4t65e transmissions
06-26-2012, 09:22 PM
#61
I'd like to see proof the LNF 4t45e is any different, from my considerable research I've not come across a shred of evidence that it is any different than any other 4t45e. There is a good reason the LNF was detuned to 250/217, if it had any upgrades it would not have needed to be neutered.
The only difference that I know for certain is the flexplate, an 8 bolt rather than a 6 bolt pattern.
The only difference that I know for certain is the flexplate, an 8 bolt rather than a 6 bolt pattern.
06-26-2012, 10:29 PM
#62
the 4t45e has been run behind v6 engines since 99. the g6 gt comes with a 4t45e, and it runs the 3.5l vvt, producing 224hp and 220lb/ft torque. i know for a fact that this version of the 4t45e is no different than the 4 cylinder versions, aside from the final drive ratio. i cant see the hhr ss version being any different, there isnt a need for it. gm tends to build all versions of a transmission pretty much the same, aside from a couple small differences, like final drive ratio, and sometimes an additional friction and steel in a clutch pack. most of the difference comes in the tcm calibration, when the transmission is in front of more power there will generally be higher line pressure, but its not as big of a change as some may think.
06-27-2012, 02:31 AM
#65
Senior Member
the 4t45e has been run behind v6 engines since 99. the g6 gt comes with a 4t45e, and it runs the 3.5l vvt, producing 224hp and 220lb/ft torque. i know for a fact that this version of the 4t45e is no different than the 4 cylinder versions, aside from the final drive ratio. i cant see the hhr ss version being any different, there isnt a need for it. gm tends to build all versions of a transmission pretty much the same, aside from a couple small differences, like final drive ratio, and sometimes an additional friction and steel in a clutch pack. most of the difference comes in the tcm calibration, when the transmission is in front of more power there will generally be higher line pressure, but its not as big of a change as some may think.
06-27-2012, 03:20 AM
#67
Senior Member
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..
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..
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