C635 Ddct Automatic Transmission - Service Information: Overview Dodge Dart PF

DESCRIPTION

The C635 DDCT is an electronically controlled and automatically shifted transaxle with a dual clutch torque conversion system is a three-shaft transmission capable of transmitting a maximum torque of 350 Nm. It implements innovative technology for combining the comfortable gear shifts of an automatic transmission with lower running costs, better than that of a manual gearbox. By increasing the transmittable torque capacity (which reaches 350 N.m). The features of the new transmission include the possibility of acquiring a highly sporty connotation by optimizing gear shift times and uninterrupted drive torque delivery to the wheels. The C635 DDCT has a typical three-shaft layout for additional compactness. A particularity is that the main shaft actually consists of two mutually coaxial driveshafts. Two dry clutches, operated by two separate slave cylinders, are used to transmit torque to the main shaft. A traditional concentric slave cylinder located under the gearbox casing to manage the even gear clutch and a second one located on the gearbox casing to manage the odd gear clutch. Gears are engaged and the clutches are managed by an hydraulic power unit, controlled in turn by a specific transmission control module. The hydraulic power unit is positioned directly on the gearbox

1. 6 synchronized gears
2. Three shafts, one input (two piece main) shaft plus counter shafts
3. Main shaft formed by two reciprocally coaxial shafts
4. Double dry clutch
5. Double slave cylinders for the clutches
6. Free wheel for reverse engagement
7. Hydraulic Power Unit for clutch and gear shift control
8. Dedicated TCM

OPERATION

The C635 dual dry clutch transaxle (DDCT) can shift without interrupting torque delivery to the wheels by overlapping the disengagement of one clutch with the engagement of the other. Because the input shafts are split between the odd and even gears, an even gear can be pre-selected while driving in an odd gear. The shift from odd to even only requires the clutches to swap.

Scheme 314

FIRST GEAR POWER FLOW

In 1st gear, engine power is transferred from the odd gear input shaft to the 1st driven gear. The 1-3 synchronizer locks the driven gear to the 1-3-6 output shaft. The output shaft transfers power to the differential which drive the half shafts.

Scheme 315

SECOND GEAR POWER FLOW

In 2nd gear, engine power is transferred from the even gear input shaft to the 2nd driven gear. The 2-4 synchronizer locks the driven gear to the 2-4-5-R output shaft. The output shaft transfers power to the differential which drive the half shafts.

Scheme 316

THIRD GEAR POWER FLOW

In 3rd gear, engine power is transferred from the odd gear input shaft to the 3rd driven gear. The 1-3 synchronizer locks the driven gear to the 1-3-6 output shaft. The output shaft transfers power to the differential which drive the half shafts.

Scheme 317

FOURTH GEAR POWER FLOW

In 4th gear, engine power is transferred from the even gear input shaft to the 4th driven gear. The 2-4 synchronizer locks the driven gear to the 2-4-5-R output shaft. The output shaft transfers power to the differential which drive the half shafts.

Scheme 318

FIFTH GEAR POWER FLOW

In 5th gear, engine power is transferred from the odd gear input shaft to the 5th driven gear. The 5-R synchronizer locks the driven gear to the 2-4-5-R output shaft. The output shaft transfers power to the differential which drive the half shafts.

Scheme 319

SIXTH GEAR POWER FLOW

In 6th gear, engine power is transferred from the even gear input shaft to the 6th driven gear. The 6th gear synchronizer locks the driven gear to the 1-3-6 output shaft. The output shaft transfers power to the differential which drive the half shafts.

Scheme 320

REVERSE GEAR POWER FLOW

In reverse, engine power is transferred from the odd gear input shaft to the reverse idler gear, to the reverse driven gear. The 5-R synchronizer locks the driven gear to the 2-4-5-R output shaft. The output shaft transfers power to the differential which drive the half shafts.

Note. The power cord must be secured in its retainer clips, and not positioned so it could contact linkages or exhaust manifolds and become damaged.

When operating vehicles equipped with the C635 DDCT transaxle in ambient temperatures of -40 degrees C (-40 degrees F) the transaxle / differential heater needs to be engaged for 150 minutes to ensure proper transaxle operation at engine start up. The transaxle / differential heater is mounted into a cavity in the transaxle case near the differential. The heater element is a dry cylinder type design and is powered by 110 volt AC.

Scheme 321

Scheme 322

Scheme 323

1. Raise the vehicle.
2. Remove the belly pan.
3. Disconnect the power cord plug from engine block heater.
4. Disconnect the power cord plug from transmission heater (1).
5. Detach the wiring harness from the transaxle case (2).
6. Remove transmission heater element from the transmission case pulling straight away from the transaxle.
7. Lower the vehicle.
8. Detach the wiring harness from the support brace.
9. Disconnect the block / transmission heater wiring harness at the fender and remove from the vehicle.

SMART DRIVE UNIT (SDU) OPERATION

The SDU is located on the battery enclosure on the driver side of the engine compartment.

The Transmission Control Module (TCM) controls the SDU with a Pulse Width Modulated (PWM) signal. Based on that signal, the SDU varies voltage applied to the electric pump motor, that varies the speed of the motor. The SDU receives battery voltage through a dedicated fuse and does not communicate on any bus. Refer to the Wiring Diagrams for proper circuit and pin information.

Scheme 324

1. Open the hood and support it on the prop-rod.
2. Disconnect the battery negative cable clamp.
3. Release the wire connector lock (3) on the Smart Drive Unit (SDU) (1) connector (2).
4. Separate the connector (2) from the SDU (1).
5. Remove the bolts holding the SDU (1) to the battery enclosure (2).
6. Separate the SDU from the vehicle.