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Transmission Makes Abrupt Upshifts - 2015 Acura TLX SH-AWD Long-Term Road Test
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Transmission Makes Abrupt Upshifts - 2015 Acura TLX SH-AWD Long-Term Road Test
The new nine-speed automatic in the 2015 Acura TLX exhibits some unusual abrupt shifting in low gears when cold.
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http://www.zf.com/media/media/en/document/corporate_2/products_3/innovation_1/9hp_1/brochure_9hp.pdf
When saying that the 2-3 shift isn't smooth, are you checking to see if that's the actual 2nd to 3rd gear or just the 2nd and 3rd shift from a normal stop? If you're driving easy and Honda/ZF have it programmed to start in a higher gear you'll experience a slight delay in shift as the transmission controller brakes and times the engagement of the dog clutch that engages between or passing through the 4-5 gears (also between 7-8), at which time there's also heavier torque management to keep input torque down.
For the other gear changes it uses the normal clutch-to-clutch shifts of the planetary gearsets which happen almost instantly, but due to having to switch between the planetary gearset (there are four, two main that each have another nested planetary gearset inside them) and use of dog clutches (which are essentially on-off only by design and can't be slipped like a friction clutch) it takes more time to engage.
From a technical standpoint there's nothing wrong with this design and it allows ZF to cram a lot of ratios in a very small transverse application. They could probably get just as wide an overall ratio spread with less gears but the extra gear count allows the automaker to use the design and tailor shifts and gears ratios to better match up with engine torque characteristics for better economy.
Down side is that the transmission behaves "different" than what people are expecting and not every gear change will feel the same. Chrysler has had a lot of teething issues and I'm guessing the updates to the transmission calibrations have been a combination of improvements ZF is making to the timing of the dog clutch engagement along with the automaker trying to mask this somewhat by altering torque management (output) of the engine calibration during shifts and better predictive timing of shifts under changing vehicle loads.
It is logical to an engineer and the operation would make perfect sense but try explaining it to an average consumer that only knows something is different or doesn't feel right on some shifts compared to others. If ZF and the automakers can't get the complex powertrain controller calibrations refined enough to mask the operating characteristics I expect this family of transaxles will be short lived.
But then I'm a weirdo when it comes to transmissions. My own car has the Fiat DDCT that strikes fear into the hearts of the uninitiated, and I also happen to like CVTs! :P
I am an owner of a '15 TLX SH-AWD model. I hate this transmission. I was ignorant enough to believe that Acura had thoroughly tested this car/transmission, which is supposedly why they held back on its' initial release.
I have had 3 software updates and not one has helped. The main issues I have with this transmission and setup are:
1. The absolute horrible hesitation when accelerating from low speeds. Try exiting a corner and giving the car some gas.. it bogs down instead. I have an SH-AWD for Christ's sakes!
2. The hard shift between 2nd and 3rd gear. And since th34 last update, a hesitation if I am slowly cruising up to lower speeds. (under 30 mph).
3. The Idle Stop "feature" when disabled via the on-off button, causes a hesitation during near stop (AKA rolling start/California stop) accelerations where the engine revs but the car has not shifted down to 1st gear, or even 2nd gear, then the transmission seems to realize it needs to do something and downshifts, causing the car to lurch forward. If I come to a complete stop and wait a few seconds, the car works normally.
To say I have HUGE regrets in this car is an understatement. I want to love the way it looks, handles, rides on the open highway but.. this transmission made this a short honeymoon. I have had this car since Dec. '14.. 10 months of this issue and no end in sight.
I've got an 2009 Civic and I've experienced a similar sensation with mine, except when shifting from 1st to 2nd gear when driving from a cold start. The transmission seems to hang on to first gear for a bit too long and then slams into 2nd. It only happens a few times before the transmission gets warmed up, but I've noticed it in colder weather.
I tried some ZMAX transmission additive that a friend of mine recommended after having good luck with it in her own car. It did smooth out gear changes a little bit, but time will tell if it still shifts roughly at warmup once the weather starts to get a bit colder.
