Pure Drivetrain 8HP70 High Performance Transmission Hard Parts Kit - AWD - Stage 2
The ZF 8HP70 holds up well at stock power, but a supercharged 6.4L HEMI Grand Cherokee or Durango, or a tuned xDrive V8 BMW, can push it past what the factory clutch packs were sized for. The usual story is a transmission that shifts perfectly around town and then flares on the 3-4 or 4-5 at full throttle, or slips in the higher gears when towing or pulling hard on a hot day. The Pure Drivetrain Solutions 12-89-2000 is the Stage 2 hard parts kit for the all-wheel-drive 8HP70, for builders who are rebuilding the unit anyway and want it to live behind serious power.
The 8HP70 was the first 8HP to reach production, in the 2008 BMW 760Li, and ZF rates it at 700 Nm. Its five shift elements, brakes A and B plus clutches C, D and E, are fed by individual pressure regulators in the mechatronic unit; on the 8HP45 and 8HP70, Sonnax maps them as EDS-1 for A, EDS-3 for B, EDS-5 for C, EDS-6 for D and EDS-4 for E, with EDS-7 controlling line pressure. Three elements are applied in each gear, so a weak C or E pack shows up in several gears.
The kit description for 12-89-2000 lists increased clutch counts across the packs, Pure's FSR friction plates and C6X steels, billet 7075 aluminum E and C hubs, upgraded pressure plates and clutch pistons, and a complete gasket and seal kit with a transmission filter. It is rated for builds over 1000 horsepower. The billet hubs matter on the 8HP70 because the factory hubs are a known weak spot once the clutches can hold more torque than the parts around them. This is the AWD version, built for transmissions that drive a transfer case.
Not every slip on an 8HP70 is the clutches. Sonnax documents wear in the clutch holding valve bores that lets solenoid feedback pressure escape, causing slips and flares that look like clutch failure and are fixed in the valve body instead. Check the fluid level at 30 to 50 C with the engine running, read faults, and watch slip and solenoid data on a hard pull. Our Grand Cherokee 8HP common problems guide covers the Jeep-specific issues, and the ZF8HP problems and fixes guide lays out the valve body and solenoid faults to rule out.
This kit fits the ZF 8HP70 in all-wheel-drive form. Published 8HP70 applications with AWD or 4x4 versions include the Jeep Grand Cherokee WK2 with the 5.7L or 6.4L HEMI (2014-2021), the 2021-up Grand Cherokee WL and L with the 5.7L, the Dodge Durango 5.7L and 6.4L, and xDrive BMW 5 Series (F10), 7 Series (F01/F02) and X5 (E70) 50i models. Other engines and model years on the same vehicles use the 8HP45, 8HP75 or a larger 8HP, so confirm the ZF type plate on the case reads 8HP70. Send us your year and VIN if you want us to confirm. All of our ZF 8-speed parts are on the ZF 8HP parts page.
Build it with the unit fully apart. Set each clutch pack clearance as you stack it, since added plates change the pack height, and use the gasket, seal and filter parts supplied in the kit. While the valve body is out, have the bores checked; pairing the hard parts with a ZF8HP shift kit or valve body repair addresses the pressure side of the same problem. Refill with ZF LifeguardFluid 8, the only fluid ZF approves for the 8HP alongside LifeguardFluid 9, and set the level hot through the fill plug. Reset adaptations, complete the adaptation drive, and tune the transmission calibration to suit the new clutch capacity before you put full power through it.
| Brand | Pure Drivetrain Solutions |
| Part number | 12-89-2000 |
| Fits | Pure Drivetrain 8HP70 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.
No. 12-89-2000 is the AWD version for transmissions that drive a transfer case. Rear-drive 8HP70 cars need the RWD part number.
Yes. The kit description lists a complete gasket and seal kit and a transmission filter along with the frictions, steels, billet E and C hubs, pressure plates and pistons.
Do not assume it. The same vehicle lines were built with several 8HP sizes depending on engine and year. Check the ZF type plate on the case, or send us the VIN, before ordering.
It is a good idea. Worn clutch holding valve bores leak pressure and cause flares that look like clutch slip, so checking or repairing the valve body protects the new clutch packs.
Use ZF LifeguardFluid 8. A dry unit takes more than a pan service, so have extra on hand and fill until it trickles from the fill plug with the engine running at 30-50 C fluid temperature.
Yes. Clear the old adaptation values and complete an adaptation drive with a capable scan tool, then have the transmission calibration adjusted for the higher clutch capacity.
