Transmission Type: ZF 8HP55A (0BK) Mileage: 35 km (Delivery Mileage / Brand New) Application: 4.0 TFSI V8 Quattro (435–450 hp) Compatible Years: 2014–2018 (Final D4 Facelift)

The PTS is a high-torque 8-speed Tiptronic (torque-converter automatic) manufactured by ZF. It is specifically paired with the $4.0\text{L}$ V10 Twin-Turbo engine in the Audi A8 and S8. With only 35 km of use, this unit is essentially a “new-old-stock” gearbox, offering factory-level tight tolerances for a vehicle that typically demands extreme smoothness and high-speed durability.

Technical Specifications

• Transmission Model: ZF 8HP55A (Audi 0BK series).

• Gear Ratios: 8 Forward / 1 Reverse.

• Torque Rating: Rated for up to $700\text{ Nm}$, comfortably handling the 600+ Nm output of the 4.0 TFSI.

• All-Wheel Drive: Includes an integrated Torsen center differential for the permanent Quattro system.

• Engine Match: Optimized for engine codes CTGA, CEUA, and CTGF.

Key Features

• Zero Wear: At 35 km, the internal planetary gear sets, brake bands, and clutch packs are in “as-delivered” condition.

• HIS (Hydraulic Impulse Storage): This unit features an integrated pressure accumulator that allows for lightning-fast restarts during “Start-Stop” operation, maintaining hydraulic pressure even when the engine is off.

• Shift Performance: The 8HP55A is famous for its “dual personality”—it provides Rolls-Royce levels of smoothness in “Comfort” mode but can execute shifts in under $200\text{ milliseconds}$ when “Dynamic” mode is engaged.

• Fuel Efficiency: The wide ratio spread (approx. 7.0:1) allows the V8 to cruise at very low RPMs at highway speeds, significantly reducing fuel consumption.

Installation & Compatibility Guide

1. Component Protection: Like all modern Audi transmissions, the PTS contains an internal TCU (Transmission Control Unit) that is part of the Immobilizer system. You must use Audi ODIS to “unlock” the unit and marry it to your vehicle’s VIN.

2. Fluid Check: Even though it has 35 km, if the unit has been in storage, it is best practice to verify the fluid level. It requires Audi G 060 162 A2 (Green) or ZF Lifeguard 8.

   • Warning: Do not mix with earlier 6-speed or 12V fluids.

3. Torque Converter: This unit typically includes the high-stall torque converter (Part No. 0BK 323 573 A). Ensure the converter is fully seated before mating the transmission to the engine block to avoid damaging the oil pump.

4. Cooling System: Ensure your A8’s transmission oil cooler is flushed before installation. If your previous gearbox failed mechanically, any metal debris left in the lines will instantly contaminate this “new” 35 km unit.

Inventory Note: The PTS is a direct interchange for codes NWK, NWM, SHG, and SHH in many 2015+ 4.0T applications.