[hokiefyd]

Does the ZF/3.x fluid seem to "degrade" quickly like the old Z1 and DW-1 fluid seems to do? With our older 5-speed autos, I do a spill-and-fill once every 15k miles or so and you can definitely feel some of the shifting that may have become a little tight or sloppy over time get cleaned up a little bit with the fresh fluid. Is the ZF 9-speed trans similar?

 

[hokiefyd]

FCA builds and programs the ZF 9 speed on their own, the Honda ZF is built by ZF and programmed by ZF so that is probably why Honda has had better reliability and drivability.

The ZF 9-speed is an interesting thing -- both from a mechanical design perspective and from a powertrain integration perspective. From my understanding, ZF provides a basic software package in the onboard transmission control module -- whether the transmission is built under license by Chrysler or built by ZF itself and delivered to an OEM. I think the "basic software package" is a very fundamental package that will provide only basic functionality of the transmission (probably basic range selection and prevent it from over-speeding itself, etc.). I understand that it's up to the OEM to provide the final software configuration and shift schedules, whether that's Chrysler, Honda, Land Rover, Nissan, or any other customer. However, since Chrysler does build these under license and (I think) has some internal design differences, perhaps its software programming is a special kind of unique.

Honda seems to have tamed this transmission in the Pilot, Passport, and Ridgeline with software updates in the 2019 time frame.

For what it's worth, I originally avoided the Pilot when we were looking for a 3-row SUV in late 2019, mostly due to the large number of complaints about the ZF transmission (and the fact that only the ZF came in the trims we were interested in). We bought an SUV from a different brand in early 2020, but sold it in December 2021 due to reliability problems, so we were back to the drawing board. I reluctantly drove a Pilot and was pleasantly surprised at how well the transmission behaved. In fact, this awful experience I had built up in my head was a total non-issue, at least in our car. We did drive it about 20 miles on the test drive. I wanted to try interstates, rural highays, stop-and-go, etc. I am very pleased with how it shifts in almost all cases. The downshifting does take some getting used to because of how the computer has to rev-match the engine in many cases (you don't get that instant engine braking you'd normally expect).

Nissan is using it in their new Pathfinder; I'm curious to see how it fares for them. The new MDX has gone to using Honda's 10-speed in all models; I presume the 2023 Pilot will have the same. My mother-in-law's 2019 RDX has the 10-speed and it's fine, but I don't think I'd necessarily choose it over the 9-speed. It starts in 1st gear (which is very short), so you always have an immediate shift into 2rd gear. I presume this is just how they programmed it -- maybe this 10-speed starts in 2nd gear in other applications. The 9-speed in the Pilot starts in 2nd gear unless you manually select 1st. And 2nd gear is still shorter than 1st gear on the old 6-speed, so I rather like this arrangement. It operates like an 8-speed auto with a granny 1st gear if you really need it. It'll get 9th gear at about 65 mph or so and it cruises very nicely at under 2,000 rpm even at 75 mph.

 

[hokiefyd]

I didn't mention it earlier because I presumed it was specific to the application but I, too, do not like the "firm" shifting of the 10-speed in the RDX. It's crisp to be sure, but I just don't care for it. I find the 1st gear start to be unnecessary in almost all situations. It's usually shifting into 2nd gear after only 20 feet worth of roll-out. I rather like how the Pilot starts in 2nd unless you manually select 1st. It does seem like the 9-speed's shift smoothness is over on the other half of the scale from the 10-speed: really, really smooth. Perhaps too smooth for some people (mushy?). I imagine a lot of this is to make the shifting feel consistent, because a longer shift is mechanically required on 4-5 and on 7-8. I think it's appropriate for the segment, though, and it's never seemed "confused" to me. You can sometimes get a transmission to not know what it wants to do, especially in cases where you immediately lift off the throttle after medium-to-hard acceleration right where you think it might want to shift. The ZF...or Honda's software...or both...seems to be pretty polished to me.

 

[hokiefyd]

TL;DR - Upshifts on the 9-speed should feel very normal. It's downshifts from 8th or 5th when some people will notice the delay (or a sensation of acceleration when using engine braking while coasting and manually downshifting from 8th or 5th even though the vehicle isn't actually accelerating - it's simply stops decelerating as quickly which humans interpret as acceleration).

