Talk:Automatic transmission

It might be worth working up something about Constantinesco's non-hydraulic torque converter of the 1920s. Unfortunately I don't have a link at the moment, but I seem to recall altavista finds it easier than google for some reason. PML.

I'm also pretty sure that some work with hydraulic torque converters began much earlier than the 50s. --Morven 06:48, 7 Oct 2003 (UTC)

Googling for "Constantinesco torque converter" seems to find a few references. --Morven 06:50, 7 Oct 2003 (UTC)

I think the place to look might be [1] - "fluid" because he also looked into power transmission in fluids by means of energy pulses. PML

Gear selection / Shifter

This was completed on January 5 2007 KG

It would be useful to include a section on the shifter mechanism found in automobiles with an automatic transmission. This comes to mind as I work on D (disambiguation) and encounter "D for Drive". I know of three main types: push-button, floor shifter (illustrated in this article) and steering column shifter. Questions that come to mind are a) are there any other styles? and b) is "D for Drive" the same across all languages, or might it be (looking at Wiktionary) "F for Fahren" in German or "V for Vehar" in Ido (though I'd be verrry surprised to see a gear selector encoded for Ido :) ). Thanks for thinking on this and perhaps editing it in. Regards, Courtland 02:13, 29 September 2005 (UTC)

I think the symbols for the transmissions have been standardized, so every carmaker is allowed to use the same letters in the same order. On another note, the BMW and Mercedes's shifter "stalk" is worth mentioning as well. 220.133.92.72 (talk) 20:04, 1 September 2008 (UTC)

Some cars, e.g., the early (1961) Pontiac Tempest, had the transmission selector on the dashboard, next to the ignition switch and radio (IIRC). There were only four choices: R, N, D, and L (i.e., no P). 71.131.218.173 01:04, 20 July 2006 (UTC)

The gear Automatic Transmission Modes section was very confusing, and really could stand to be reformatted. Vendor specific information really should be below general information, for example the information about Honda and Acura models appears ABOVE the more traditional idicators in generic form. I've moved the section about vender specific modes to the bottom, and made minor changes to the overdrive, drive, and "2" entries for clarification. Jo7hs2 03:20, 28 October 2007 (UTC)

Honda Automatic

Did you know that all Honda automatics are actually hydraulically operated manual transmissions with torque convertors in place of the clutch? The transmissions of the Chapparral race cars of the 1960's, such as the famous Chapparral 2J 'Fan Car', were similar as they used a torque convertor instead of a clutch, however the synchro-less 4-speed gearbox was manually shifted.

I find this incredibly doubtful, to say the least. While I'm not certain on the operations of the Chaparral gearboxes (I've heard that they were everything from simply a built-up manual valvebody TH400 to being a dog-box with a torque converter), the idea that Honda automatics are really hydraulically operated manuals (instead of planetary-gear / clutch-pack equipped automatics) is far-fetched at best. Hydraulically operated manuals have not even been in racing use for a terribly long time, and only a handful of cars on the street use them (any Ferrari with the 'F1' designation, or the recent BMWs with the SMG transmission) as their cost is very high compared to a normal automatic. Ayocee 14:57, 6 February 2006 (UTC)

I once possessed one of those Honda Civic semi-automatic transmission called Honda-Matic. Mine had 3 speed, 1st, 2nd, and O/D gear, alongside standard automatic transmission gear selection (P, R, N). Earlier models had only the 1st and 2nd gear. And you cannot compare Ferrari and recent BMW's to earlier cheapier Honda Civic transmissions, that's not hte same technology, and performance. Honda semi-automatic still fonction with planetary gearbox (being manually controlled doesn't mean that it should be built like a manual transmission), only that it is the driver that controls bands and clutches to achieve gear change. They should not cost more than a regular automatic transmission, and at the best they are maybe easier to build. In place on the throttle valve cable, it is the shift cable that changes gears and actuate the bands and clutches to achieve that.Warhammer38m 04:58, 28 April 2007 (UTC)

Japanese "Kei" Cars

Some Japanese "kei" cars (yellow license plate, with a 650cc engine for reduced tax) have a bizarre combination auto gear box. Two fixed ratio low gears, and then a CVT gear above for regular driving. Confirmed in the Suzuki WagonR, and Daihatsu Move, and not in the Subaru Vivio. Unfortunately, I don't know enough about how they work to put an entry in the article, and it'll be difficult to find an english speaking engineer to explain. Given how underpowered these engines are (I estimate under 50bhp), it's probably an attempt to eke out a little more power, and it certaintly seems to help for going up mountains.

PSA AL-4

There is no mention of the AL-4 gear, in the models list. This gear is used by all/many of the recent models of French cars Peugeot, Renault, Citroen . Can you add a link to it, and a list of cars where it is used. It has had many reliability problems. —The preceding unsigned comment was added by 89.0.228.55 (talk • contribs) .

