[dZired]

ZF Friedrichshafen AG, the famous automotive component manufacturer from Germany, has officially started production of an all-new 8-speed dual-clutch transmission unit.

This new transmission, named 8DT, will be manufactured at the company’s production facility in Brandenburg, Germany. The company is reportedly putting in more than 100 million Euros for the production of the new 8-speed transmission.

Engineers at ZF and Porsche have collectively developed a hybrid transmission modular kit, which is based on the new dual clutch transmission. This particular modular kit will be compatible with both standard and all-wheel drive systems.

Source: ET Auto



Link to Team-BHP News

[srishiva]

Hopefully they will have the same smooth shifting nature that ZF has in normal ATs. I remember in U.S, Audi had to move to normal ZF AT since people did not like the jerky starts of dual clutch in S4.

They should also consider introducing single clutch auto shifters in our market.

[i74js]

Automatics are the future; yesterday someone shared an article from ET about the traffic density in Mumbai which is close to about 500 passenger car units (PCU) per km. It is necessary to switch from conventional gear based transmissions to auto-boxes.

Players like M&M and Tata with least investment in automatic transmissions are also looking at options to the compete in the market where other companies have their in-house automatic lineups.

I don't know but somehow I feel that extensive use of automatics also indicate market maturity as all developed economies (EU and the US) have larger share of these technologies compared to manual transmission.

Companies like ZF can certainly gain from economies of scale by tapping Indian market and car producers in India as it serves as export hub for many of them. Simple, easy to maintain and reliable automatics are required in India and I would still not consider AMT as an option for the country; it has to be the conventional automatic technology be it the torque convertors or CVT. DSG and DCT are relatively complex and may not be cost effective for entry level cars.

Cheers

[GTO]

This is certainly an odd move because:

- The current 8-speed ZF is the best automatic gearbox out there. It is simply fantastic! The gearbox scores on smoothness, response time and shift speed. Even the manual mode is aggressive. I can't think of a single downside to the current ZF 8-speed.

- Car makers like Audi & Ford are actually moving away from dual-clutch ATs due to their initial jerkiness, poor reliability & customer complaints.

Keeping that in mind, why is ZF bringing out a dual-clutch? Only reason I can think of is an order from a car manufacturer. ZF, after all, is a component manufacturer who'll give car manufacturers whatever they want.

[quickdraw]

Originally Posted by srishiva

I remember in U.S, Audi had to move to normal ZF AT since people did not like the jerky starts of dual clutch in S4.

According to this article it was because the old dual clutch couldn't take the torque. I actually have a friend who drives a S4 so i'll definitely check this out. I doubt people who buy the 'S' version cars will complain about aggressive gearshifts.

Originally Posted by GTO

This is certainly an odd move because:

- The current 8-speed ZF is the best automatic gearbox out there. It is simply fantastic! The gearbox scores on smoothness, response time and shift speed. Even the manual mode is aggressive. I can't think of a single downside to the current ZF 8-speed.

- Car makers like Audi & Ford are actually moving away from dual-clutch ATs due to their initial jerkiness, poor reliability & customer complaints.

Keeping that in mind, why is ZF bringing out a dual-clutch? Only reason I can think of is an order from a car manufacturer. ZF, after all, is a component manufacturer who'll give car manufacturers whatever they want.

I think you answered your own question there; its a logical next move. The ZF 8 Speed is legendary gearbox making its way into so many amazing cars and been perfected over the years. It should gain significantly in form of faster shift times thanks to dual clutches and I'm very sure that the amount of 'jerk' you get during shifting can be controlled via software. Lastly I'm quite sure ZF will be able to create this sans the reliability issues and make its way into some amazing cars. I doubt that a single car manufacturer can justify a 100mn investment. This too will be modular and will make its way into many different models. I'm just surprised they didn't put more gears in.

[srishiva]

Originally Posted by quickdraw

According to this article it was because the old dual clutch couldn't take the torque. I actually have a friend who drives a S4 so i'll definitely check this out. I doubt people who buy the 'S' version cars will complain about aggressive gearshifts.



