Talk:Aisin–Toyota 8-speed automatic transmission

This article should not have been combined

This article was previously a specific piece about the AWF8 transmission used in front wheel drive transverse engine vehicles. It is used in various vehicles from Toyota, Lexus, VW, PSA, etc. and is completely unrelated to the Toyota AA80 transmission. For some reason a user who seems to like merging articles, merged these two totally unrelated transmissions under this one heading of “Toyota Aisin 8-speed transmission” and it includes a blurb that reads “Aisin and Toyota offer a well-developed 8-speed automatic transmissions family.”

There’s already a separate wiki page titled Toyota A transmission that includes information about the longitudinal FR 8-speed transmission (AA8xx).

In my opinion the user that has combined the two transmission types into this one article has created a confusing and misleading wiki page. There’s also various misspellings and grammatical errors. The page as it appears now makes it appear that the AW8F transmission is related to the AA8xx transmission. It is not. It includes a list of various transmissions including the ZF 8HP and other longitudinal transmissions that it says this FF transverse transaxle is related to that is incorrect. I’m not sure how to best undo this series of edits to revert the page back to how it was. I tried to undo the edit to see if it would separate the page into its original separate constituents but it didn’t, so I undid my undo edit.

Merging these disparate transmissions into one article would be akin to putting the 8-speed Porsche PDK transmission manufactured by ZF and the ZF 8HP transmission in one article because both have 8-speeds and are produced by the same company. It would be confusing and make no sense to merge them since they are completely unrelated transmission families.

TurboChargedChiliPepper (talk) 17:10, 1 November 2024 (UTC)

Thank you for your contribution. It is incorrect in its entirety.

(1)

No articles were merged or combined.

(2)

The counterpart to the Toyota A transmission article is the Toyota U transmission article. Both existed before my edits to this article and both continue to exist after my edits to this article. Nothing has been merged.

(3)

The original AW F8 F35 article is a completely different one and has therefore nothing to do with the two above mentioned articles. It described a single transmission model. Wikipedia is not a marketing platform. Articles about products are therefore not permitted. However, articles about technical concepts or economic history are.

(4)

Aisin and Toyota hold patents on a common 8-speed transmission concept that is used by Aisin and Toyota for all their 8-speed automatic transmissions for passenger cars.

(5)

This is an article about a technical concept. This gearset concept is identical for both transmission families. Accordingly, both transmission families are included in this article. This is indicated by the crystal-clear division of both tables (the key data table on top and the comprehensive data table with assessment) into two sections, one for longitudinal and one for transverse installation.

(6)

In this respect, this article represents a cross-section of the two articles mentioned under (2) (actually, the two articles mentioned under (2) are the cross-sectional articles, but that is just a matter of perspective).

(7)

Proof 1: Schematic diagram of gearset concept for longitudinal installation

Figure 2 on page 4 of 10 of the paper you may find here: https://typeset.io/pdf/toyota-aa80e-8-speed-automatic-transmission-with-novel-1hinr9yagl.pdf

Please refer to Footnote 1 of this Wikipedia article ("Toyota AA80E 8-Speed Automatic Transmission with Novel Powertrain Control System · For Longitudinal Engines Only" (PDF))

(8)

Proof 2: Schematic diagram of gearset concept for transverse installation (mirrored version of the schematic for longitudinal installation)

Figure 1 on page 2 of 17 ("sheet 1" of "sheet 6") of the paper you may find here: https://patentimages.storage.googleapis.com/5d/39/34/ec9b8abbc96f30/US8453818.pdf

Please refer to footnote 2 of this Wikipedia article ("Automatic Transmission · US-Patent No. 8,453,818 B2 · For Transverse Engines Only" (PDF))

Translated with DeepL.com (free version) Musikgeniesser (talk) 11:39, 3 November 2024 (UTC)

R2 Reverse Gears

I work with AE80 and AA80 family of transmissions regularly, and while I agree there's a physical possibility that the clutch arrangement will allow a second gear ratio, neither my own testing nor Toyota's documentation indicates that this family of transmissions actually will shift to R2. So respectfully, while it's interesting to note the possibility, I think it's possibly misleading to list a gear the transmission can't achieve, both here and on the Toyota A transmission page. To date, I am aware of only two planetary automatic transmissions with functional reverse gears: Mercedes 5G and Mercedes 7G series.

