GM Website info on 4 speed Auto for SS
10-01-2007, 04:35 PM
#12
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More Info:
2008 Hydra-Matic 4T45 (MN5, ME7)
2008 Model Year Summary
Hydra-Matic 4T45 four-speed electronically controlled automatic transmission.
● New Applications:
Saturn VUE (MN5/ME7) – All New Vehicle
Chevrolet HHR SS (MN5) – New Engine: ECOtec 2.0L I4 DI Turbo (LNF)
● Durability Enhancements
FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES
DURABILITY ENHANCEMENTS
To improve high-mileage durability, many components have been strengthened. Included are the input sun gear, which is shot peened and the input carrier pinion washers which will receive a new coating.
LOW MAINTENANCE
The 4T45 transaxle uses DEXRON® VI fluid, and is "fill-for-life", with no maintenance scheduled for normal operation. DEXRON® VI, was developed to behave more consistently during temperature and other environmental variations, as well as to provide even lubrication of the moving surfaces of the transmission and more stable shift performance in extreme conditions. Durability is also increased with the new fluid.
OVERVIEW
The Hydra-Matic 4T45 is an electronically controlled four-speed transaxle that achieves industry benchmark levels of reliability and shift quality. Precisely calibrated electronic controls enable the transmission to adapt to a variety of driving conditions providing the driver with consistent shift quality. All 4T45 transaxles use the proprietary GM ECCC (Electronic Controlled Capacity Clutch) technology for torque converter lock-up functions. ECCC allows a very small degree of controlled slip in the torque converter lockup clutch to isolate drivetrain pulses and contribute to smooth delivery of power. The transaxle's low-noise operation is a result of the high helix angle gears, an enclosed bell housing, and the random-pattern chain. Mass has been reduced through optimized case design and use of lightweight materials. Driver Shift Control (DSC) function is available that allows easier manual shifting of the gear ranges. On some models the floor-mounted shift lever can be moved rearward and to the right to enable the DSC, and momentary movements of the lever forward and rearward can respectively upshift and downshift the transaxle. Electronic controls prevent downshifting at speeds which would cause the engine to over-rev, and automatically downshift when the vehicle comes to a stop. The 4T45 has a modified channel plate and valve body which allows the ability to electronically change shifts as signaled by the driver pushing a switch on the gear selector lever. To use the feature in the Malibu application, for example, the driver shifts the gear selector from D to the D3 position, then pushes the selector switch to downshift to D2 and then D1. Upshifting from D1 to D2 and D3 is accomplished through the selector switch as well.
On the 4T45 ( ME7 ), hybrid applications, there are several different operating conditions, including an engine-off condition while the vehicle is stopped at a stoplight, battery recharge on deceleration, and electric motor assist on acceleration. To accommodate the electric motor and the duty cycle of engine-off operation, the 4T45 has been modified to enable normal operation by utilizing an electrically powered hydraulic auxiliary pump to maintain pressure to the Forward clutches The Pressure Switch Manifold has also modified for additional diagnostic capability..
2008 Hydra-Matic 4T45 (MN5, ME7)
2008 Model Year Summary
Hydra-Matic 4T45 four-speed electronically controlled automatic transmission.
● New Applications:
Saturn VUE (MN5/ME7) – All New Vehicle
Chevrolet HHR SS (MN5) – New Engine: ECOtec 2.0L I4 DI Turbo (LNF)
● Durability Enhancements
FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES
DURABILITY ENHANCEMENTS
To improve high-mileage durability, many components have been strengthened. Included are the input sun gear, which is shot peened and the input carrier pinion washers which will receive a new coating.
LOW MAINTENANCE
The 4T45 transaxle uses DEXRON® VI fluid, and is "fill-for-life", with no maintenance scheduled for normal operation. DEXRON® VI, was developed to behave more consistently during temperature and other environmental variations, as well as to provide even lubrication of the moving surfaces of the transmission and more stable shift performance in extreme conditions. Durability is also increased with the new fluid.
OVERVIEW
The Hydra-Matic 4T45 is an electronically controlled four-speed transaxle that achieves industry benchmark levels of reliability and shift quality. Precisely calibrated electronic controls enable the transmission to adapt to a variety of driving conditions providing the driver with consistent shift quality. All 4T45 transaxles use the proprietary GM ECCC (Electronic Controlled Capacity Clutch) technology for torque converter lock-up functions. ECCC allows a very small degree of controlled slip in the torque converter lockup clutch to isolate drivetrain pulses and contribute to smooth delivery of power. The transaxle's low-noise operation is a result of the high helix angle gears, an enclosed bell housing, and the random-pattern chain. Mass has been reduced through optimized case design and use of lightweight materials. Driver Shift Control (DSC) function is available that allows easier manual shifting of the gear ranges. On some models the floor-mounted shift lever can be moved rearward and to the right to enable the DSC, and momentary movements of the lever forward and rearward can respectively upshift and downshift the transaxle. Electronic controls prevent downshifting at speeds which would cause the engine to over-rev, and automatically downshift when the vehicle comes to a stop. The 4T45 has a modified channel plate and valve body which allows the ability to electronically change shifts as signaled by the driver pushing a switch on the gear selector lever. To use the feature in the Malibu application, for example, the driver shifts the gear selector from D to the D3 position, then pushes the selector switch to downshift to D2 and then D1. Upshifting from D1 to D2 and D3 is accomplished through the selector switch as well.
On the 4T45 ( ME7 ), hybrid applications, there are several different operating conditions, including an engine-off condition while the vehicle is stopped at a stoplight, battery recharge on deceleration, and electric motor assist on acceleration. To accommodate the electric motor and the duty cycle of engine-off operation, the 4T45 has been modified to enable normal operation by utilizing an electrically powered hydraulic auxiliary pump to maintain pressure to the Forward clutches The Pressure Switch Manifold has also modified for additional diagnostic capability..
10-02-2007, 07:53 AM
#13
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10-02-2007, 08:19 AM
#15
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Join Date: 07-17-2006
Location: Dallas, GA
Posts: 6,050
With small autos?
10-02-2007, 08:30 AM
#16
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Join Date: 04-26-2007
Location: Wisconsin
Posts: 291
10-02-2007, 08:50 AM
#17
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10-02-2007, 10:03 AM
#18
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Join Date: 10-14-2006
Location: So. Cal
Posts: 1,186
I never raced it all, just driving it the way most anyone would...
One morning I tried to drive to work and it wouldn't go into 2nd gear.
10-02-2007, 10:06 AM
#19
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Join Date: 08-17-2006
Location: Ottawa, Ontario
Posts: 1,851
2008 Model Year Summary
Getrag F23 five-speed manual car and truck transaxle
• Carryover from 2007 Model Year
LOW MAINTENANCE
"The F23 uses DEXRON III for 2007, and are filled-for-life, requiring no fluid changes for normal duty service. "
10-02-2007, 10:31 AM
#20
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Join Date: 07-17-2006
Location: Dallas, GA
Posts: 6,050
The manual at least has a resivour (sp) for the clutch. But in general, all manual tranny's are "filled for life". Always have been. Shavings inside an auto are bad, period. All it takes is one checkvalve to get stuck.