval and have had no problems despite a constant slight whine from trans at speed.

good luck
 

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+1 here on the Valvoline Maxlife Dex/Merc. Though this isn't a direct comparison, I've run the Maxlife fluid on my '05 Pilot later in its life when I had it, and I had no issues with leaks. I believe that Valvoline claims the Maxlife fluid has some seal conditioners to help keep them from leaking. I actually preferred the way the transmission shifts felt with the Maxlife vs. the Honda fluid.

I switched to Maxlife on that vehicle for a few reasons:
1. The Honda Z-1 ATF didn't hold up well when changed at the recommended interval;
2. Lots of other Honda owners had tried it with success, especially Odyssey owners who had problematic transmissions;
3. I could get it for much less than the Honda fluid; and
4. the Maxlife also works for my other car which has a Nissan JATCO RE5R05A transmission.

I don't know how well the newer Honda DW-1 ATF fares vs. the Maxlife, but I'd expect that it's noticeably better than the discontinued Z-1 originally spec'd for the '02 MDX. Whether you choose the Honda fluid or an aftermarket ATF, I believe that the key here is to change the fluid on a somewhat frequent basis. Old, tired fluid in these transmissions contributes to shudder, which I believe causes more wear on the transmission's friction surfaces.

As for the pressure switches, I'm a strong proponent for changing them out. The way that the pressure switches are designed, they wear out over the thousands of cycles they go through. When that happens, they lose their calibration and function at pressures that are out of spec. And a lot of the time, the transmission will not report an error code even though there are symptoms that they're not properly functioning. If you have some time to do a LOT of reading, check out a few threads in the 3rd Gen TL section of the acurazine forums.
A-110: DIY Guide to replacing 3rd & 4th gear pressure switch for 3G TL (2004-2006) - AcuraZine Community
Very interesting conversation with my transmission builder on the TL - AcuraZine Community
Very interesting conversation with my transmission builder on the TL - Page 14 - AcuraZine Community

I wouldn't wait for the pressure switches to "break". To me (and many of those 3rd Gen TL owners) they're more of a maintenance item that can be addressed easily and at a relatively decent cost. The pressure switches are mounted externally on the AT case and shouldn't be too hard to access. If you shop around the parts in total should come out to under $100.
 

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Discussion Starter #5
Thanks Emmet.
I'll certainly read through those links.
Sometimes "an hour in the 'library' can save you a month under the hood".

Can you describe what you mean by "didn't hold up well"? Was the fluid darkly colored, the viscosity of the fluid noticeably diminished, the presence of metal dust apparent, or was it just a noticeable decrease in the proper performance of the transmission?


I went on a drive the other day, and noticed the persistence of a ... skip, or lunge, or other type of cough/hiccup. I kept an eye on the tachometer, and at highway speeds it was hovering around 2000, and when the issue took place, the tachometer suddenly either jumped up or fell about 500 rpm.
After watching that for a while, I shifted from D5 into D4 and the problem seemed to go away or be significantly diminished.
I don't know enough to know if that data tells me anything useful.
 

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Can you describe what you mean by "didn't hold up well"? Was the fluid darkly colored, the viscosity of the fluid noticeably diminished, the presence of metal dust apparent, or was it just a noticeable decrease in the proper performance of the transmission?
I used to follow Honda's old guidelines of a ~3.5 qt. ATF change every 30K with their old fluid. As I put more and more miles on the replacement fluid I would notice a small difference in performance change. It seemed to me that the shifts would take longer and be more drawn out; after the fluid change, things would improve a little bit.

But I also noticed that when following Honda's recommendation, the fluid would be very dark at the end of the interval and that there would be a good amount of material stuck to the magnet on the drain plug. I think that aftermarket synthetic ATFs did not darken as much and left the magnet cleaner.

So my opinion is to change the ATF more frequently than Honda's recommendation. If you check out the Used Oil Analysis section of Bobistheoilguy.com, I think there are a few members who post the lab analysis results of the ATF they run in their Hondas. I believe that they recommend a mileage interval at least 1/4-1/3 less than Honda's recommendation for ATF changes.

Personally I don't think it matters which ATF you use as long as it states it can be used in an application calling for the Honda Z-1, and that you keep the fluid in the AT pretty fresh.

I went on a drive the other day, and noticed the persistence of a ... skip, or lunge, or other type of cough/hiccup. I kept an eye on the tachometer, and at highway speeds it was hovering around 2000, and when the issue took place, the tachometer suddenly either jumped up or fell about 500 rpm.
After watching that for a while, I shifted from D5 into D4 and the problem seemed to go away or be significantly diminished.
I don't know enough to know if that data tells me anything useful.
It sounds like you might have some some issue with the lockup of the torque converter clutch. Since you said you don't know the maintenance history, I'd start with doing multiple fluid changes if I were in your shoes. Some people like using the Maxlife ATF here because it works pretty well, it's pretty darn cheap, and you do end up throwing out a bunch of it anyway.

