Pure Drivetrain 8HP51 High Performance Transmission Hard Parts Kit - AWD - Stage 2
The ZF 8HP51 is the third-generation 8-speed that BMW has fitted behind its B48 four-cylinder and B58 six-cylinder engines since 2018. In xDrive form it is coded GA8HP51X and lives in cars like the G20 M340i xDrive, the G05 X5 xDrive40i and the G01 X3. Those B58 cars respond so well to a tune, a downpipe and an upgraded turbo that the transmission becomes the limit long before the engine does. If your xDrive car now flares on the 3-4 upshift at full boost, slips when the fluid is hot, or you are planning a big-turbo build and want the gearbox done once, the Pure Drivetrain Solutions 12-94-2000 Stage 2 hard parts kit is built for that job.
Every gear in an 8HP comes from two of five shift elements (two brakes and three clutches) being applied at the same time, so holding power is only as good as the friction packs and the hubs that drive them. Pure Drivetrain's HPK replaces the clutch content with its own FSR friction plates and C6X steels and pressure plates, and adds heat treated, hard anodized billet 7075 aluminum hubs. According to the maker, the hubs are reworked to pass more fluid through each hub for cooling, the clutch tooth profiles and mating tooth profiles are revised for strength, and the base shoulder is extended to better support the clutch base plates. Stage 2 is the higher-capacity of the two stages Pure Drivetrain offers for the 8HP51; the 8HP51 AWD Stage 1 kit is the lighter-duty option for milder builds.
A kit at this price only makes sense if the clutches are the real problem. Start with the fluid level, set at the correct temperature with the ZF procedure, because a low 8HP will slip and shift badly with perfectly good clutches. Scan the EGS module for stored faults and look at adaptation values. Pure Drivetrain also lists solenoids clogged with wear debris as a common 8HP51 issue, and a sticking solenoid can feel exactly like a slipping clutch. Our ZF8HP pressure control solenoid guide walks through telling the two apart, and the BMW 3 Series 8-speed shift problems guide covers the software and adaptation issues to rule out first.
This kit is listed for the all-wheel-drive ZF 8HP51. Pure Drivetrain identifies the Gen 3 8HP51 behind the B47 and B58 engines in G-series BMWs, and it was also used in the Jaguar XE and Toyota Supra (the Supra is rear drive, so it takes the RWD kit). The 8HP51 shares its bellhousing pattern with the earlier 8HP50, but the G-series units use larger 18.5 mm cooler ports than the F-series 8HP50, which is a good reminder that close is not the same as identical. Read the ZF tag on the case and send it with your year and VIN before ordering; Pure Drivetrain requires fitment confirmation on every HPK. If your tag reads 8HP76 instead, use the 8HP76 AWD Stage 2 kit. Browse everything for the 8-speed on our ZF 8HP collection page.
| Brand | Pure Drivetrain Solutions |
| Part number | 12-94-2000 |
| Fits | Pure Drivetrain 8HP51 High Performance Transmission Hard Parts Kit - AWD - Stage 2 |
| 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 the AWD 8HP51 in most model years, which is what this kit is listed for. Check the ZF tag on the case and send it with your VIN so the exact variant can be confirmed before you order.
No. Rear-drive cars use the GA8HP51Z, which takes the RWD version of this kit, part number 12-95-2000.
Pure Drivetrain FSR friction plates, C6X steels and pressure plates, and heat treated, hard anodized billet 7075 hubs. Seals, gaskets, fluid and labor are separate.
Start from a known-good calibration and reset adaptations, then run the quick learn. Many builders pair the kit with a transmission tune to raise clamping pressure, but the break-in comes first either way.
Pure Drivetrain requires 500 miles of easy stop-and-go driving, running up and down through the gears, before dyno or full-power use. Steady highway cruising does not break the clutches in.
Stage 2 is the higher holding-capacity step. Choose it for big-turbo or heavily modified builds; tell us your power level if you are not sure.
