Transmission – Overview

Design and Function

Applies to: 2008–2014; TF-80SC, TF-80SC AWD

TF-80SC (TF-80SC AWD) is an electronically controlled 6-speed automatic transmission with Geartronic.

The Geartronic function combines two transmissions in one. One adaptive 6-gear automatic transmission which enables relaxed driving , and a "manually" shifted transmission which enables more active driving with manual shifting. In case of manual shifting, the gear selector is pushed forward to upshift to a higher gear and it's pulled back to downshift to a lower gear. However, in certain situations the Transmission control module (TCM) assumes the gearshifting decisions. For more information about shifting with Geartronic, see Design and Function, Transmission control module (TCM).

TF-80SC has a lock-up-function on all forward gears except 1st gear. The torque converter has a locked and slipping lock-up-function.

Gearshifts are controlled by an hydraulic operating system. Gearshifts take place without freewheeling and completely automatically in terms of load and speed.

TF-80SC has two planetary train units, a front and a rear, whose shifts are controlled by a number of clutches and brakes. The rear planetary train is of the Ravigneaux type.

The oil level is checked by level pipe (the transmission does not have a conventional dipstick).

The transmission has a total of 8 solenoids that control the hydraulic flow. 6 of these solenoids control the shift process, 1 solenoid controls the torque converter's lock-up function and 1 solenoid controls the system pressure.

The gear selector sensor is integrated in the Transmission control module (TCM). The Transmission control module (TCM) is integrated in the transmission. For information about the Transmission control module (TCM), solenoids and sensors, see Design and function, Transmission control module (TCM).

Applies to: 2010–2013; MPS6

This Design and Function describes the transmission's mechanical parts.

The transmission is a 6-speed electronically controlled transmission, so-called Powershift. It has the same function as an automatic transmission but is more similar to a manual transmission.

The transmission is of a design with three shafts and two clutches (wet double clutch) but no clutch pedal. Electronics and hydraulics control the clutches just like in a conventional automatic transmission.

The transmission features a split (divided) input shaft with a clutch each. The clutches work independently of each other.

The transmission has 4 gearshift forks which are controlled by the Transmission control module (TCM) via solenoids. Electronics and hydraulics control the clutches via the Transmission control module (TCM) or via manual shifting in the same way as in a conventional automatic transmission. In case of manual shifting, the driver handles gearshifting.

The gears are pre-selected, that is, one clutch makes sures that the current gear ends up in the correct position at the same time as the other clutch prepares the next gear. This set-up means that the power transfer from the engine to the transmission is not interrupted when shifting.

Shifting takes place under load, thus a permanent power transfer can be maintained, which is the meaning of Powershift.

The gearshift lever is of the same type as for conventional automatic transmissions and has positions P, R, N, D, and M.

The transmission fluid is a high-quality synthetic oil which is unique for this type of transmission. For transmission oil change interval, see Service program.

The transmission is intended to be a part of a transverse drivetrain with front-wheel drive. The transmission weighs 91 kg with oil and has a maximum torque of 450 Nm.

The Transmission control module (TCM), solenoids, and sensors are integrated in the transmission. For more information on Transmission control module (TCM), its function and associated sensors, see Design and Function, Transmission control module (TCM).

Applies to: 2011–2014; TF-80SC AWD

Automatic transmission TF80SC Generation 2

This transmission has been updated on several points to meet high demands for fuel economy and comfort. TF80SC Gen 2 replaces earlier versions of TF80SC.

Changes compared to earlier version:

• Solenoids
• tapered bearings
• friction pads
• Seals
• oil with lower viscosity
• "lock-up" at lower engine rpm
• software in TCM (Transmission Control Module)
• fastening AC bracket (6-cyl. engines)

These changes contribute to lower internal losses and, together with upshifting at lower engine rpms, faster downshifts, the result is lower fuel consumption, better shifting quality, and higher efficiency.

TF-80SC (TF-80SC AWD) is an electronically controlled 6-speed automatic transmission with Geartronic.

The Geartronic function combines two transmissions in one. One adaptive 6-gear automatic transmission which enables relaxed driving, and a "manually" shifted transmission which enables more active driving with manual shifting. In case of manual shifting, the gear selector is pushed forward to upshift to a higher gear and it's pulled back to downshift to a lower gear. However, in certain situations the Transmission control module (TCM) assumes the gearshifting decisions. For more information about shifting with Geartronic, see Design and Function, Transmission control module (TCM).

TF-80SC has a lock-up-function on all forward gears except 1st gear. The torque converter has a locked and slipping lock-up-function.

Gearshifts are controlled by an hydraulic operating system. Gearshifts take place without freewheeling and completely automatically in terms of load and speed.

TF-80SC has two planetary train units, a front and a rear, whose shifts are controlled by a number of clutches and brakes. The rear planetary train is of the Ravigneaux type.

The oil level is checked by level pipe (the transmission does not have a conventional dipstick).

The transmission has a total of 8 solenoids that control the hydraulic flow. 6 of these solenoids control the shift process, 1 solenoid controls the torque converter's lock-up function and 1 solenoid controls the system pressure.

The gear selector sensor is integrated in the Transmission control module (TCM). The Transmission control module (TCM) is integrated in the transmission. For information about the Transmission control module (TCM), solenoids and sensors, see Design and function, Transmission control module (TCM).

Applies to: 2012–2016; TF-80SD

Transmission TF-80SD

TF-80SD is an electronically controlled 6-speed automatic gearbox with Geartronic.

The Geartronic function combines two transmissions in one. One adaptive 6-gear automatic transmission which enables relaxed driving, and a "manually" shifted transmission which enables more active driving with manual shifting. In case of manual shifting, the gear selector is pushed forward to upshift to a higher gear and it's pulled back to downshift to a lower gear. However, in certain situations the Transmission control module (TCM) assumes the gearshifting decisions. For more information about shifting with Geartronic, see Design and Function, Transmission control module (TCM).

TF-80SD has a lock-up-function on all forward gears except 1st gear. The torque converter has a locked and slipping lock-up-function.

Gearshifts are controlled by an hydraulic operating system. Gearshifts take place without freewheeling and completely automatically in terms of load and speed.

TF-80SD has two planetary train units, a front and a rear, whose shifts are controlled by a number of clutches and brakes. The rear planetary train is of the Ravigneaux type.

The oil level is checked by level pipe (the transmission does not have a conventional dipstick).

The transmission has a total of 8 solenoids that control the hydraulic flow. 6 of these solenoids control the shift process, 1 solenoid controls the torque converter's lock-up function and 1 solenoid controls the system pressure.

The gear selector sensor is integrated in the Transmission control module (TCM). The Transmission control module (TCM) is integrated in the transmission. For information about the Transmission control module (TCM), solenoids and sensors, see Design and function, Transmission control module (TCM).

An electric oil pump is located on the converter cover beside the control system on the front edge of the transmission. The oil pump function is to ensure that the correct pressure and flow are maintained to the gearbox during automatic start/stop which is controlled by the transmission control module (TCM). In the event of a fault in the oil pump the automatic start/stop function stops.