If you have a transmission that isn't shifting correctly you'll almost never "fix" anything with a pour-in solution. It may mask the symptoms you're experiencing but is the additive causing the internal clutch packs to slip more masking shift harshness but increasing heat and reducing service life? On designs that use planetary gearsets where it's possible different gears could be engaged at the same time but only the trans controller prevents that by disengaging the clutch for one gear before engaging the clutch for the next gear, if this happens on the order of milliseconds and you modify the fluid so it causes the clutches to grab and disengage slow, what if you get wear from overlapping clutch engagement due to improper fluid?
Those are just a few examples. Often just installing a universal automatic trans fluid can cause shifting on some cars so I definitely wouldn't want to put an additive in unless it was tested and recommended by the manufacturer. There are some fringe cases where fluids change over time and after a lot of real-world testing by private owners an alternative fluid has been found to work but that can be risky. If a transmission isn't shifting correctly it's usually best to ensure it has the correct amount and correct fluid and if it isn't shifting right it could either be a design characteristic, a problem such as internal mechanical wear that a Band-Aid fluid won't fix, or a software or sensor issue with the control module for the trans.
Same thing with each evolution and additional number of gears. Most transmission developers are saying we're getting to a physical limit with planetary gearsets as the complexity to make smaller parts that can still stand up to the same input torque (i.e. engine power) and cost becomes prohibitive. The ratio spread, from lowest to highest gear ratio also isn't improving much so it likely is about the end once we hit around 10-speeds with the current packaging requirements.
These transmissions give a wide ratio spread and offer enough gears and flexibility to offer a better range for the load and operating conditions to provide the best acceleration or economy. The constantly variable transmission (CVT) have an advantage in that they normally have less pumping losses (conventional planetary gear transmissions require a bigger hydraulic pump to control the hydraulic circuits that engage and disengage gears and the bigger pump requires more engine power to drive it). The CVT can also has an infinite range or ratio it can select from within its ratio spread determine by the input and output pulley size. This allows the powertrain controller to select the best engine operating rpm for power or economy, then hold the engine at that range and use transmission effective "gear" ratio changes to accelerate the car.
By having 8, 9, and soon 10-speed transmission the engine rpms still have to increase while in a gear in order to accelerate, but because there are many smaller gear ratios that are closer together the engine can be operated in smaller and smaller rpms ranges while the gears are changed to accelerate the car. This can greatly help with economy under certain conditions and also improve acceleration. But just like the CVT, which behaves "different" than most consumers are expecting, when you have a transmission with a lot of gears or technical changes like different internal gear engagement clutches like on the ZF-designed transmission in the TLX, it doesn't matter if the transmission is reliable and working technically as designed, the consumer has to adapt or sale will suffer.
Another example of this is when the VW Group first introduced their dual-clutch transmissions (DCT), where you essentially have two manual transmissions that connect to the same output shaft that is driving the car's wheels. One clutch engages the first gear, then when you shift another gear on the other shaft has already been selected and the first clutch disengages and the clutch for the second shaft and gear engages. This allows for reduced pumping losses with a smaller hydraulic circuit and smaller pump and less friction losses due to a simpler design.
When that design first came out many early adapters liked the novelty and understood they were getting something new and different while other consumers just wanted "conventional", "normal" automatic transmission, didn't know it worked different and complained. VW went back and refined the design, making small changes to the internal components and worked on the software calibration that controls the operation. Over time consumers were educated to the DCT advantages and marketing sold it as "better", which pacified some of those potential buyers that might otherwise complain. They also made it act more like a regular planetary automatic with smoother launching from a stop and gear changes.
The problem with the ZF 9-speed is that it's a good technical solution to cramming lots of gears in a small package but it works different. Unfortunately there isn't anything really special or "different" to get early adaptors willing to tolerate it and they can't market it as special because most consumers wouldn't have a clue about the difference between dog and conventional friction clutches, blocker rings, etc. If ZF and the automakers can improve the design and especially the software to mask the unique operating characteristics it may prove to be a reliable transmission that nobody things about. Unfortunately the media is hammering the point that there have been problems but hasn't been good at explaining that it might not be mechanical reliability issues but instead operational characteristics.
