Jeep WK2 Grand Cherokee Transmission

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W5A580 transmission options

(Standard on Laredo, N/A on Limited or Overland, Standard on SRT8)

 

The W5A580 debuted in 1995 Mercedes-Benz passenger autos and is thought to be one of many smoothest, most fuel-efficient and cost-effective transmissions within the business. Its distinctive three-channel torque converter helps present an exceptionally clean journey and shifting, whereas lowering gas consumption. A $455 million improve venture on the Indiana Transmission Plant was began in 2001 and accomplished in 2003. The 600,000 SF plant was designed to provide round 400,000 of the W5A580 transmissions per 12 months for the North American market. The transmission venture was the primary joint effort between the corporate’s American and German wings after the Chrysler Corp. and Daimler-Benz merge in 1998.

A broad ratio unfold from First to the Fifth was chosen to attenuate gas consumption and cut back powertrain noise throughout cruising. An aggressive First-gear ratio supplies glorious launch efficiency, and evenly spaced gear ratios present clean acceleration by the gears.

World-class effectivity is achieved by bodily and digital means. This transmission makes use of bearings to cut back friction in lots of places the place different transmissions might make the most of bushings. The transmission additionally makes use of a novel scavenging system that removes oil spun off of the rotating elements by centrifugal pressure by strategically positioned slots within the outdoors of the case. This saves power that may be consumed by inside elements rotating in oil. Lubricating holes within the clutches are additionally positioned to advertise fast passage of the transmission fluid by the discs, minimizing viscous losses as a consequence of trapped oil.

The shift schedule adapts to particular person driving fashion, driving state of affairs and street circumstances, altering shift factors based mostly on an accelerator pedal utilization, brake utilization, lateral acceleration, altitude and cargo on the automotive on account of grades. Electronically managed engine torque administration supplies fast wide-open-throttle up shifts and fast two-step (4-2 or 3-1) kick-down shifts which might be exceptionally clean.

Transmission ratios:

 

 

 

Gear W5A580 545RFE
1st 3.59 3.00
2nd 2.19 1.67 upshift / 1.50 kickdown
third 1.41 1.0
4th 1.00 0.75
fifth 0.83 0.67
Reverse 3.16 3.0

Fully adaptive digital management of all shifting makes shifts very clean. The system screens the transmission as shifts happen and adjusts hydraulic stress as wanted. In so doing, the controls make the powertrain really feel responsive with out harshness.

Driver recognition software program alters shift factors based mostly on accelerator pedal utilization, brake utilization and lateral acceleration. This doesn’t require a compromise between sporty and economical operation, neither is it a query of selecting one or the opposite.

A torque administration system makes use of engine torque modeling to facilitate clean transmission shifting. Because of digital throttle management, torque administration is extra subtle and covers a broad torque vary.

Torque converter clutch slippage is electronically modulated and supplies for partial engagement in Third, Fourth or Fifth gears. This ends in improved shift really feel, gas financial system, driveability and cooling. It can be utilized at decrease speeds to supply advantages over a broad velocity vary. The system disengages as required to supply optimum efficiency.

545RFE transmission options
(Standard on Limited and Overland, N/A on Laredo or SRT8)
The 545RFE five-speed transmission has been refined to supply smoother operation and higher financial system whereas bettering the efficiency and towing functionality of the automobile. To accomplish all this, a number of options had been added, together with a redesigned solenoid to supply quieter operation when shifting from “park” into “drive.” A turbine damper additionally improves NVH, associated to torque converter software.

The 545RFE continues to supply twin second-gear ratios to supply a stability of efficiency and gas financial system. Depending on driving circumstances, the transmission will choose the extra acceptable second gear. A secondary overdrive ratio will increase freeway gas financial system and reduces engine noise at excessive speeds.

Transmission ratios:

Gear W5A580 545RFE
1st 3.59 3.00
2nd 2.19 1.67 upshift / 1.50 kickdown
third 1.41 1.0
4th 1.00 0.75
fifth 0.83 0.67
Reverse 3.16 3.0

65RFE transmission options (6-speed)

(Standard with 2012-2013 5.7L)

 

The 65RFE computerized transmissions is a classy, multi-range, electronically managed transmission which mixes optimized gear ratios for responsive efficiency, cutting-edge effectivity options and low NVH. Other options embrace driver adaptive shifting and three planetary gear units to supply vast ratio functionality with exact ratio steps for optimum driveability. The three planetary gear units additionally make accessible a novel alternate second gear ratio. The major 2nd gear ratio matches between 1st and third gears for regular through-gear accelerations. The alternate second gear ratio (2 prime) permits smoother 4-2 kickdowns at excessive speeds to supply 2nd gear passing efficiency over a wider freeway cruising vary.

