The 8-speed automatic transmission ZF 8HP55 was produced by the concern from 2009 to 2018 and was installed on powerful Audi models under the symbol 0BK, sometimes it is designated 8HP55A and 8HP55AF. There is a version of this gearbox for hybrid cars with the index 0BW or 8HP55AH.
1st generation of the 8HP family: 8HP45, 8HP55, 8HP70, 8HP90.
Specifications
| Production years | 2009 – 2018 |
| Type | automatic transmission |
| Number of gears | 8 |
| Type of drive | all wheel |
| Engine volume, l | up to 4.2 |
| Torque output, Nm | up to 700 |
| Recommended oil | ZF Lifeguard Fluid 8 |
| Oil capacity, liter | 9.0 |
| Replacing the oil | every 60,000 km |
| Replacing the filter | every 60,000 km |
| Gearbox lifespan, km | ~300 000 |
| Weight, kg | 141 |
Gear ratios ZF 8HP55
Using the example of a Audi A6 Quattro 2012 with a 3.0 TDi engine:
| Main | 2.375 |
| 1st | 4.714 |
| 2nd | 3.143 |
| 3rd | 2.106 |
| 4th | 1.667 |
| 5th | 1.285 |
| 6th | 1.000 |
| 7th | 0.839 |
| 8th | 0.667 |
| Reverse | 3.317 |
The transmission was installed on:
- Audi A4 B8 (8K) in 2011 – 2015;
- Audi A5 1 (8T) in 2011 – 2016;
- Audi A6 C7 (4G) in 2011 – 2018;
- Audi A7 C7 (4G) in 2011 – 2018;
- Audi A8 D4 (4H) in 2009 – 2017;
- Audi Q5 1 (8R) in 2012 – 2017.
Disadvantages of the ZF 8HP55 gearbox
- This is a very reliable gearbox, but is often coupled with particularly powerful engines.
- When driving aggressively, the solenoids quickly become clogged with friction wear products.
- Vibrations from burnt clutches gradually break down the oil pump bearings.
- Aluminum pistons and drums do not withstand constant sudden acceleration from a standstill.
- Bushings and rubber gaskets in all automatic transmissions in the line require regular updating.