Were not Mercedes (rather than BMW) the first to offer a five speed automatic transmission? If I remember correctly it was available in their 1989 SL?

Failure causes?

What are the actual failure modes for an automotive tranny? For example, a worn/slipping clutch plate will cause the torque converter to not couple properly, leading to power loss at hill climbing and/or highway speeds. This leads to the build up a lot of turbulence in the torque converter, which results in a lot of heat being dumped into the tranny. Now, every consumer brochure states that heat kills trannies, but how is it doing this? Is the high heat warping the valve body or something? Are some bearings getting blown out because hot tranny fluid can't protect them any longer ?  ??? linas 17:48, 22 May 2007 (UTC)

On steering wheel

By the way, what do you call a gearshift on the steering pad, instead of off of it. --PJ Pete

Marketing lingo right now seems to label them as "paddle shifters" when they are on the sides of the steering wheel. The handful of vehicles (mostly modified cars) that have shift mechanisms directly IN the steering wheel are generally just called shift buttons, or something like that. If my assumption that "steering pad" means the surface of the steering wheel... Jo7hs2 03:23, 28 October 2007 (UTC)

Foot brake

The article sais: "In some cars (notably those sold in the US), the driver must have the footbrake depressed before the transmission can be taken out of park." Shouldn't it say pressed?Alessandro Malfatti (talk) 00:44, 7 May 2008 (UTC)

No. "Depress" doesn't mean "don't press" but rather "push or pull (something) down into a lower position : depress the lever" -- or in this case, the pedal. --Fletcher (talk) 00:58, 7 May 2008 (UTC)

To avoid that ambiguity, I'm going to change it to "applied".

Atlant (talk) 16:16, 7 May 2008 (UTC)

I don't think there is any ambiguity -- it is a common English word -- but I'm not going to object.--Fletcher (talk) 16:59, 7 May 2008 (UTC)

Depressed

The problem with "depress" and "depressed" is that the word has an unrelated meaning suffering from extreme sadness, a form of mental illness. 76.21.8.213 (talk) 02:08, 18 June 2008 (UTC)

Don't be silly. Fletcher (talk) 02:23, 18 June 2008 (UTC)

{{copyedit}} tag

Can you please explain what exactly still needs copyediting? I don't really see it. Arienh4^(Talk) 12:58, 12 June 2008 (UTC)

The edit summary that I gave when I added the tag attempts to give a clue.[2] There are many unnecessary parenthetical remarks (poor and/or lazy style) and an amazing plethora of this/that pairs joined with a slash, which is also very bad style. I started to edit the article, but I do not have enough technical knowledge of the subject to know how to properly interpret and convey the subject matter. That in itself is indicative that the article is somehow lacking. If it was very well written, I should come away with a fuller understanding than I do currently.

There are limited legitimate uses for parentheses in well composed prose, and joining terms with a slash is simply not necessary in good writing.

An example:

In order to select gears/modes the driver must push a button in (called the shift lock button) or pull the handle (only on column mounted shifters) out.

Ugh! For starters, I do not know in this technical context whether gears and modes are the same thing or different but related things. That's not my fault, rather it is an example of the article failing to explain itself clearly and fully. Neither of those two parenthetical remarks are needed, and certainly not both in one poor overloaded sentence. Either leave them out completely as not necessary to understanding the core concepts, or rewrite the whole bit, perhaps as multiple sentences. That's just one example. The article is full of similar writing defects.

I understand that often deep understanding of a technical subject and excellent writing skills are disjoint. I see it all the time in the technical field that I work in. It's not a case of being a grease-covered gear-head who just squeaked by in English composition. Because the writer has such a deep and detailed knowledge of the subject it can be very challenging to organize and present that knowledge properly, even if he has good writing skills. Choosing what details to include and what to omit, for example, can be very difficult. But it's important to omit much because the subject would otherwise fill a textbook. What remains is a can be difficult to present clearly to a reader not already steeped in the subject.

I briefly looked to see if there was a different tag that suggests more accurately what kind of attention the article needs, but I didn't see one. And, yes, my parenthetical remarks and slashed/stroked terms here are intentionally poking a little bit of fun at my pedantry on the subject. ;) --Kbh3^rdtalk 16:35, 13 June 2008 (UTC)

How it works...?

In the article, is there actually a section on how the automatic transmission actually works? Or is the link at the bottom to HowStuffWorks the closest it gets? Nonagonal Spider (talk) 07:30, 29 August 2008 (UTC)

Please explain the Bang mode

I don't understandand the following. Is it a bad english, bad joke or is it me? Thanks

Bang (B or I)- This allows the car to unlock and turn the sensors on some cars to allow if the drive is not engaging properly. This is used for cars that have to be careful from speeding alot of times. This is used only for the summer and fall.