Pure Drivetrain 8HP51 High Performance Transmission Hard Parts Kit - AWD - Stage 1
Owners searching for an 8HP51 rebuild usually have the same story: a G20 M340i xDrive, a G05 X5 xDrive40i or another G-series BMW with a tune that has started to flare on hard upshifts, feels soft once the fluid is hot, or came out of a teardown with burnt clutches. The Pure Drivetrain Solutions 12-94-1000 is the Stage 1 hard parts kit for the all-wheel-drive version of that transmission. It is the entry point of Pure's two-stage 8HP51 program, aimed at the owner who is rebuilding anyway and wants the clutch packs and hubs to be stronger than what came out, without stepping up to the Stage 2 package.
The 8HP51 is ZF's third-generation 8-speed, in production since 2018 and listed by Pure Drivetrain at up to 560 Nm of input torque for engines up to 3.0 liters. The xDrive unit is coded GA8HP51X. Like every 8HP, it builds eight forward gears from four planetary sets and five shift elements, two brakes and three clutches, with three elements applied in each gear. That layout means one tired clutch pack shows up in several gears at once, and the hubs that carry torque into those packs have to survive every shift.
Pure's hard parts kits replace the factory friction content with its FSR friction plates, C6X steel plates and pressure plates, and swap in billet 7075 aluminum hubs that are heat treated and hard anodized. Pure does not publish a separate horsepower figure for Stage 1 versus Stage 2 on its product page, so tell us your engine, turbo and tune plan and we will help you decide whether Stage 1 covers it or whether the 8HP51 AWD Stage 2 kit is the safer choice.
Rule out the cheap causes first. Check the fluid level at the correct temperature, because a low 8HP slips with healthy clutches. Scan the transmission module for faults and log slip during a pull. Pure also lists solenoid contamination from wear debris as a recurring 8HP problem, and a sticking pressure regulator can feel exactly like a weak pack; our ZF8HP pressure control solenoid guide shows how to tell them apart. The BMW 3 Series 8HP problems guide covers the leak, software and adaptation issues worth checking on G-series cars.
Part number 12-94-1000 is the AWD 8HP51 kit. Pure lists the 8HP51 in G-series BMWs including the 3 Series G20, 4 Series G22, 5 Series G30, X3 G01, X5 G05 and X7 G07, as well as the Jaguar XE and the Toyota Supra. Only all-wheel-drive units take this part number, so a rear-drive Supra or a non-xDrive BMW needs the RWD kit. Some of these vehicles were also built with the larger 8HP76, so read the ZF tag on the case and send it with your year and VIN before ordering; Pure requires fitment confirmation on every hard parts kit. Browse all of our 8-speed parts on the ZF 8HP collection page.
| Brand | Pure Drivetrain Solutions |
| Part number | 12-94-1000 |
| Fits | Pure Drivetrain 8HP51 High Performance Transmission Hard Parts Kit - AWD - Stage 1 |
| Type | Transmission Rebuild Kits |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Both use Pure Drivetrain's FSR frictions, C6X steels, pressure plates and billet 7075 hubs. Stage 2 is the higher-capacity option. Pure does not post a power rating per stage, so send us your build details and we will help match the stage to your power level.
No. This part number is for the AWD (xDrive) 8HP51. Rear-drive 8HP51 transmissions need the RWD kit.
Read the ZF identification tag on the transmission case. The same model lines were offered with different 8HP versions depending on engine, so send us the tag details or your VIN before ordering.
Neither. It is a set of hard parts installed during a full rebuild, so the transmission has to be removed and disassembled.
ZF LifeguardFluid 8, or a fluid Pure Drivetrain approves. Pure lists 8.8 liters total capacity for the 8HP51, and the level must be set at temperature with the engine running.
Yes. Start from a known-good calibration, clear codes, reset adaptations and run the 8HP quick learn, then drive at least 500 miles of mixed driving before full-power use.