I think you answered your own question there; its a logical next move. The ZF 8 Speed is legendary gearbox making its way into so many amazing cars and been perfected over the years. It should gain significantly in form of faster shift times thanks to dual clutches and I'm very sure that the amount of 'jerk' you get during shifting can be controlled via software. Lastly I'm quite sure ZF will be able to create this sans the reliability issues and make its way into some amazing cars. I doubt that a single car manufacturer can justify a 100mn investment. This too will be modular and will make its way into many different models. I'm just surprised they didn't put more gears in.

Quoting from Car and Driver
Audi says it went for the conventional automatic because U.S. customers prefer the smooth torque-multiplication effect when taking off at a stoplight, something the dual-clutch gearbox is unable to provide.

http://www.caranddriver.com/reviews/...t-drive-review

Maybe, there were multiple reasons!

[Rahul Rao]

Some time back I had seen an older BMW X5 torque converter opened up for repair at a local workshop, being interested in it the owner had called me over to have a look.

The Torque Converter had come with a lock arrangement giving it a positive drive once locked up, in BMW 8 speed with 30d the locking occurs in 2nd gear itself, though if you throttle hard it takes place in 3rd. Drive with a light foot you feel it lock at as low as 700 rpm to which RPM falls after 1st to 2nd shift. Note that 30d has idle at 600 RPM far lower than the 20d's 800-850.

In my opinion this arrangement gives torque multiplication at start, protects transmission from sudden load while taking a hard start, jerk free operation at low speeds, and the positive drive once locked. The rotating fluid mass, with the stator induced turbulence is likely to consume some power, making this arrangement fractionally less efficient than dual clutches, but lot simpler, and far more efficient than older generation converters which did not lock up or locked only in top. AMT's have dangerous amount of lag, with accidents reported due to them, while DCT's are known for their issues which are reducing by the day as engineers work on them, but they may probably never be totally eliminated.

With smaller diesels being the norm in India. (Even premium cars have comparatively smaller diesels 2~2.2 at most 3 Lit ones) Torque multiplication is needed, and a 6 or more ratio transmission with lock up type torque converter is actually ideal for our conditions.

Note performance difference between a Verna AT & Elantra AT with both P & D. Elantra the slightly heavier sibling but with a 6 speed box whose converter lock operates from as low as 30kph in 3rd upto 6th accelerates better yet returns better fuel efficiency than the Verna with 4 ratios whose converter locks only in 4th and above 70, though both share the same engines.

Rahul

[Lalitha Venkat]

Have a question. Which of the cars sold in India uses the ZF 8 speed TC gear box? I have read, several positive reviews on the gear box performance. Was not happy with the 9 speed box on Jeep Compass and hence wanted to test drive any car which houses the ZF 8 speed TC gear box. If any one can assist here

[androdev]

Originally Posted by GTO

Keeping that in mind, why is ZF bringing out a dual-clutch? Only reason I can think of is an order from a car manufacturer. ZF, after all, is a component manufacturer who'll give car manufacturers whatever they want.

My guess is that ZF 8 can not be accommodated in some platforms like rear-engined Porsche 911.

Originally Posted by Lalitha Venkat

Have a question. Which of the cars sold in India uses the ZF 8 speed TC gear box? I have read, several positive reviews on the gear box performance. Was not happy with the 9 speed box on Jeep Compass and hence wanted to test drive any car which houses the ZF 8 speed TC gear box. If any one can assist here

BMW RWD cars would be your best bet. Many other brands are moving (have moved) to ZF-8, you can find the full list here:
https://en.wikipedia.org/wiki/ZF_8HP...n#Applications

[Dr.AD]

Originally Posted by dZired

ZF Friedrichshafen AG, the famous automotive component manufacturer from Germany, has officially started production of an all-new 8-speed dual-clutch transmission unit.

I think this is a great news. ZF is one of the best in designing fast and reliable gearboxes, and if they design a new dual-clutch transmission, chances are high we will finally see a reliable dual-clutch transmission with all the other goodness of this technology.

I am glad that automobile world is not giving up on dual-clutch technology. Yes, it has been proven consistently unreliable across multiple OEMs. However, I do not see what is fundamentally so wrong there. Maybe it is just the complexity of the system. And the complexity can me conquered over time and over design iterations, and one day we might see a super-reliable dual-clutch transmission. I think this move by ZF-8 is in the right direction.