I'd then look at changing out the pressure switches, as they do wear out and the vehicle is older. If those don't help, you might have an issue that is potentially more serious. After all, only the previous owner(s) know(s) how the transmission was treated.

This may not be directly applicable to your situation, but here is another link if you want to do some more reading.
Sporadic vibration at low speeds - Honda Pilot - Honda Pilot Forums
 

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Discussion Starter #7
Super.
Went to the Honda dealer today, and one of the friendlier guys was there.
Ordered a power steering hose I may or may not need, both pressure switches, washers, and an ATF drain plug washer.

The switches I got were P/N 28600-P7W-003, which got "upgraded" to 28600-RKE-004 for #16 on the diagram.

and

P/N 28600-P7Z-003, which got "upgraded" to either the 28610-RKE-004 or the 28610-RAY-004 for #17 on the diagram. I got the RAY part.

I'll try to measure the on/off triggering pressures if we can figure out an accurate way to pressurize and depressurize the switches over here, and measure the resistance when contact is made.

Didn't get the transmission filter since I was running out of cash - maybe after I do a fuid change and run it for a while.

Then I stopped in at the local transmission shop that comes highly recommended, and spoke with the guy who runs the place. He was very kind and helpful, and took the MDX out for a ride to see how it felt. Said the trans felt like it shifted fine, and the cough I felt may or may not be transmission related - could be an engine misfire or something.

So I'm gonna take a look at the MAF, EGR, PCV, and stuff like that.
Got cheap NGK copper core plugs in it right now, so I might take a look at cleaning up the Bosch plugs that I swapped out.
Got 1/2 a tank of Mobil 93 octane gas.
Gonna see about doing a 1x3 on the trans fluid. He recommended Amalie, Wolf's Head, or Valvoline Maxlife to start off with. Apparently my trans has the oil jet kit in it, so I need to consider my options for adding in the new fluid.
He even said if I filtered my old fluid, that we could look at any particles under the microscope. Pretty impressive service, and he hasn't charged me a dime yet.
"You'll be here at some point." Sad, but true.

Looking forward to getting that all done before I take a 5-hour drive this weekend. Maybe I'll see a difference in the shift feel and see what's up with that little cough.
 

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Discussion Starter #8
OK, got to measure the new switches quicker than I expected.
3rd gear switch (spec = 33 psi) ON = ~37 psi, then switches back off at ~23-25 psi.
4th gear switch(spec = 27 psi) ON = ~30 psi, then switches back off at ~20 psi.
We just used the regulator knob on a small air compressor to raise and drop the line pressure with the switch screwed into a coupler to get a rough reading.
Both switches had around 0.3 ohm resistance when on - so they're basic on/off switches.
I saw a spec for 12-25 ohm - I don't know where that came from or if it was a measurement someone made.

Very interesting conversation with my transmission builder on the TL - Page 14 - AcuraZine Community
 

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Got cheap NGK copper core plugs in it right now, so I might take a look at cleaning up the Bosch plugs that I swapped out.
For as long as I can remember, Honda/Acura has always used either NGK or Denso plugs and I think they're worth it. According to the owners manual, Acura calls out NGK PZFR5F-11 or Denso PKJ16CR-L11. Other spark plugs might work OK, but I think the two plugs recommended by Acura should be pretty much a sure bet.

Gonna see about doing a 1x3 on the trans fluid. He recommended Amalie, Wolf's Head, or Valvoline Maxlife to start off with. Apparently my trans has the oil jet kit in it, so I need to consider my options for adding in the new fluid.
I think your two options are:
1. Get a crows foot wrench to undo the oil jet kit from the fill hole. I'm not sure what size you need here.
2. Get some small tubing, hose, or funnel and fill through the dipstick hole.
 

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Discussion Starter #10
I see.
The Autozone guy was giving me this line about how the recommended plugs are platinum or double-platinum.... I told him I couldn't afford to even have a wallet, and if I did, it wasn't platinum plated, so the spark plugs weren't going to be either. So I got the NGK ZFR5F-11's.

The guy at the transmission shops was saying something about how the engine runs pretty lean, and the leaner it runs, the higher the voltage required to produce a spark or get it to ignite the mixture. Supposedly that's why the plugs are in those those tubes, because it's difficult to make wires that won't arc at those voltages. And he seemed to think that might play into why platinum-ish plugs were recommended as well. Dunno if any of that is true, or it's all just marketing rainbows and unicorns.
I think the oil jet is held in by a 10mm bolt - so it might come out with just a long extension. Thanks for the tips.
 
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