Subaru motor vehicles have used manual, conventional automatic, and continuously variable (CVT) transmissions. Subaru manufactures their own manual transmissions. Lately, all Subaru automatic transmissions have been Jatco designs adapted to Subaru specifications.
Contents |
All of Subaru's three speed automatic transmissions were made by JATCO.
The 3EAT was an electronically controlled 3AT with available Single-Range 4WD.
Subaru built their own four speed automatic transmission based on the old Jatco design. It was available in FWD and Full-Time AWD form.
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, 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. Active Torque Split and VTD are utilized on transmissions with at least 4 gears, or the 4EAT and 5EAT.
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. Also, this transmission is a four speed automatic with a lock-up torque converter, not a 3 speed automatic with automatic overdrive.
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.
Subaru released the 5EAT w/ SportShift in 2003 based on the Jatco JR507E transmission.
1st 3.080 2nd 2.264 3rd 1.471 4th 1.000 5th 0.834 Rev 3.372
Subaru made a one off paddle-shift AWD transmission for their B11S Concept car built off of the 5EAT platform.
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 Park-Reverse-Neutral-Drive Normal-Drive Sport. Regrettably, 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 fifth generation Legacy/Outback and the JDM Subaru Exiga received a newly-revised CVT under the Lineartronic name. It is a metal-belted, pulley-based CVT, which is considered the most reliable, due to the simplicity of the pulley system and durability of the metal belt. In addition, the metal belted pulley system is generally quieter than other CVT designs. In the US, the Lineartronic is available only with the 2.5i engine in both the Outback and Legacy. 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 has a conventional torque converter in place of a clutch [2][3]. The transmission can also be manually controlled by the driver by providing the ability to select 6 different "virtual" gears, where the transmission will hold a particular ratio.
Subaru made several four speed transmissions from 1970–1989, they are listed below.
1st 3.636 2nd 1.950 3rd 1.344 4th .971 5th .783, Rev 3.583
This was the only five-speed 4WD transmission made for the Subaru Leone
This transmission was Subaru's first Full-Time 4WD transmission, only used in the Alcyone/XT6.
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.
The Justy's transaxle was modified to fit push-button 4WD in 1988. The gear ratios were also altered slightly.
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
There are three six speed manual transmissions currently available for USDM Subarus. The STi and Legacy Spec B are the two vehicles that received them. The STi's 6MT has undergone various changes throughout the years, but have always had a limited slip front differential and the 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.
The new 2010 Legacy and Outback models will 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.