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ZF 8HP45 Transmission
There are only five friction locking elements (three multi-disc clutches, two multi-disc brakes), and in any gear just two are open. Further, a low-viscosity lubricant is used, which reduces spin losses. So total energy losses from drag through the transmission are under 2%.
Reaction and Holding Components
- ZF: Designed and built by ZF Friedrichshafen AG
- 8: 8 speed transmission
- H: Hydraulic
- P: Planetary Gear
- 45: 450 Max. gasoline torque (N.M)
Hydraulic system
Valve Body
The valve body is located inside the mechatronics module. It includes valves and channels for hydraulic control. The valve body is divided into a lower section and an upper section of the valve plate. They are seperated by an intermediate plate. The following components are in the lower section.
- 14 hydraulic valves
- 7 electronic pressure control valves
- 1 solenoid valve
- 1parking lock magnet to lock the parking lock
Hydraulic impulse oil storage
A hydraulic impulse oil storage is a spring piston accumulator which fills with oil and tensions the spring during operation. When the engine starts up, this "reserve" of around 100 milliliters is supplied to the hydraulics - in a flash - to supply oil to the shift elements in the transmission which are needed for setting off. Thus the vehicle is ready to move already 350 milliseconds after starting up the engine.
Oil Pump
A double vane-type compressor is used in the 8HP. Double means that the shape of the pump body enables two supplies in one rotation of the pump.
The oil pump is offset and chain-driven, so it is sized according to engineering requirements, rather than by dictates of a conventional location on a transmission main shaft. The pump itself is responsible for at least one percentage point of the fuel economy boost.
Gear Train
- 8 speed transmission
- 5 shift elements
- 4 planetary gear sets
- Can shift across several gears, the biggest being the 8th down to the 2nd gear
Operating Characteristics/Unique features
- At about 201 lbs, the weight of the 8HP is about 4.4-6.6 lbs less than the 6HP.
- Has three different shift speed levels.
- Has driver type adaption.
- Reduces fuel consumption by 3 percent compared to the 6HP.
http://www.thetruthaboutcars.com/2014/03/saturation-dive-zf-8-speed-automatic/
- BMW 1 Series (F20)
- BMW 3 Series (F30)
- BMW 5 Series (F10)
- Chrysler 300 V6
- Dodge Charger V6
- RAM 1500 V6 (2013- )
Applications of the ZF 8HP45
- http://www.zf.com/corporate/en_de/products/innovations/8hp_automatic_transmissions/lower_consumption/lower_consumption.html
- http://en.wikipedia.org/wiki/ZF_8HP_transmission
- http://www.caranddriver.com/features/zfs-8-speed-automatic-transmission
- Alldata