[zerog2k]

The proper procedure for filling and checking level on the ZF-9 is much stricter. Essentially, it's looking at the ATF temperature (which can be found by looking at an OBD custom pid), and the procedure requires that you do the fill-and-spill between a certain temperature range (99-113 F). Anecdotally, folks have reported minor but noticeable shift quality issues when it wasn't filled/leveled per spec.
Thermal expansion may be a bigger thing with the ATF 3.1 and/or the ZF-9
Edit there are other posts around here with the factory method, along with "shortcut" methods, like using an IR thermometer to check the ATF case temperature.

 

[Nail Grease]

What does the OBD II scanner have to do with transmission service? I'm just looking for info, not disagreeing. Thanks.

One with service functions.

 

[ls973800]

What does the OBD II scanner have to do with transmission service? I'm just looking for info, not disagreeing. Thanks.

The Honda procedure to measure the correct fluid level on the 9 speed transmission involves putting the vehicle into VSA mode and several other involved steps. I don't know if the OBD II scanner would be used for transmission temperature readings or to put into VSA mode, or for both. Honda manual steps below to correctly check the fluid level on the 9 speed

1. Turn the vehicle to the ON mode. 2. Enter the VSA maintenance mode. 3. Start the engine. 4. Shift the transmission to S position/mode. 5. Run the vehicle in 1st gear, 2nd gear, 3rd gear, and 4th gear, at sequential shift mode, and wait for at least 10 seconds to each gear. Slow down, and stop the wheels. NOTE: Do not run transmission on the lift past 4th gear, or transmission damage will occur. 6. Shift the transmission to P position/mode, then raise the engine speed at 2,000 rpm to ensure that the torque converter is full of ATF. 7. Run the engine at idle speed until ATF Temperature reaches 104 °F (40 °C) (allowed adjusting range: 99－113 °F (37－ 45 °C)) with the HDS. 8. Remove the level plug (A), and make sure the ATF is dropping from the level plug hole (B) while the engine is still running. NOTE: If the ATF is pouring out, wait until the ATF starts dripping from the level plug hole. If there is no ATF coming out, add the ATF through the level plug hole until the ATF overflows, then wait until the ATF starts dripping from the level plug hole. Improper ATF level will affect shift quality. 9. Install a new level plug. 10. Turn the engine off

 

[ls973800]

But if VML is "recommended" for both DW-1 and 3.1 as alternative, then DW-1 isn't out of the ballpark for fluid characteristics, and isn't a catastrophic fail, as exhibited by the transmission shrugging it off and shifting normally. I won't join a hand wringing party, here. It's not like he poured in 3.5 qts of 5w-30 or WD-40. On the other hand, DW-1 is poison in any transmission....LOL.

I can see where the VML might have more additives and other specifications where it could be backwards compatible with the DW-1 and sufficient for 3.1 use, but the Honda DW-1 may not contain the correct additives or other secret sauce that the 3.1 needs. Almost like the latest oil rating API SP is backwards compatible with earlier oil ratings. However, earlier ratings may not be able to provide the same protection in newer engines that require an SP rating and therefore can not be used.

 

[hokiefyd]

But if VML is "recommended" for both DW-1 and 3.1 as alternative, then DW-1 isn't out of the ballpark for fluid characteristics, and isn't a catastrophic fail, as exhibited by the transmission shrugging it off and shifting normally. I won't join a hand wringing party, here. It's not like he poured in 3.5 qts of 5w-30 or WD-40. On the other hand, DW-1 is poison in any transmission....LOL.

The nuance here is the very specific chemistry of the DW-1 fluid, and long-term use of that in a transmission not designed for that. Both Honda ATFs (Z-1 and DW-1) use very high concentrations of zinc, which is almost unheard of for ATFs. I believe this is likely related to the specific needs of the clutches in the 5- and 6-speeds. Valvoline recommends its ML ATF for these applications, and it does seem to work well, but almost everyone who has used it notes the modified shift feel (usually, firmer). It seems, at least anecdotally, that the different chemistry and friction modifiers firm up the shifts. Is this preferable? Perhaps so...I'm not saying it's not. But it's different.

Does the logic chain work in reverse? If VML makes a transmission designed for DW-1 shift more firmly (and with presumably lower clutch wear), would DW-1 make a transmission designed for more conventional fluid shift differently? There's certainly way more to fluid chemistry than can be observed with an inexpensive oil analysis, so I don't think any of us really knows for sure what's in the ZF Lubeguard 9 or Honda 3.1 (presumably re-bottled ZF LG9) that make it so special. And, I don't think we know the long-term effects of using an unconventional ATF like DW-1 in a transmission not designed for that specific chemistry. It might work fine, but it may not work fine...even if the transmission doesn't ultimately reject it at first. This could also be very nuanced -- it could be the transmission clutches are much less effective with this fluid, but the software "saw" that in observed shift behavior and adjusted shift operation pretty quickly so that it wasn't observed by the driver...but perhaps now, those adjustments put it at the far end of that adjustment range, limiting the transmission software's ability to keep in a healthy balance over time. All pure conjecture, of course.

And because most of our talking points really hinge on data we don't have and can't acquire cheaply or easily, I do think the prevailing recommendation to drain as much out as possible and replace with the correct fluid is the most prudent course of action.

 

[hokiefyd]

Makes one wonder why Honda wouldn't have a dipstick?