The hydraulic portion of the transmission consists of the transmission fluid, fluid passages, hydraulic valves, and numerous line stress management parts.

The major mechanical parts of the transmission encompass the next:

  • Three a number of disc enter clutches
  • Three a number of disc holding clutches
  • Five hydraulic accumulators
  • Three planetary gear units
  • Dual Stage Hydraulic oil pump
  • Valve physique
  • Solenoid pack

The Transmission Control Module (TCM) is the “coronary heart” or “mind” of the digital management system and depends on data from numerous direct and oblique inputs (sensors, switches, and so forth.) to find out driver demand and automobile working circumstances. Depending on the automobile configuration, the TCM could also be a standalone module or it could be housed together with the Powertrain Control Module (PCM) in a single module. With this data, the TCM can calculate and carry out well timed and high quality shifts by numerous output or management units (solenoid pack, transmission management relay, and so forth.).

Operation

The 65RFE transmission provides full digital management of all computerized up and downshifts, and options real-time adaptive closed-loop shift and stress management. Electronic shift and torque converter clutch controls assist defend the transmission from harm as a consequence of excessive temperatures, which might happen underneath extreme working circumstances. By altering shift schedules, line stress, and converter clutch management, these controls cut back warmth technology and enhance transmission cooling.

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To assist enhance effectivity, the transmission features a dual-stage transmission fluid pump with digital output stress management. Under most driving circumstances, pump output capability enormously exceeds that which is required to maintain the clutches utilized. The 65RFE pump-pressure management system screens enter torque and adjusts the pump stress accordingly. The major stage of the pump works constantly; the second stage is bypassed when demand is low. The management system additionally screens enter and output velocity and, if incipient clutch slip is noticed, the stress management solenoid responsibility cycle is different, growing stress in proportion to demand.

A high-travel torque converter damper meeting permits earlier torque converter clutch engagement to cut back slippage. Needle-type thrust bearings cut back inside friction. The 65RFE is packaged in a one-piece die-cast aluminum case. To cut back NVH, the case has excessive lateral, vertical and torsional stiffness. It can be designed to maximise the good thing about the structural mud cowl that connects the underside of the bell housing to the engine bedplate, enhancing general energy practice stiffness. Dual filters defend the pump and different parts. A cooler return filter is added to the customary primary sump filter. Independent lubrication and cooler circuits guarantee ample stress for regular transmission operation even when the cooler is obstructed or the fluid can not circulate as a consequence of extraordinarily low temperatures.

NOTE: Note that autos geared up with ERS (Electronic Range Select) don’t present 2nd gear in limp-in, as a result of the shift lever has no “2” or “1” place.

The hydraulic management system design (with out digital help) supplies the transmission with PARK, REVERSE, NEUTRAL, SECOND, and THIRD gears, based mostly solely on driver shift lever choice. This design permits the automobile to be pushed (in “limp-in” mode) within the occasion of a digital management system failure, or a state of affairs that the Transmission Control Module (TCM) acknowledges as doubtlessly damaging to the transmission.

The TCM additionally performs sure self-diagnostic capabilities and supplies complete data (sensor knowledge, DTC’s, and so forth.) which is useful in correct prognosis and restore. This data could be considered with the suitable scan software.

Transmission ratios:

Gear W5A580 545RFE 65RFE
1st 3.59 3.00 3.00
2nd 2.19 1.67 upshift / 1.50 kickdown 1.67
2nd Prime 1.50
third 1.41 1.0 1.0
4th 1.00 0.75 0.75
fifth 0.83 0.67 0.67
Reverse 3.16 3.0 3.0

5-Speed Transmissions – extra data
Gear Ranges

NOTE: After choosing any gear vary, wait a second to permit the chosen gear to interact earlier than accelerating. This is very essential when the engine is chilly. If there’s a have to restart the engine you should definitely cycle the important thing to the LOCK place earlier than restarting. Transmission gear engagement could also be delayed after restarting the engine if the secret is not cycled to the LOCK place first.

P (Park)
Supplements the parking brake by locking the transmission. The engine could be began on this vary. Never use P (Park) whereas the automobile is in movement. Apply the parking brake when leaving the automobile on this vary.

R (Reverse)
Shift into this vary solely after the automobile has come to an entire cease.

N (Neutral)
No energy is transmitted from the engine to the drive axle. When the brakes are launched, the automobile can roll freely. Do not interact in N (Neutral) place whereas driving besides to coast when the automobile is at risk of skidding (e.g., on icy roads).

