Adapter Mercedes-Benz M104 - 6-speed manual BMW N54 GS6-53BZ 135i 335i 535i - 240mm / 9.45"

PMC Motorsport adapter / conversion kit / clutch kit Mercedes-Benz M104 – 6-speed manual BMW N54 ZF GS6-53BZ 135i 335i 535i – 240 mm / 9.45"

Adapter kit allowing connection (swap / conversion) of the Mercedes-Benz M104 engine with the 6-speed manual gearbox ZF GS6-53BZ used in BMW with N54 engine. An ideal solution for amateur and professional motorsport.

Planning a Mercedes-Benz M104 swap in your BMW (E30, E36, E46, E34, E39, E90, E91, E92, E60, E61, E81, E82, E87)? Our adapter is a reliable solution. Swap your automatic transmission for a manual BMW gearbox and unlock new possibilities.

PMC Motorsport adapters not only enable automatic to manual gearbox conversion in vehicles with the Mercedes-Benz M104 engine, but also support completing M104 swaps in BMW as well as other vehicles such as Nissan (S13, S14, S15, PS13) or Mazda RX-7 / RX-8.

Aluminum gearbox adapter designed to simplify gearbox installation as much as possible without radical modifications like cutting off the bellhousing – only preparing a cutout for the starter motor is required. Custom flywheels dedicated to PMC Motorsport adapters are made of aluminum with a replaceable friction surface, tested and balanced before shipping. Flywheel designed for 240 mm pressure plate (GS5-39DZ / GS6-53DZ / BZ BMW OE).

PMC Motorsport gearbox adapters are synonymous with precision and top quality. The design process based on 3D scanning and inspection using a measuring arm ensure a perfect fit. Production on modern CNC machines guarantees ideal concentricity of the engine and transmission, which is crucial for the durability of the drivetrain.

Additional information

Installation instructions

To install the flywheel, it is necessary to use the flexplate / starter ring gear from automatic version Mercedes-Benz OE 111-030-07-12 (not included). For adapter installation, a Mercedes-Benz M104 OE starter motor must be used. Mount the clutch release fork on the lower position of the release bearing (in case of a dual-position bearing).

Frequently Asked Questions

Which engines does this adapter fit?

For Mercedes-Benz engines from the M104 family: 2.8 L (M104.94x), 3.2 L (M104.99x), AMG 3.4 L, and AMG 3.6 L (M104.941 / M104.992).

Which gearboxes does the adapter fit?

For 6-speed manual ZF GS6-53BZ gearbox from BMW with N54 engine in HGX, JGD, JGF, JGK versions (E60 535i, E9x 335i, E8x 135i, Z4 35i) and GS6X53BZ HGY.

Do I need to cut the gearbox bellhousing?

No. The adapter is designed to avoid cutting the bellhousing – only a cutout for the starter motor needs to be prepared.

What parts do I need to buy separately for installation?

Flexplate / starter ring gear from automatic version Mercedes-Benz OE 111-030-07-12. It is not included in the kit.

Which starter motor should be used?

Mercedes-Benz M104 OE starter motor.

Which clutch pressure plate fits the PMC flywheel?

240 mm (9.45") BMW OE type pressure plate – from BMW M57 / M57N / M57N2 / N54 / B58 / E46 M3 or Sachs Performance 883082.001243. Clutches from ACT / Spec / Tanaci are also often used – custom pressure plates must fit the BMW OE flywheel (M57 / M57N / M57N2 / N54 / B58). Use a clutch disc with splines matching your transmission, a dedicated release bearing kit, and a slave cylinder.

Does the adapter also fit the ZF 8HP automatic transmission?

Yes. The PMC Motorsport gearbox adapter itself is universal and fits most BMW gearboxes (applies to adapters manufactured after 2022). When converting to a ZF 8HP automatic transmission, the standard flywheel must be replaced with the PMC Motorsport 8HP torque converter adapter.

Can I buy only the adapter or only the flywheel?

Yes. Every component of the kit is available separately.

Does the price include customs duty when shipping outside the European Union?

No. Product price and shipping estimate do not include customs duties or extra fees that may apply in the destination country.

Can I buy with 0% VAT?

Yes, if you are a B2B customer outside Poland with an active EU VAT number (verified in VIES) or ordering for export outside the EU.

Is the included manual enough for installation?

The manual describes joining the engine and gearbox outside the chassis. Depending on the car, extra modifications may be needed: mounts, bushings, firewall, transmission tunnel, driveshaft length. Professional installation recommended.

It is worth noting that a lightweight single-mass flywheel provides uncompromising throttle response at the expense of eliminating factory dampening elements. This results in a more direct drivetrain operation, which can naturally increase the noise generated by the gearbox mechanism. This is a desirable characteristic in sports vehicles resulting from the rigid engine-to-drivetrain connection.