I'd like to offer a modification to the discussion about the front gearset which I believe should be referred to as a double pinion planetary. The discussion also mentions of the sun gear rotating, but in fact, the sun gear is held stationary to the all of the time in this power flow configuration. Only the planet carrier, driven by the input shaft, and ring gear are able to rotate.

I feel it is also worth mentioning that the rear planet set is not really a standard Ravigneux (with a common planet carrier holding two different sized planet gears meshing with one or two ring gears and two different sun gears). Rather, this gearset features a double pinion planetary with each planet gear meshing with a different sun gear, allowing for both a ratio change and direction change, while only the outer planet is meshing with the ring gear. Guy.Cardwell (talk) 20:32, 3 November 2024 (UTC)

Thank you for your contribution. I did the 5G-Tronic and the 7G-Tronic as well. As the 7G-tronic logic provides a suppressed R3 (!) I grayed R2 here like I did it for R3 there.

(1) R2

I totally agree so I shaded the R2 gray and added some footnotes and changed the chapter in question. As Wikipedia isn't a marketing platform the article is about the patented gearset concept as well and therefore to reflect R2 is a must for a Wikipedia article. I tried to incorporate both. Please be informed, that Toyota gives the ratio for R2 instead of R1 trice (as far as I know):

(a) url=https://typeset.io/pdf/toyota-aa80e-8-speed-automatic-transmission-with-novel-1hinr9yagl.pdf

(b) url=https://media.lexus.co.uk/wp-content/uploads/sites/3/2021/06/1502794419170814MLEXUSGSFTECHNICALSPECIFICATIONS.pdf

(c) url=https://media.lexus.co.uk/wp-content/uploads/sites/3/pdf/211012M-RC-F-Tech-Spec.pdf

To prevent confusion I tried to incorporate this.

(2) Gearset 1

Wikipedia calls reversed epicyclic gearing in its article "[epicyclic gearing]] reversed, so I stuck to this designation. I am german so I hope it is correct. In german I would call it invertiert = inverted. But I don't know what the exact terminus technicus is in english. Please feel free and let me know. Thx in advance.

(3) Ravigneaux

To me the compound gearsets 2 + 3 look like a Ravigneaux gearset. As there are many versions -- with or w/o the small ring gear and so on -- I would like to stick to the designation Ravigneaux. What do you think?

(4) Other articles

I'm open to changes of the articles [Toyota A transmission]] and Toyota U transmission. Musikgeniesser (talk) 00:01, 4 November 2024 (UTC)

Thank you for the edits. Comments follow:

1) I'm familiar with the Toyota scientific paper that launched this transmission family, but I have access to more recent Toyota sources that disagree. One public one of the RC-F transmission is clearly different from the Lexus media USL: https://www.caranddriver.com/lexus/rc-f/specs.

2) Regarding the terminology, please see this: https://www.mathworks.com/help/sdl/ref/doublepinionplanetarygear.html. which is also likely also available in your native German. As MathWorks products are well aligned with the scientific / academic community, I might trust their nomenclature more. Minor point, in any case, and I'm not strident about this.

3) "modified Ravigneuax" might be a better phrase.

4) My only suggestion is that these pages not quote an R2 ratio unless it's been confirmed that these exist as functional gears. Guy.Cardwell (talk) 18:49, 4 November 2024 (UTC)

I have, from time to time, had access to Toyota New Car Features (NCF) documentation which is only available under a paid subscription or from within Toyota. As that material is copyrighted, it can't be reproduced here. The rest of my experience is developing a control system for this family of transmissions. Guy.Cardwell (talk) 20:02, 4 November 2024 (UTC)

Edit: I did the gray fonts plus footnote in both articles, i. e. Toyota A transmission and Toyota U transmission. I hope it's ok for you.