NOTE: Towing the automobile, coasting, or driving for another motive with selector lever in N (Neutral) may end up in extreme transmission harm. Refer to “Recreational Towing” in Section 5 and “Towing a Disabled Vehicle” in Section 6 of your proprietor’s handbook.

D (Drive)
The transmission mechanically upshifts by fifth gear. The D (Drive) place supplies optimum driving traits underneath all regular working circumstances.

Electronic Range Select (ERS) Operation

The Electronic Range Select (ERS) shift management permits you to transfer the shifter left (-) or proper (+) when the shifter is within the D (Drive) place, permitting the collection of the specified prime gear. For instance, if the motive force shifts the transmission into 3 (third gear), the transmission won’t ever shift above third gear, however can shift right down to 2 (second) or 1 (first), when wanted.

NOTE: To choose the right gear place for max deceleration (engine braking), transfer the shift lever to the left “D(-)” and maintain it there. The transmission will shift to the vary from which the automobile can greatest be slowed down.

Screen show 1 2 3 4 D
Actual gear(s) allowed 1 1-2 1-3 1-4 1-5

Overdrive

The overdrive computerized transmission comprises an electronically managed fourth and fifth velocity (Overdrive). On prior technology fashions, the Overdrive “On/Off” button was mounted to the entrance facet of the shifter. For 2005-up fashions, the button is on the middle instrument panel swap array and is labeled as “Tow/Haul”. The transmission will mechanically shift from third gear to Overdrive if the next circumstances are current:

 

  • The transmission selector is in D (Drive)
  • The engine coolant has reached regular working temperature
  • Vehicle velocity is above roughly 30 mph (48 km/h)
  • The “Tow / Haul” button has not been activated
  • Transmission has reached regular working temperature

NOTE: If the automobile is began in extraordinarily chilly temperatures, the transmission might not shift into Overdrive and can mechanically choose essentially the most fascinating gear for operation at this temperature. Normal operation will resume when the transmission fluid temperature has risen to an appropriate stage.

If the transmission temperature will get extraordinarily sizzling, the transmission will mechanically choose essentially the most fascinating gear for operation at this temperature. If the transmission temperature turns into sizzling sufficient, the “TRANSMISSION OVERTEMP” message might show and the transmission might downshift out of Overdrive till the transmission cools down. After cooldown, the transmission will resume regular operation.

In excessive ambient temperatures with sustained excessive engine velocity and cargo, an upshift adopted shortly thereafter by a downshift might happen. This is a standard a part of the overheat safety technique when working within the “Tow / Haul” mode. The transmission will downshift from Overdrive to essentially the most desireable gear if the accelerator pedal is absolutely depressed at automobile speeds above roughly 35 mph (56 km/h).

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When To Use Tow/Haul Mode(all fashions besides SRT8)

When driving in hilly areas, towing a trailer, carrying a heavy load, and so forth., and frequent transmission shifting happens, press the “Tow / Haul” button. This will enhance efficiency and cut back the potential for transmission overheating or failure as a consequence of extreme shifting. When working in “Tow / Haul” mode, the transmission will shift to third gear and 4th will likely be enabled underneath regular cruise circumstances.

The “Tow / Haul” gentle will illuminate within the instrument cluster to point when the swap has been activated. Pressing the swap a second time restores regular operation. If the “Tow / Haul” mode is desired, the swap have to be pressed every time the engine is began.

Torque Converter Clutch

A function designed to enhance gas financial system is included in all computerized transmissions. A clutch inside the torque converter engages mechanically at a calibrated velocity at gentle throttle. It engages at greater speeds underneath heavier acceleration. This might end in a barely totally different feeling or response throughout regular operation in excessive gear. When the automobile velocity drops under a calibrated velocity, or throughout acceleration, the clutch mechanically and easily disengages. The function is operational in Overdrive and in Drive.

NOTE: The torque converter clutch is not going to interact till the transmission fluid and engine coolant are heat [usually after 1-3 miles (1.6 – 4.8 km) of driving]. Because the engine velocity is greater when the torque converter clutch shouldn’t be engaged, it could appear as if the transmission shouldn’t be shifting into Overdrive when chilly. This is regular. Pressing the “Tow / Haul” button, when the transmission is sufficiently heat, will reveal that the transmission is ready to shift into and out of Overdrive.

NOTE: If the automobile has not been pushed in a number of days, the primary few seconds of operation after shifting the transmission into gear could appear sluggish. This is because of the fluid partially draining from the torque converter into the transmission. This situation is regular and won’t trigger harm to the transmission. The torque converter will refill inside 5 seconds of shifting from Park into another gear place.