Yes, you're right, and thanks for this clarification. Upshifting does feel pretty typical. The downshifts are what feel a little unusual, with those dog clutch transitions.

 

[hokiefyd]

Also in my situation the early 9 speeds 2014-2015 Cherokees there were snap ring failures so FCA programmed out the 3,2,1 downshift to prevent the snap ring from breaking , it does not downshift to second gear when stopping you have to come to a complete stop and it goes from 3rd to 1st skipping 2nd. If you don’t come to a complete stop and go to accelerate it doesn’t know what to do and bangs into gear and can snap your head back, this was their non mechanical fix that made things worse.

Wow -- that does seem like a curious response to the snap ring issue! I can certainly see how that'd be a very ungraceful behavior for the transmission.

I have never seen 9th gear and it is a very small minority on the KL Cherokee forum that have actually ever seen 9th gear.
The FCA 9 speed starts in first gear except if put into Snow Mode it starts in second to prevent wheel spin, and I will bet the Honda ZF does the same in Snow Mode to eliminate that steep first gear.
so yes sounds like Honda and ZF have done a better job.

This is also curious -- to have a final drive ratio so tall that the customer never makes productive use of the 9th speed. I have heard this -- that you have to be going like 80 mph to ever see it, and then it'll usually downshift back to 8th with any real load.

The Pilot starts in 2nd gear in all iVTM-4 modes (normal, snow, sand, etc.) if the transmission is in D mode (normal drive). If you put it in S mode, it will start you in 1st gear. 1st gear is really short, and the WOT upshift is at something like 25 mph. It's really short!

 

[hokiefyd]

The info I found from Honda states that snow mode is the only mode that starts you off in 2nd gear

In practice, the normal mode also starts in 2nd gear, in addition to snow mode. I said earlier that all the iVTM-4 modes have a 2nd gear start as long as the range selector is in D, but perhaps the sand and mud modes so give a 1st gear start. I haven't tested those enough to remember specifically where the transmission starts.

 

[hokiefyd]

Interestingly, it seems that some of the Jeep models are programmed for a 2nd gear start as well.

9 Speed Woes

Deleted by User. Deleted by User.

www.myjeepcompass.com

 

[hokiefyd]

Here's a Passport 0-60 run filmed, but starting in D instead of S (so it's a 2nd gear start).

First video, driven in S mode: 1-2 shift at about 25 mph; 2-3 shift at about 42 mph
Second video, driven in D mode: 2-3 shift at about 42 mph

 

[hokiefyd]

ZF Friedrichshafen AG builds them but the individual manufacturers have the ability to program the TCU. Physically they are the same, but operationally they are different based on the programming.

FCA builds the 9-speed under license from ZF and there are actually several significant mechanical differences between a ZF-built 9HP48 and an FCA-built 948TE. This PDF has a good overview of those differences.

You are correct that each manufacturer programs the TCM. I imagine FCA's problems may have been poor programming compounded with poor design and engineering variations from ZF's original design, even if done with good intentions. Honda also had problems with them early on, but software programming updates seem to have resolved those.

I'm kind of a transmission snob...I'm very sensitive to shift quality, shift scheduling, etc. I rarely find an automatic that I really like, and our 2005 MDX's 5-speed is about perfect for me. Having said that, I'd describe our experience with our '22 Pilot's 9-speed so far as excellent.

 

[hokiefyd]

Interesting, didn't read all 29 pages yet, but looking over it, it seems that most of the changes are more on the line of cosmetic/fitment changes. It still seems to function in the same manner. I do like the Park Shift Lock release being manual instead of the Honda/Acura accessory tool,

Yes, for sure, the basic functionality is the same. They're just not physically the same transmission. Here's a good resource that shows some of the physical changes FCA made:

Ray’s Garage: ZF HP9 vs Mopar 948TE

How are the Chrysler-built and ZF-build nine-speed automatics different? This is a question that was answered in general at Allpar some time ago, but Raybestos has taken apart both transmissions and analyzed visible differences in a video. Raybestos’ Irvin Gers and Dan Truncone presented...

www.allpar.com

 

[hokiefyd]

(no "enhanced drivability and smoother shifts" or second-gear starts for the 2019-2022 model years)

I was not aware that the 2nd gear start came with the software update Honda offered in 2019. So the 2016-2018 cars with the 9-speed start in 1st gear? Good to know!

