List of Subaru transmissions

Subaru motor vehicles have used manual, conventional automatic, and continuously variable (CVT) transmissions. Subaru manufactures its own manual and CVT transmissions (for non-Kei cars). Since the 1970s, all Subaru conventional automatic transmissions have been Jatco designs adapted to Subaru specifications. Since the 2014 model year, the conventional automatic transmissions in North American-spec Subaru vehicles have been replaced with Lineartronic CVTs.


Automatic

Three-speed

All of Subaru's three speed automatic transmissions were made by Jatco.

3AT

3AT 1st revision

3EAT

The 3EAT was an electronically controlled 3AT with available Single-Range 4WD.

Four-speed

Subaru built their own four-speed automatic transmission based on the old Jatco design. It was available in FWD and Full-time awd.

ACT-4 or VTD

Subaru uses two types of traction delivery systems, called Active Torque Split, or the performance oriented Variable Torque Distribution, called VTD. Active Torque Split has a front axle bias of 60:40 (90:10 in 1993-2009 4EAT Legacys/Libertys), and sends torque to the rear wheels when front traction loss is detected. The first system is the more commonly used setup used on most Subaru products. VTD has more of a rear axle bias varying in deployment ratios of 45:55. VTD is usually found in performance models equipped with a turbocharger and VDC models. Active Torque Split and VTD are utilized on transmissions with at least 4 gears, or the 4EAT and 5EAT.

4EAT

This transmission was released in 1988 for use in the Subaru XT6 and Leone Touring Wagon. The bellhousing and input shaft were changed for the Subaru EJ engine, but this transmission is still in use today with only minor changes.

The Ford Motor Company also uses a transmission on some Ford, Kia Motors, Mercury, and Mazda products called the F-4EAT, which shares some similarities with the Subaru, since they are both manufactured by Jatco. The Nissan Pathfinder has also used this transmission in the past with an external transfer case attached.

Five-speed

Subaru released the 5EAT w/ SportShift in 2003 based on the Jatco JR507E transmission.

5EAT

1st 3.540 2nd 2.264 3rd 1.471 4th 1.000 5th 0.834 Rev 2.370

Six-speed

Subaru made a one off paddle-shift AWD transmission for their B11S Concept car built off of the 5EAT platform.

6EATT

Continuously variable

1989–1994 Subaru Justy ECVT/Justy 4WD ECVT

Subaru developed a CVT for the Subaru Justy to gain reasonable acceleration and fuel economy from its small three cylinder engine. It employs a push-belt system and comes with an optional 4WD unit that engages the rear wheels when a button on the shifter is depressed. It also has a 'sport mode' that when activated nearly doubles engine RPM for better torque distribution when towing or going uphill. The Shift Indicator reads P-R-N-D-Ds, Ds stands for Drive Sport, which doubles engine RPM. The CVT transmission proved unreliable after accumulating high mileage, causing Subaru to stop exporting cars with CVTs to North America until the fifth generation Legacy/Outback. Subaru did continue to build Kei cars with CVTs, only for sale in Japan. In addition to improving the design of the transmission over the years, Subaru also supplies other companies with CVTs, as well. The Justy ECVT was also available with hydraulically actuated 4WD (unlike the 5sp manual Justy, which has pneumatic actuation) in November 1988, this model was called the Justy 4WD ECVT.

Subaru Lineartronic CVT

Lineartronic CVT transmission

The fifth generation Legacy/Outback and the JDM Subaru Exiga received a newly revised CVT under the Lineartronic name. It is a metal chain, pulley-based CVT, which is considered the most reliable, due to the simplicity of the pulley system and durability of the metal chain. In addition, the metal chain pulley system is generally quieter than other CVT designs. In the US, the Lineartronic is available with the 2.5i engine in the Outback, Legacy and Forester(2014), and the 2.0 FB engine in the Impreza and slightly modified for the XV Crosstrek. In SE Asia this transmission is also available for the 2.0i engine for the 2010 and later Legacy Legacy Asia spec. Subaru claims that the transmission provides "uninterrupted power that maximizes fuel efficiency while keeping the engine at the optimal rev range". EPA mileage estimates for the CVT with the 2.5i, naturally aspirated based engine, claim 30 MPG highway (29 Outback, 31 Legacy).[1] Lineartronic uses a specially modified torque converter to connect the engine to the transmission. It can slip like a traditional torque converter, but remains locked under all conditions except when coasting or traveling at very low speed. The persistent lockup condition under acceleration provides the efficiency and control of a clutch while still behaving much like a traditional planetary automatic transmission. The transmission can also be manually controlled by the driver by providing the ability to select 6 or 7 (if paired with a Diesel engine[2]) different "virtual" gears, where the transmission will hold a particular ratio.