Rocking the Vehicle

If the automobile turns into caught in snow, sand, or mud, it may usually be moved by a rocking movement. Move the gear selector rhythmically between D (Drive) and R (Reverse), whereas making use of slight stress to the accelerator.

NOTE: The Electronic Stability Program (ESP) and Traction Control (if geared up) ought to be turned OFF earlier than making an attempt to rock the automobile. The least quantity of accelerator pedal stress to keep up the rocking movement with out spinning the wheels or racing the engine is only. Racing the engine or spinning the wheels, because of the frustration of not releasing the automobile, might result in transmission overheating and failure. Allow the engine to idle with the transmission selector in N (Neutral) for at the least one minute after each 5 rocking-motion cycles. This will reduce overheating and cut back the danger of transmission failure throughout extended efforts to free a caught automobile.

CAUTION! When “rocking” a caught automobile by transferring between “First” and R (Reverse), don’t spin the wheels quicker than 15 mph (24 km/h), or drivetrain harm might outcome.

Autostick

Autostick is a driver-interactive transmission that gives handbook gear shifting functionality to supply the motive force with extra management. Autostick permits the motive force to extend engine braking capacity, management upshift and downshift factors, and improve the driving expertise. This system can even present the motive force with extra management throughout passing, metropolis driving, mountain driving, trailer towing, and lots of different conditions.

Autostick Operation

By inserting the shift lever within the D (Drive) place the lever could be moved back and forth. This permits the motive force to interact the AutoStick mode. Moving the shift lever to the appropriate (+) or the left (-) will interact the Autostick mode. In regular driving mode (Boxed “D” displayed within the PRNDL), transferring the shift lever to the appropriate (+) will interact the Autostick mode placing the transmission within the at the moment engaged gear. Moving the shift lever to the Left (-) will interact the Autostick mode and downshift the transmission 1 gear. For instance, the transmission is in Normal Mode and is at the moment working in third gear, a boxed D is displayed within the PRNDL, a push to the appropriate will interact the Autostick mode in third and a Boxed 3 will likely be displayed within the PRNDL. A push to the left (-) will interact Autostick mode and downshift to 2nd gear and a Boxed 2 will likely be displayed within the PRNDL. Once Autostick mode is engaged a transfer to the Right (+) or left (-) will set off a upshift (+) or set off a downshift (-).

NOTE: In the Autostick mode, the transmission will solely shift up and down when Left or Right (D-/D+) is manually chosen by the motive force.

The transmission is not going to honor a downshift command if the downshift would end in a engine overspeed situation. The transmission will at all times honor a upshift command from 1st to 2nd gear, nevertheless 2nd – third, third – 4th, and 4th – fifth upshift instructions is not going to be honored if the automobile velocity is to low to keep up operation within the commanded gear. The transmission will mechanically downshift because the automobile slows to a cease.

When within the Autostick mode, because the engine RPM nears the engine most velocity, an ‘UPSHIFT’ message will seem within the Electronic Vehicle Information Center (EVIC) portion of your instrument cluster. This message seems with a purpose to alert the motive force that the engine velocity is approaching it’s most worth and a upshift to the subsequent gear is required. In the occasion that the motive force does notupshift, the engine management system will restrict the engine velocity to guard the engine.

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Shifting into or out of the Autostick mode could be finished at any time with out taking your foot off the accelerator pedal. When the motive force needs to interact Autostick, merely transfer the shift lever to the Left or Right (D-/D+) place whereas in D (Drive).

Hold the shift lever to the appropriate for at the least one second to disengage Autostick. The transmission will now function mechanically; shifting between the 5 accessible gears.

Autostick General Information

 

  • You can begin out in first or second gear. The system will ignore makes an attempt to upshift at too low of a automobile velocity. The transmission will mechanically downshift to first gear when coming to a cease.
  • Starting out in second gear is useful in snowy or icy circumstances.
  • Avoid utilizing velocity management when Autostick is engaged.
  • The transmission is not going to mechanically shift up when most engine velocity is reached whereas Autostick is engaged.
  • Transmission shifting will likely be extra noticeable when Autostick is engaged.