One last comment transmission and transaxles, it's easy to speculate that Honda "couldn't afford" to design another transmission but you have to look at what afford means. Financially? Engineering resources? Timeline to get it to market? Honda very well could have had all the time, money and manpower to develop a transaxle for their TLV and V6-powered cars in house looked at what was available on through suppliers and found it cheaper and faster to use an already developed solution. That takes nothing away from Honda and makes smart business sense.
It's also not as easy to say that xyz automaker "builds" their own transmissions. Some automakers design and build entire transmission assemblies in-house. Others license a design from a supplier and build it in their own factories. An example would be the ZF 8-speed transmission used in rear drive applications. The build some of them and supply it directly to automakers while others take the design and build it in-house. Some automakers form joint ventures with other automakers to design a transmission, such as Ford and GM working on a common 10-speed design that will be built by each automaker but packaged into a unique housing and have unique electronic control and tuning.
There are other joint ventures such as GETRAG Ford Transmission, which builds Getrag-designed transmissions such as the dual-clutch PowerShift used in the Focus along with manual transaxles that were designed with input from both parent companies. The automotive landscape is evolving and it's not as simple as many people think. New Venture Gear is another example where Chrysler, GM and Ford formed a joint venture using sections and plants from each company to design and build transmissions and transfer cases.
A person could look down on Chrysler or Honda for using the ZF 9-speed as some lack in ability to build one themselves, but they've both designed and manufactured their own transmissions, some of which have also had teething problems and some that have been great from the start. The same thing with suppliers, transmission companies and joint ventures; some designs are better than others and sometimes there are problems that correctable and sometimes not without a complete redesign. I'm under the opinion that the ZF 9-speed could very well prove to be a mechanically reliable and efficient transaxle but perception and operating characteristics will cause it to sink or swim in the marketplace.
Two new transmissions while also developing new turbo 4s. For any company this is very expensive and Honda is no where as big as GM or Toyota. I understand the decision to buy transmissions from ZF for V6 models because that's going to be a small volume of cars for Honda. They also probably don't have the manufacteuring capacity for more than two types of automatic transmission. But hopefully when they're able to recoup the R and D money in their new powertrains they will drop the ZF unit and build another in house replacement.
You don't have to accept the "that's the way it is" mentality, you figure out how to do it better. Honda's very first automatic transmission, the HondaMatic, was totally different than any other transmission because Borg Warner owned the patents for the basic design of an automatic transmission and you had to agree to a joint venture or pay Borg Warner a license agreement to use it. Honda at first asked BW for help because they had no idea how to build one from scratch but BW said they had nothing that would work with their tiny engine and nothing that could go to 8,000 rpms, So Honda had to figure out how to do it all themselves. What they came up with was so different that it didn't infringe on BW's patents and was the first to have a 7 position gear selector (PRND123) for full manual control (Mr. Honda highly preferred manual transmissions) and the first automatic transmission with no planetary gears. Soichiro Honda was an engineer by trade and he lead his company as an engineer not a manager. When he was asked if they could build a transmission that would avoid a lawsuit by BW he told his employees "We [Honda] refuse to depend on anyone else. We will not copy foreign products nor pay royalties for the use of other companies’ patents. We don’t intend to get support from the government, either. I’m making it clear that we will do it our way." Their new CVT and 8 speed DCT show that his philosophy may still be alive at Honda.
Don't consider a 2015. I have the 2015 v6 w/sh-awd. This 2015 version is a disaster. I drove a 2016 and the 1-2, 2-3 abrupt up shifts are much better. My 2015 shifts like the first time I tried to teach my wife how to drive a manual. It seems Acura has no intentions of making this right.
After multiple attempts at a software updates, still no joy.