Manual

Four-speed

Subaru made several four speed transmissions from 1970–1989, they are listed below.

T71

T71A 1st revision

T71W 4WD

T71W 4WD 1st revision

T81W 4WD

T81W 4WD 1st revision

Five-speed

T71G

T71G

T81G

5MT EA

1st 3.636 2nd 1.950 3rd 1.344 4th .971 5th .783, Rev 3.583

5MT

This was the only five-speed 4WD transmission made for the Subaru Leone

5MT full-time

This transmission was Subaru's first full-time 4WD transmission, only used in the Alcyone/XT6 and 3 door RX.

5MT Justy

The Justy used a transaxle, rather than a conventional Subaru transmission. This transmission was dropped in 1994 when you could only get a 4WD unit.

5MT Justy 4WD

After its introduction in 1984, the Justy was also available with 4WD and thus a different gearbox. The gear ratios for this gearbox were altered slightly. In 1994 the normal/FWD gearbox was dropped; one could only get a 4WD gearbox by then.

5MT

It is notable to mention that only Turbo vehicles received a hydraulic clutch until 1995. Also, in 1998 Subaru changed from a push-style clutch to a pull-style requiring minor bellhousing and fork changes.

MY 96 Transmission specs (and possibly other years)

Source: 1996 Subaru Legacy Service Manual

Also matches 1999 Legacy 30th Anniversary[3][4]

5MT revised


5MT revised 2012+


5MT turbo

Per my Subaru Service Manual, page 5MT-2, for 2005 Turbo Baja 1st through 5th gear ratios are: 3.454, 1.947, 1.366, 0.972, 0.738 with a final drive ratio of 4.444. The gear ratios for reverse are not provided. Gear ratios for the non-turbo Baja Sport are 3.454, 2.062, 1.488, 1.088, 0.871 with a final drive ratio of 4.111 which agree with those listed on the current web page.

Six-speed

Impreza WRX STi and Legacy spec. B

There are several six speed manual transmissions currently available for USDM Subarus, found in the STi, Legacy Spec B, and 2015 WRX. The STi's 6MT has undergone various changes throughout the years, but have always had a limited slip front differential with Driver Controlled Center Differential (DCCD). In 2006, The STi's 6MT underwent some changes that included making the center differential a limited slip unit and a slight lengthening of some gears. The Spec. B's 6MT has different gear ratios (specifically 6th gear being longer) than the STi's unit, does not have DCCD, and neither the front nor center differentials are limited slip units. The Spec B's 6MT is still highly prized; however, because of its longer ratios than those found in the STi, while still retaining much of the STi unit's robustness.

Model 1st 2nd 3rd 4th 5th 6th Reverse Final Drive DCCD Front Diff Center Diff
US Impreza WRX STi MY04 TY856WH3MA 3,636 2,375 1,761 1,346 0,971 0,756 3,545 3,900 35/65 A.P. Suretrac automatic DCCD system
US Impreza WRX STi MY04 late TY856WH4MA 3,636 2,375 1,761 1,346 0,971 0,756 3,545 3,900 35/65 A.P. Suretrac automatic DCCD system
US Impreza WRX STi MY05 TY856WW6MA 3,636 2,375 1,761 1,346 0,971 0,756 3,545 3,900 35/65 Helical LSD automatic DCCD system

2010 Legacy/Outback

The new 2010 Legacy and Outback models offer a six-speed manual as one of the two transmission options in the base 2.5i, and is the only option for the Legacy GT model. This transmission is an evolution of the 5MT split-case design, and does not share any parts of construction with the STI's 6MT transmission. The transmission uses a cable shifter, unlike all previous designs that use a direct mechanical linkage.

2015 WRX

The 2015 WRX has a new 6-speed cable-shifted manual transmission behind the new FA20DIT boxer engine. This transmission uses a viscous limited slip center differential with a 50/50 torque split similar to the 5MT found in previous WRX's. Reverse is located to the right of 6th gear, and is accessed by lifting a lockout ring below the shift knob, similar to the STi 6MT.

Gear Ratios are: 1st: 3.454 2nd: 1.947 3rd: 1.296 4th: 0.972 5th: 0.780 6th: 0.666 Reverse: 3.636 Final Drive: 4.11

Notes

  1. ↑ http://www.subaru.com/engineering/transmission.html
  2. ↑ http://sgws.subaru.no/2015_outback_spesifikasjon.html?ref=1453239236.122
  3. ↑ "Subaru Transmission Chart" (PDF).
  4. ↑ "Relative measurement of 1999 Legacy Gear Ratios".

Sources

See also

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