 

ZF 8HP45 and 8HP70 transmission options (8-speed)

Jeep debut: 2014 Grand Cherokee (all fashions)

Chrysler Group LLC is the primary home automaker to function the state-of-the-art ZF eight-speed computerized transmission in its autos. The new 8HP45 digital eight-speed computerized transmission made its debut in V6 fashions of the 2012 Chrysler 300 and 2012 Dodge Charger. Next 12 months (1st quarter 2013) the brand new eight-speed will likely be supplied in a number of extra Chrysler autos, together with the 2013 Dodge Ram and all trim ranges of the refreshed 2014 Jeep Grand Cherokee.
Chrysler Group LLC will initially obtain the brand new 8-speed transmissions from the ZF Getriebe GmbH plant in Saarbrücken, Germany. In parallel with Chrysler Group, ZF is organising a brand new transmission manufacturing plant in North America, the place the 8-speed transmissions will likely be produced. Chrysler Group is licensed to provide the brand new 8HP’s on the firm’s Indiana Transmission Plant I and the Kokomo casting plant, beginning in 2013.

Compact and light-weight, the brand new transmission required no structural modifications to both automobile and regardless of the addition of extra gears, the transmission really weighs simply 3kg greater than the outgoing 5 velocity computerized transmission. The addition of three extra gear ratios within the confirmed ZF eight-speed computerized transmission design assist to cut back the gaps usually related to upshifting and downshifting. Passengers will expertise world-class ranges of refinement as a consequence of small, evenly spaced ratios that present faster acceleration and smoother shifts.

Fully digital and aided with software program that gives an adaptive shifting technique, the 845RE has been designed to supply optimum shifting traits in line with the Chrysler and Dodge manufacturers. Adaptive shifting takes into consideration plenty of variables together with engine torque gradients, kick down, longitudinal and lateral acceleration, hill detection, friction detection and downshift detection in figuring out shift patterns. Additional parameters embrace automobile velocity management, digital stability management activation and excessive temperatures that may have an effect on transmission shifting.

High efforts in shifting even have been eradicated with gear choice managed by a shift-by-wire system. The place chosen by the motive force (P, R, N, D) is transmitted electronically with no mechanical linkage from the shifter to the surface of the transmission. Elimination of this linkage removes any shift effort from the motive force’s gear choice. Shift-by-wire additionally permits improved calibration and smoothness of storage and car parking zone shifts.

All shifts, whether or not single, double or a number of are carried out as a direct results of the pedal place. Downshifts are made with very brief response instances and lead on to the requested gear. Multiple upshifts could be decoupled briefly if the torque request modifications through the upshift. This helps get rid of the shift looking out of the transmission.

Quicker shifts are attainable on account of a “Sport” shift mode that requires easy driver enter. When the motive force chooses to let the transmission shift in “Sport” mode, gear modifications are faster and revs are held greater for much more performance-oriented acceleration and better shift dynamics. For much more management, the motive force can even use a pair of die-cast steering-wheel mounted paddle controls and look at gear choice by an all-new full-color EVIC centered in instrument cluster.

Additionally, decrease viscosity transmission fluid is used leading to improved transmission effectivity and gas financial system enhancements particularly throughout chilly environments or automobile start-up. The 845RE is also “fill for all times” not requiring oil modifications throughout regular driving circumstances.

The 8HP45 Transmission Control Module Assembly (TCMA), which is built-in into the valve physique, supplies absolutely synchronized clutch-to-clutch shifting by 4 planetary gear units. The TCMA features a mounting plate that holds the Transmission Control Module (TCM) and a molded wiring harness for connection to numerous transmission sensors and solenoids. The valve physique meeting comprises all of the sensors and solenoids required for operation, fully contained in the transmission. Eight speeds enable the engine to keep up its optimum rpm vary, growing gas financial system and efficiency.

Transmission management is carried out by the TCM based mostly on hard-wired and CAN bus alerts from sensors and modules. The TCM receives driveability knowledge from the Powertrain Control Module (PCM) and different modules over the CAN-C bus. It additionally receives shift lever place data from the digital shifter over a devoted transmission CAN bus. The TCM processes this enter knowledge and controls operation of the torque converter clutch, park lock system, solenoid valves, and stress regulating valve.

The enter and output velocity sensors are Hall-effect sensors that measure shaft rotational velocity. The enter velocity sensor is situated on the prime, close to the middle, of the of the TCMA and reads enter shaft velocity from the magnetic ring on the P2 service. The output velocity sensor is situated in the back of the TCMA and reads output shaft velocity from the P4 service

8HP45 Gear Ratios:

1ST 4.69:1
2ND 3.13:1
3RD 2.10:1
4TH 1.67:1
5TH 1.28:1
6TH 1.00:1
7TH 0.84:1
8TH 0.67:1
REVERSE 3.30:1

–Wk2Jeeps.com

 

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