Almost 2½ months ago, Kaizen Factor indulged in some of our much-loved Informed Speculation and attempted to delve into the specifics of The BRZ / FR-S / GT 86 transmissions and driveline. No sooner had we posted it, however, that Paul Williamsen, National Manager of Lexus College (this being the brand’s product training division, and an integral part of new model long lead press previews) made the following observations:
…we’re still getting contradictory info out of TMC (Toyota Motor Corporation) on which 6-spd Aisin tranny we’ll have in the FT86, FR-S, & BRZ.
One of the obvious differences between the old IS 200/Altezza box (TMC type J160) and the current IS 250/Cadillac/Porsche box (TMC type RA6X) is that the former has gear reduction on the input side, while the latter has its reduction at the output end. We’ve seen references to both types.
Perhaps, then, things weren’t as clear-cut as they first appeared.
Flash-forward to Wednesday 25 April and the end of the press embargo on the Scion FR-S long lead preview. Although we at Kaizen Factor were not blessed with an invitation, FT-86Club.com‘s stellar coverage was the next best thing to being there. Their correspondent Ichitaka went as far as scanning and posting the Long Lead Press Presentation Outline, in a format familiar to this author from multiple Lexus press previews. Curious over the transmission information contained therein, we were gratified that our prediction of the Lexus IS 250-sourced A960E 6-speed automatic with upgrades such as earlier torque converter lockup, faster upshift and downshift times and throttle blips accompanying downshifts was spot-on. This author did a stunned double-take, however, to see the 6-speed manual identified as an RA62 – just like the less-than-stellar Lexus IS 250 Manual’s transmission – in both the Page 2 index and Page 26, as shown below.
A quick primer on Toyota’s 6-speed manual RWD transmissions
Although our earlier article covered this ground in far greater detail, a recap on Toyota’s 6-speed manual rear-wheel-drive-centric transmissions is in order. In essence, there are only three of them: The Getrag 233 / Toyota V160/V161 used in the legendary Supra Mark IV Twin Turbo; the Aisin AY6 / Toyota/Lexus RA60 series and the Aisin AZ6 / Toyota/Lexus J160. The AY6/RA60 series is, essentially, a beefy truck transmission whose vague shift feel is decidedly subpar for a rear-wheel-drive transmission. Except for RA62 (Lexus IS 250 and, allegedly, Scion FR-S and its derivatives) and RA63 (Europe’s Lexus IS 200d and IS 220d diesels), its other Toyota applications are in Tacoma and FJ Cruiser. The AZ6/J160, on the other hand, is a far more logical basis for the so-called Toyobaru coupe’s manual, having graced not only Toyota Altezza and 1st-generation Lexus IS 200 manual models, but such legendary sports cars as the Honda S2000, Mazda RX-8, 2nd-gen (NB) Mazda MX-5 Miata and the final S15 Nissan Silvia Spec-R. Frankly, we thought that the picture below (from the 2011 Tokyo Motor Show), as featured in our prior article, had settled the issue.
Were we (and Aisin) wrong, then? This skeptical author investigates
Although we’ve never seen such an egregious error in any Toyota/Lexus/Scion press preview printout, this author remained deeply skeptical. Another of the Scion FR-S long lead press materials, the “86″ Development Story brochure delves into the transmission issue on page 14, as shown below. This starts out with by noting that “…transmission development began with an effort to shorten the stroke of the 6-speed manual transmission used in the Altezza…” – an implicit admission that they started out with the Aisin AZ6/Toyota J160 transmission. Beyond that, the story twists and turns, and informs us how engineers from Toyota, Subaru and Aisin AI engineers came together and brought in Takeshi Kaino, a researcher specializing in shift feel to help implement the ideal 6-speed manual transmission. They go on to say that
After creating five different prototypes and executing a final, daring overall design change, the team finally succeeded in creating the ideal 6-speed manual transmission for a sports car…
(Tomohiro) Ishikawa (6-speed manual transmission development director): “Perhaps 80% of the design had changed. More than that, if you look at blueprints for individual parts. Most of the parts were changed I bet.”
No word one way or the other, however, on whether or not at some point they changed from the J160 to the RA62 as a basis for the FR-S / BRZ / GT 86 manual transmission.
Mild skepticism morphed into full-on raging doubt, however, when comparing the Scion FR-S “RA62″ individual gear ratios as shown in the second illustration above to those of the undoubtedly RA62 Lexus IS 250 Manual (as shown in a PDF document linked to the Lexus USA Newsroom’s 2012 Lexus IS 250/350 Product Information page). Except for a direct 1.000 5th-gear ratio, none of the individual gear ratios (not even reverse!) are shared by the two so-called RA62 iterations! And, given past Toyota history, when the slightest changes to an individual gear ratio or two warranted a new transmission denomination (see the RA60, RA60F, RA61, RA62 and RA63 family, or, going further back, the W55, W56, W57, W58, and W59 family of RWD 5-speed manual transmissions, which are externally and internally very similar aside from the gear ratios), we doubt that 2 transmissions that share but one of 7 gear ratios would carry the same code.
Paul Williamsen sets the record straight
Beyond his impressive talents that include Product Engineering, Design, & Development and Curriculum Design & Development, Mr. Williamsen is a walking encyclopedia when it comes to all things Toyota. Thus, he seemed to be a natural source to shed some light on the murky subject of the Scion FR-S / Subaru BRZ / Toyota (GT) 86 manual transmission. And his reply certainly did just that:
Preliminary info from TMC Engineering Div. did not allow us to make a positive identification of origins of the 6-speed manual transmission used in the the FT-86/FR-S/BRZ.
Newer, more thorough, information from TMC identifies the FR-S/BRZ transmission as an all-new type, the TL70.
A technical drawing of the TL70 shows that the order of the gears on the shafts (below) DOES NOT MATCH the RA60: the TL70 does match the sequence of the Aisin AZ6 (TMC type J160) 6-spd manual gearbox fitted to the original Toyota Altezza 2.0 (in Japan) and IS 200 (for Europe).
Similarly, illustrations of the TL70 internal shift linkage indicate that it is more like the J160 than the RA60 series. The ratios are unique to the TL70, with a closer overall spread of ratios than the RA62 of the current IS 250.
I have not been able to personally inspect any of these parts out of the new car and compare them to the earlier models.
There you have it, then. In summary, Toyota, Subaru and Aisin engineers started with the AZ6/J160 manual from the Toyota Altezza/Lexus IS 200, changed at least 80% of it in the quest for improved shift quality and came up with the AZ6-derived TL70 manual that graces the Subaru BRZ and its Toyota-badged stablemates. The only connection to the AY6/RA62 was the one erroneously made by whoever put together the Scion FR-S Long Lead Press Presentation Outline. Thus, we can accurately state that we and Aisin were closest to the truth.