ZF 8HP automatic transmission
Oil volume reservoir in the ZF 8HP automatic transmission: failure symptoms and solutions
ZF’s 8HP torque converter automatic transmission represents a remarkable technological achievement, specifically designed to meet the requirements of rear-wheel drive and all-wheel drive vehicles. With an impressive torque range from 300 to 1,000 Nm, it demonstrates exceptional performance. This broad spectrum enables optimal adaptation to a wide variety of driving situations, whether in city traffic, on the motorway or in demanding off-road use.
With its targeted focus on mid-size and luxury vehicles as well as SUVs, ZF aims to offer a highly comfortable yet powerful driving experience. The precise tuning of the 8HP automatic transmission not only enables smooth and jerk-free gear changes, but also improved performance and acceleration to meet the demands of discerning drivers.
Since its introduction in 2009, ZF’s 8HP automatic transmission has established itself as a reliable choice for numerous automakers worldwide. It is valued not only for its outstanding performance, but also for its remarkable reliability. Compared to conventional automatic transmissions, the 8HP transmission shows none of the classic weak points often associated with this type of transmission.
If the oil volume reservoir goes on strike: Problems in the ZF 8HP transmission
Through continuous further developments, ZF has adapted the 8HP transmission several times to current trends in the driveline in order to meet the constantly growing requirements. One important development step was the integration of the start-stop function, which is now widely used in modern vehicles. To ensure the proper functioning of this function, the transmission was equipped with an additional oil volume accumulator. This accumulator plays a crucial role in maintaining the required oil pressure immediately after restarting the engine, thus ensuring smooth shifting behaviour.
However, there are isolated situations in which problems and defects can occur in connection with this oil volume reservoir. These problems can have various effects on the vehicle and are often manifested by the failure of the start-stop system, accompanied by a corresponding error message in the vehicle display. On some models, engine power may even be throttled back to prevent transmission damage.
In the worst case, persistent problems with the oil pressure accumulator can lead to severe transmission damage if not acted upon in time. Lack of or insufficient oil pressure can lead to unwanted wear of transmission components, which can ultimately affect the overall function of the transmission.
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Symptoms of a defective oil volume reservoir❌ Failure of the start-stop system |
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Reasons for failure❌ Defect of the oil volume accumulator |
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Solution✔️ Replacing the oil volume reservoir |
Repair solutions from VAICO
To effectively address this problem, VAICO has developed a solution in the form of two repair kits that provide a comprehensive repair. These repair kits provide an efficient and reliable method of replacing the defective oil volume reservoir while ensuring that the vehicle’s start-stop function and general shift performance are restored to proper working order.
The two repair kits from VAICO include an oil volume reservoir as well as a high-quality oil pan, including all necessary assembly materials (V20-4027).

The extended repair kit (V20-4027-XXL) also contains the exact amount of gear oil required.

This complete solution not only ensures correct installation, but also the long-term functionality of the transmission without the risk of unexpected loss of performance or damage.
Oil volume reservoir for ZF 8 HP automatic transmission, repair kits by VAICO.
The VAICO repair kits for the oil volume reservoir of the ZF 8HP automatic transmission offer a number of advantages: The repair kits offer an exclusive solution that is only available from VAICO. They feature a wide range of applications covering a variety of vehicles, making them an extremely versatile solution for different car models and makes. The EXPERT KITS+ contain an OE-quality oil volume reservoir as well as gaskets and assembly materials for a smooth and professional repair.
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Advantages of VAICO repair kits✔️ EXCLUSIVE only available from VAICO |