 

[hokiefyd]

Between speeds 4-5 and 7-8, ZF uses dog clutches instead of friction clutches to save space.

I think I know what you meant, but just for the sake of completeness...both dog clutches are used (engaged) in gears 1, 2, 3, and 4. During the 4-5 upshift, one of the dog clutches disengages, while the other stays engaged...and it stays engaged in gears 5, 6, and 7. Then it disengages during the 7-8 upshift, after which neither dog clutch is engaged. And then, of course, the reverse is true when downshifting...one of them engages during 8-7 and stays engaged downward from there...and the second one engages during 5-4, and stays engaged downward from there. The dog clutches aren't used just during those two shifts.

As a point of interest, this transmission defaults to a 2nd gear start in D mode (at least I think 2019 and later does, or an earlier model after the software update has been applied). You can't even tap it down into 1st gear with the left paddle if you're in D. You have to switch to S mode to get 1st gear. So if you're counting shifts in D mode, you'll feel only 7, and it uses 8 of the 9 gears in D mode. As I recall, the overall drive ratio of 2nd gear in the ZF9 is still shorter than 1st gear in the old H6 auto, so it still launches off the line strongly in D mode. In S mode, starting in actual 1st gear, it'll really take off!

The dog clutches are released during upshifts and applied during downshifts which results in a bit of a delay and unconventional feel when downshifting from 8th and 5th.

Yes, and I think Honda's done a remarkable job here with the shift programming to get all shifts to feel just about the same (I think this was largely what the 2019 recalibration brought to the picture, in addition to the 2nd gear default start noted above). The engine speed necessarily has to flare/blip during the 8-7 and 5-4 downshifts...and Honda's sort of matched that behavior across most of the shift range, so 8-7 and 5-4 don't feel so out of place. And, in practice, it's something that feels odd for the first few drives, and then you get used to it. We have one Honda with the ZF9, and our other two have old school Honda H5 automatics, and it's easy to move back and forth without having to change driving style.

@Jimmy James I agree, the shifts are nearly imperceptibly smooth with this transmission. Intuitively, you'd think that means it's really tearing up its clutches or working its fluid hard, but anecdotal evidence suggests these transmissions are at least as durable as the H6, especially when it comes to torque converter operation...an apparent weak area for the H6.

 

[hokiefyd]

Is it normal to hear a clunk like noise on the 4-5 and 7-8 shifts?

You generally shouldn't hear anything during normal driving. Some have reported that having a transmission cooler installed can cause a buzz noise during the 7-8 shift (and maybe during the 4-5 shift too, I don't know). But if you don't have a cooler installed, you shouldn't heard a clunk noise.

 

[hokiefyd]

but there does look like a metal mesh screen filter.

This is not unprecedented, and may not even be uncommon. I once owned a Cadillac with the Northstar engine and GM's 4T80-E transaxle and a GM powertrain engineer participated on one of the Cadillac forums I followed at the time. When the topic of fluid filtering came up, he described it very similar to what's in the ZF transaxle -- a fine mesh screen that's not designed to be serviced. I couldn't know the efficacy of this myself but, for what it's worth, those 4T80-Es would last a VERY long time, so it doesn't seem like that filtering approach was detrimental to the system.

...why did Honda elect not to use a dipstick like Chrysler did

I don't know for sure, but I'd say Honda's following a general industry trend, especially with transmissions and transaxles, to remove the temptation for users to service them at home. There's the very real risk of the wrong fluid being used (it happens all the time, either by intention or by accident) and these systems seem to be increasingly sensitive to fluid quality and characteristics.

For the keen DIYer, though, this isn't a real impediment, and there are several threads here on how to get it done. Rather than a dipstick to check level, you use the fill hole. It's really not much different in practice -- as you still have to do it when the fluid is in the correct temperature range -- whether you're reading a stick or checking the sump level with the fill hole. One's just easier than the other, and I suspect Honda took the dipstick away so the casual observer would think, "huh, I guess I won't try this myself."

 

[hokiefyd]

I think that entire black plastic housing is the filter assembly, at least the way I'm interpreting it. That clear pipe he pulls off is the secondary feed for the pump or whatever he described.

