Since it was first introduced in 2008, the ZF 8HP transmission family has been an extremely popular 8-speed automatic transmission. Because of its extreme versatility, this ZF 8 speed transmission can be found in everything from the Rolls-Royce Phantom, to a RAM pick up truck. It was sold as a kit to automakers, who would then use their own 8HP TCM software, along with the most appropriate torque converter for the engine. The Chrysler Corporation / FCA even bought the rights to produce their own version of the ZF 8HP transmission called the TorqueFlight 8. But as powertrain technology advances, a more up-to-date version of the ZF transmission was required. So they created the ZF 8HP75 transmission, which was optimized for use with high torque diesel engines, as well as more complicated hybrid systems.
What Transmission Do I Have?
8HP75 Transmission Overview
The ZF 8HP75 transmission transfers power from the engine to the road through 4 planetary gearsets and 5 multi-plate clutch pack. To increase both operating and fuel efficiency, the ZF 8HP75 transmission is designed to only keep two of its five clutches (3 rotating and 2 brake) open at any given time. This significantly reduces spin losses, and the little springs between the clutch friction elements, help to keep the clutch completely open to improve both efficiency and the transmission’s coasting function. This ZF 8HP transmission can also immediately downshift from 8th to 2nd gear when maximum performance is required.
To provide compatibility with hybrid drivetrain components, the ZF 8HP75 transmission control unit has been upgraded to process commands significantly faster. Some applications will have as many as 40 individual shift maps, along with compatibility with thermal management systems. The ZF 8HP75 hydraulic impulse oil storage system (8HP75 HIS System) has been reengineered to provide much faster reaction when coupled with an engine start/stop system. Additionally, the 8HP75 transmission works with shift-by-wire setups, and the ZF 8HP75 transmission fluid is said to last a lifetime of the vehicle. However, it is highly recommended to perform a transmission fluid change at normal intervals.
ZF 8HP75 Applications
| Model |
|---|
| BMW X5 |
| Infiniti QX56 |
| Lexus RX300 |
ZF 8HP75 Diagnostic Trouble Codes | DTC
| Trouble Code | Description |
|---|---|
| P0705 | Transmission Range Sensor Circuit Malfunction (PRNDL Input) |
| P0706 | Transmission Range Sensor Circuit Range/Performance |
| P0710 | Transmission Fluid Temperature Sensor Circuit |
| P0711 | Transmission Fluid Temperature Sensor Circuit Range/Performance |
| P0712 | Transmission Fluid Temperature Sensor Circuit Low Input |
| P0713 | Transmission Fluid Temperature Sensor Circuit High Input |
| P0714 | Transmission Fluid Temperature Sensor Circuit Intermittent P0715 |
| P0717 | Input/Turbine Speed Sensor Circuit No Signal |
| P0729 | Gear 6 Incorrect Ratio |
| P0730 | Incorrect Gear Ratio |
| P0731 | Gear 1 Incorrect Ratio |
| P0732 | Gear 2 Incorrect Ratio |
| P0733 | Gear 3 Incorrect Ratio |
| P0734 | Gear 4 Incorrect Ratio |
| P0735 | Gear 5 Incorrect Ratio |
| P0750 | Shift Solenoid 'A' |
| P0755 | Shift Solenoid 'B' |
ZF 8HP75 Recalls
– Recall ID – NHTSA: 16V24000 – ZF 8 Speed Automatic Transmission
— Summary
In April 2016, Fiat Chrysler / FCA recalled 811,290 Chrysler Group vehicles equipped with the ZF 8-speed transmission and monostable gear selector. These vehicles include:
2014-2015 Jeep Grand Cherokee
2012-2014 Chrysler 300
2012-2014 Dodge Charger
— Consequence
Due to the nature of the shifters design, it always returns to the center position, which may confuse some drivers. According to the recall, there may not be adequate warning to the driver when they open their door and the transmission is not in the Park position. In such a scenario, the vehicle may still be in gear or placed in Neutral. If this should happen, the vehicle could roll away unexpectedly, causing serious injury or damage. The death of Star Trek actor Anton Yelchin as been attributed to this shifters design.
— Remedy
Dealers were instructed to update the vehicle software to alter the shifter’s behavior. For more information, owners may contact Chrysler customer service at 1-800-853-1403 (refer to the Chrysler recall S27) or the National Highway Traffic Safety Administration at 1-888-327-4236
Recall 14V-161 / P13 – Failed Park engagement
2014 Ram 1500 5.7L Hemi and 8-speed automatic transmission
– Summary
According to the recall, some 125 copies of the 2014 Ram 1500 equipped to with the 8HP transmission may have had improperly machined Park rod guide plate mounting surfaces inside of the transmission case, which could cause the fasteners to loosen, preventing the Park prawl from fully engaging.
– Consequence
If the above condition occurs, the transmission may slip out of the park position and unexpectedly roll away, causing serious injury or property damage.
– Remedy
The transmission will have to be replaced. Concerned owners can contact Chrysler customer service at 1-800-853-1403. You can also contact the National Highway Traffic Safety Administration at 1-888-327-4236
8HP75 Transmission Specs
General – 8-speed automatic
Application – RWD/AWD/4WD
Variations – with/without engine stop/start HIS system, hybrid drive system and 4WD/AWD
Weight – 191 lbs +/-
Fluid Type – ZF Lifeguard 8
8HP75 Transmission Gear Ratios
**actual gear ratios may vary depending on application
***gear ratio spread 7.0:1 / gear ratio spread 7.8:1
What Transmission Do I Have?
First – 4.71/5.00
Second – 3.14/3.20
Third – 2.10/2.14
Fourth – 1.66/1.72
Fifth – 1.28/1.31
Sixth – 1.00/1.00
Seventh – 0.83/0.82
Eighth – 0.66/0.64
Reverse – 3.30/3.45