Originally Posted by GTO

The current 8-speed ZF is the best automatic gearbox out there. It is simply fantastic! The gearbox scores on smoothness, response time and shift speed. Even the manual mode is aggressive. I can't think of a single downside to the current ZF 8-speed.

Totally agree. The current ZF8 is just fantastic and reliable. And that is why I am happy that the the same guys are attempting a new DCT design. But then again, the ZF-9 is not that reliable. Therefore, I am not saying that ZF will always design a reliable gearbox, but I am glad that they are trying.

Keeping that in mind, why is ZF bringing out a dual-clutch? Only reason I can think of is an order from a car manufacturer. ZF, after all, is a component manufacturer who'll give car manufacturers whatever they want.

An OEM order is definitely part of the equation, but more than that, I believe they must have some design improvement in mind. This news clearly mentions investment in a "new" design. They very well know all the failures of the existing DCT transmissions. With all the feedback and the root cause analysis, if they start from scratch and are planning to design a fresh gearbox from scratch, it is most likely that they have figured out some solutions to the reliability woes of DCT. I would love to wait and see how this unfolds.

Originally Posted by androdev

My guess is that ZF 8 can not be accommodated in some platforms like rear-engined Porsche 911.

That could one of the reasons, but is unlikely to be the main reason. If that was the only reason, they could have just redesigned a TC gearbox for the layout suitable for rear-engined cars. This does not necessarily require a switch to DCT (but requires a switch to a different layout). When they are designing a new DCT from scratch, it is likely they have some improvements over existing designs in plan.

Originally Posted by Lalitha Venkat

Have a question. Which of the cars sold in India uses the ZF 8 speed TC gear box?

As @androdev mentioned above, all recent (since 2012 for sure) RWD BMWs in India have this ZF-8. Even Jaguars have ZF-8 in India, but somehow their ZF-8 is not tuned as well as the BMWs. If you want to try the best of the ZF-8 transmissions, try any recent RWD BMW in India.

[Lalitha Venkat]

[quote=Dr.AD;5117543]I think this is a great news. ZF is one of the best in designing fast and reliable gearboxes, and if they design a new dual-clutch transmission, chances are high we will finally see a reliable dual-clutch transmission with all the other goodness of this technology]

I have been using the DSG box of VW for the last 6-7 years on the Vento1.2 TSI. The gearbox and engine combination is very effective and is super smooth and fun to drive. Though, I am not an expert, I feel the combination works well on smaller cc engines. Also there is a specific knack of driving which you can figure out which removes the jerkiness. So if you are using a DCT you need to be tactful. The reason I am articulating this point as many of users have complained on the jerking issues on Seltos which is also DCT. Any DCT will have these issues even if ZF makes them. ZF 9 is not great box and after spending 30 plus lakhs it makes Compass an unimpressive automatic. The cars that use ZF 8 TC auto is above my budget.

[androdev]

DCT is not new to ZF. They supply PDK to Porsche and "components" to companies like Mercedes that make their won gearboxes. PDKs have their fair share of reliability issues and require full replacement even if there is a minor problem. This total lack of repairability makes PDK worse than DSG, so I wouldn't hold my breath for ZF to go mainstream with DCT.

The problem with dual clutch is that manufacturers have to accept DCTs fail a lot more and they mush support cheaper repair options. This "sealed for life", "not serviceable replace-only" approach is really hurting the acceptance of DCT technology. Mechanically DCT is as robust as a manual transmission. Only solenoids and sensors fail, which are very cheap to replace but the manufacturers make it impossible to do such repairs. Instead of replacing a solenoid (of 10$), they expect you to replace the entire valve body (mechatronic) in the case of DSG and entire transmission in the case of PDK. It's like old computers vs new ones where even a failure of SSD requires entire motherboard to be replaced. It's a profitable model to everyone except to the customer.

DCT is a wonderful transmission for enthusiasts. While ZF8 has become super responsive and made many DCTs obsolete, the fundamental mechanical feel of a dual clutch has that unique appeal just like an IC engine vs smooth EV.