The large tube with the metal o-ring -- that appears to me to be the main fluid feed either to or from that filter assembly.

 

[hokiefyd]

We have nearly 14k on our 2022 model and I'm very pleased with this transaxle so far. I was hesitant on it, given all the negative early press, but I'm pretty impressed with Honda's current software on this. I usually like Honda's shift programming in general...being pretty happy also with our '05 MDX and '09 Ridgeline (which both use 5-speed Honda autos).

The only thing I wish was different about the ZF9 is the delay between shifting from P or R to D. There is some dog clutch action going on here as well. The A dog is not engaged in P and R...but it is engaged in forward gears 1-7. So the shift from P or R to D must engage the A dog, and I presume this might take some trickery because, with the car stopped, the only thing in the transaxle that's moving is the torque converter turbine (I presume the input shaft is not turning when the car's stopped). I think that's reason for the delay that can sometimes be annoying.

Otherwise...I really like this transaxle.

 

[hokiefyd]

In theory, they could open up the transmission, diagnose the problem, and replace only the part that needs replacing. However, this requires quite a bit of skill (and likely special tooling), and an absolutely clean and sterile environment...none of which usually exist in a dealership's service bay.

(I don't say that as a knock against service departments -- there's just no value proposition for them to invest the time and resources into building such a knowledge base and skillset for something that's needed relatively infrequently.)

From a warranty perspective, it's less expensive for the automaker to rebuild transmissions in a controlled environment and just exchange them as commodity items if one fails in service, which is why this pretty standard industry practice has developed.

Gone are the days when your local GM dealership is opening up that TH-350 to replace a band or clutch, for better or for worse.

 

[hokiefyd]

I am not sure this transmission was meant to be starting on 2nd gear when designed but for sure feels under powered to me from stop specifically going uphill. What is your experience?

I think acceleration from a stop in 2nd gear is pretty strong. Heck, published 0-60 times are in the mid-6 second range, which is pretty darn fast for a 4,300-lb SUV with only a V-6 engine. Looking at some math:

The ZF 9-speed's final drive ratio is 4.33:1 and the 2nd gear ratio is 2.84:1, making for an overall drive ratio of about 12.30:1.

In comparison, the Honda 6-speed's final drive ratio is 4.25:1 and 1st gear is 3.36:1, making for an overall drive ratio of about 14.28:1. So it's shorter than a 9-speed's 2nd gear by about 15% or so.

Our 2005 MDX's 5-speed's final drive ratio is 4.38:1 and 1st gear is 2.69:1, making for an overall drive ratio of about 11.78:1. So it's taller than a 9-speed's 2nd gear by about 5% or so.

By the math, this puts the 9-speed's 2nd gear ratio somewhere in between the 5-speed's 1st gear and the 6-speed's 1st gear, which I think is reasonable. The 9-speed's 1st gear is a ridiculous 4.71:1. Multiplied by the 4.33:1 final drive ratio, and you get an overall ratio of over 20:1. That's so short, the transmission has to shift out of 1st pretty quickly after you get moving, which is pretty disruptive to a smooth drive. It's actually one of the things I don't like about Honda's 10-speed...it doesn't use a 2nd gear start and the 1-2 shift happens like halfway through the intersection after you step off from a stop sign.

 

[hokiefyd]

Car and Driver, whose performance data is often unrealistically optimistic and performed by professional drivers on a closed course and "adjusted for conditions", measured a 2022 Pilot at 6.7 seconds 0-60 including 1-ft rollout. Consumer Reports, whose performance data is much more realistic, measured a 2022 Pilot at 7.5 seconds 0-60.

Motor Trend got 6.2 seconds out of a 2019 model: https://www.motortrend.com/reviews/2019-honda-pilot-vs-2020-ford-explorer-comparison/

Regardless, my point was that it's competitive and usually at least mid-pack in a comparison test. The 2nd gear start should not make it feel lethargic.

 

[hokiefyd]

I believe that was a Passport that MT measured calculated a 0-60 time of 6.2 seconds.

It was a 2019 Pilot; I provided a link to the article. Regardless (again), my comment wasn't intended to cite a particular guaranteed performance number (which is why I didn't even give a specific number)...rather, the Pilot does not struggle with the gearing setup Honda gave it.

I withdraw my statement, counselor.