NAG1 Automatic Transmission - Service Information: Specifications Dodge Nitro I

Torque Converter Lockup Clutch Regulating Valve

The torque converter lockup clutch regulating valve (6) regulates the torque converter lock-up clutch working pressure (p-TCC) in relation to the torque converter clutch control pressure (p-S/TCC). According to the size of the working pressure (p-A), the torque converter lockup clutch is either Engaged, Disengaged, or Slipping. When the regulating valve (6) is in the lower position, lubricating oil flows through the torque converter and oil cooler (7) into the transmission (torque converter lockup clutch unpressurized). In its regulating position (slipping, torque converter lockup clutch pressurized), a reduced volume of lubricating oil flows through the annular passage bypassing the torque converter and passing direct through the oil cooler into the transmission. The rest of the lubricating oil is directed via the throttle "a" into the torque converter in order to cool the torque converter lockup clutch. see scheme 144

TORQUE CONVERTER LOCKUP CLUTCH PWM SOLENOID VALVE

The torque converter lockup PWM solenoid (1) valve converts pulse-wave-modulated current controlled by the TCM into the appropriate hydraulic control pressure (p-S/TCC). see scheme 253

TORQUE CONVERTER

The converter impeller (driving member) (2), which is integral to the converter housing and bolted to the engine drive plate, rotates at engine speed. The converter turbine (driven member) (1), which reacts from fluid pressure generated by the impeller, rotates and turns the transmission input shaft (4). see scheme 266

TORQUE CONVERTER CLUTCH (TCC)

In a standard torque converter, the impeller (2) and turbine (1) are rotating at about the same speed and the stator (3) is freewheeling, providing no torque multiplication. By applying the turbine's piston and friction material (9), a total converter engagement can be obtained. The result of this engagement is a direct 1:1 mechanical link between the engine and the transmission. see scheme 268

The clutch can be engaged in second, third, fourth, and fifth gear ranges.

The TCM controls the torque converter by way of internal logic software. The programming of the software provides the TCM with control over the torque converter solenoid. There are four output logic states that can be applied as follows

1. No EMCC
2. Partial EMCC
3. Full EMCC
4. Gradual-to-no EMCC

1. Remove transmission and torque converter from vehicle. See «REMOVAL»(ref-306223-S18170500802008120900000) .
2. Place a suitable drain pan under the converter housing end of the transmission. CAUTION: Verify that transmission is secure on the lifting device or work surface, the center of gravity of the transmission will shift when the torque converter is removed creating an unstable condition. The torque converter is a heavy unit. Use caution when separating the torque converter from the transmission.
3. Pull the torque converter forward until the center hub clears the oil pump seal.
4. Separate the torque converter from the transmission.

Scheme 341

Check converter hub and drive flats for sharp edges, burrs, scratches, or nicks. Polish the hub and flats with 320/400 grit paper or crocus cloth if necessary. The hub must be smooth to avoid damaging the pump seal at installation.

1. Lubricate oil pump seal lip with transmission fluid.
2. Place torque converter in position on transmission. CAUTION: Do not damage oil pump seal or converter hub while inserting torque converter into the front of the transmission.
3. Align torque converter to oil pump seal opening.
4. Insert torque converter hub into oil pump.
5. While pushing torque converter inward, rotate converter until converter is fully seated in the oil pump gears.
6. Check converter seating with a scale and straightedge. (Scheme 341) Surface of converter lugs should be at least 19 mm (3/4 in.) to rear of straightedge when converter is fully seated.
7. If necessary, temporarily secure converter with C-clamp attached to the converter housing.
8. Install the transmission in the vehicle.
9. Fill the transmission with the recommended fluid.

TORQUE CONVERTER HUB SEAL

1. Remove the torque converter. See «REMOVAL»(ref-306223-S07978456002008120900000) .
2. Remove the torque converter hub seal with suitable screw and slide hammer.

Scheme 342

Scheme 343

1. Position the torque converter hub seal (1) over the input shaft and against the transmission oil pump. (Scheme 342) 1 - OIL PUMP 2 - SEAL INSTALLER 8902A
2. Using Seal Installer 8902A (2), install a new torque converter hub seal. (Scheme 343)
3. Install the torque converter. See «INSTALLATION»(ref-306223-S34176205472008120900000).

Scheme 344

The automatic transmission is operated with the help of a shift lever assembly (SLA) (1) located in the floor console. There are four positions to which the selection lever can be shifted: P, R, N, D. In addition, the selector lever can be moved sideways (+/-) in position "D" to adjust the shift range. (Scheme 344)

All selector lever positions, as well as selected shift ranges in position "D", are identified by the SLA. The information is then sent to the transmission control module (TCM) via a hardwire connection. At the same time, the selector lever positions "P", "R", "N" and "D" are transmitted by a shift cable to the selector shaft in the transmission.

The SLA is comprised of the following functions

1. Key lock: Depending on the selector lever position, the ignition cylinder is locked/unlocked, i.e, the ignition key can be removed only if the selector lever is in position "P". A park lock cable is used to perform this function.
2. Park lock: The selector lever is not released from postion "P" until the brake pedal has been applied and the ignition key is in "ACC" or ON" positions. Shift lock is controlled by the brake light switch in conjunction with a locking solenoid in the SLA. As soon as the brake pedal is applied firmly, the locking solenoid is energized and retracted to unlock the selector lever. If the selector lever cannot be moved out of position "P" due to a malfunction, the shift lock function can be overriden (2) (Refer to «OPERATION»(ref-306223-S28212956402008120900000) ).
3. Reverse inhibitor: As soon as the vehicle speed exceeds approximately 4-7 mph, it is no longer possible to move the selector lever from position "N" to position "R". The reverse inhibit functionality is controlled by the same solenoid as the park lock. As the vehicle accelerates past the calibrated speed threshold, the solenoid is energized to block the sideways motion of the shift lever necessary to move from NEUTRAL to REVERSE. The reverse inhibit is not released until the vehicle speed falls below approximately 4-7 mph and the shifter is moved out of the "D" shifter position.