This is very common now, and I think it's for this very reason/situation. Transmissions have become much more complex than they were in the past, and much more sensitive to fluid type, condition, etc. A dipstick is another point of entry for contaminants and potential mix-up of fluid types.

 

[Radioguru]

Regular checks on transmission levels SHOULD be observed. What's next lifetime oil changes?🤣

 

[zerog2k]

For those wanting to check the levels on the 9-speed the proper way, and not having access to HDS or other professional scantool, you can use a smartphone app like Torque or CarScanner along with most OBD dongles, to read the ATF temp.
I have a lengthy post about all of this:

Custom PIDs for ODB scantool/app like Torque or CarScanner

Just want to open a thread to capture all the various custom ODB pids known for doing your own monitoring of things which the vehicle does not natively display (like transmission temperature, etc). Background: https://en.wikipedia.org/wiki/OBD-II_PIDs Honda, like other manufacturers, use custom...

www.ridgelineownersclub.com

 

[AVC]

I can see where the VML might have more additives and other specifications where it could be backwards compatible with the DW-1 and sufficient for 3.1 use, but the Honda DW-1 may not contain the correct additives or other secret sauce that the 3.1 needs. Almost like the latest oil rating API SP is backwards compatible with earlier oil ratings. However, earlier ratings may not be able to provide the same protection in newer engines that require an SP rating and therefore can not be used.

It makes sense that VML is backwards compatible, and therefore it follows, superior to any OEM formulation (regardless when the OEM fluid was introduced, since VML's introduction 10yrs, 12 yrs ago?), and (apparently) as regularly submitted by Valvoline and certified by the API, just like engine oil.

 

[Daltongang]

Seems strange to me too but it's not the only one. A friend owns a VW Touareg diesel and that transmission has no dipstick either.

Modern higher geared transmissions are more complicated, than transmissions of old and require more precision, both in manufacture and maintenance. Horse shoes and hand grenades maintenance was fine for older transmissions, but now even the fluid levels need to be exact. Thus the reason for no dipstick, and more complicated, temperature specific drain and fill procedures.

 

[pdaiello417]

Thanks for all the responses. I went ahead and drained and refilled the transmission 3 times. Everything seems to be working great.

 

[AJ1]

I just did my own transmission service and poured in 3.5 quarts of Honda's ATF-DW1 fluid. I've been driving it around and it seems to be driving ok, but I just learned that I have the 9-speed transmission and it takes the ATF-Type 3.1 fluid. I'm assuming I'll have to completely drain all the transmission fluid out and start out with all fresh transmission fluid before something starts to break inside. Can someone help me with what the best procedure would be? Should I just drain and refill it 3 times or is there another way to get everything out?

thanks in advance for your help.

I don't know maybe at this point it might be better just to take it to the dealer tell them you want to change transmission fluid they will do the update also and they have the proper scanner. And if you ever had to change that fluid again you'll be prepared and know what it consist of. I'd actually have it towed to the dealer .

 

[2021Gets2004Pilot]

Dear PDAiello417:

I am a new member of the Piloteers, like you are. So, welcome to the club, fellow "newbie.".

You only put in a similar-but-different automatic transmission fluid, not a 100% terribly wrong fluid like "5w30 or WD-40," as the longtime member "AVC" wrote. You made an honest mistake. Please don't feel too bad, per AVC, so you don't "have to join a hand-wringing party."

The half volume draining, then refilling, of your automatic transmission, 3.5 quarts at a time, resulted in 87.5% DW-1 ATF and 12.5% of the original Honda factory installed Type 3.1 ATF.

You updated your post by informing us of how you did another three rounds of draining and refilling your automatic transmission, this time using the Type 3.1 Fluid. You are now at about 90% pure Type 3.1 (there was the tiny amount of the original Honda factory installed Type 3.1 remaining in your transmission, after you did your mistaken DW-1 three times of draining and refilling.)

I'm sorry you had to spend so much money at $20 a quart for all the DW-1 ATF, then $30 a quart for all the Type 3.1 fluid, not to mention the added time and effort. But, there's good news PDAiello417, you now have one tremendously clean automatic transmission.

"It's all good."

 

[batangboni1]

I just did my own transmission service and poured in 3.5 quarts of Honda's ATF-DW1 fluid. I've been driving it around and it seems to be driving ok, but I just learned that I have the 9-speed transmission and it takes the ATF-Type 3.1 fluid. I'm assuming I'll have to completely drain all the transmission fluid out and start out with all fresh transmission fluid before something starts to break inside. Can someone help me with what the best procedure would be? Should I just drain and refill it 3 times or is there another way to get everything out?

thanks in advance for your help.

Drain and fill at least 4 times. The drain and fill service (normal) takes about 3.70 qts and the correct level is determined by removing the level or overflow plug on the driver side of the transmission. After refilling, run the engine and cycle the transmission into the gears and with the aid of the somewhat advanced scan tool, monitor the fluid temp level. Recommended to check the level by removing the overflow plug when the fluid temp is between 98 and 112 degrees F. Any temp above that will give you a false level since the fluid volume swells as the temp rise to operating temp.

 

[Daltongang]

This is actually one of the very few times that Honda recommends a transmission flush instead of a drain and fill procedure.

 

[Hogan773]

This is actually one of the very few times that Honda recommends a transmission flush instead of a drain and fill procedure.

Depends what "improper fluids" means. Are we talking WD40 or 10W40 as improper fluid that "should be" flushed out, or are we talking MaxLife or DW-1. I'm guessing if you asked an official Honda statement they would say the latter, but in practicality, probably only the former.