ZF Lifeguardfluid 8, the factory-fill ATF for the ZF 8HP eight-speed in BMW, Chrysler, Dodge, Jeep, Ram, Audi and Land Rover. One liter; plan six to nine for a drain-and-fill.
This is ZF Lifeguardfluid 8, the automatic transmission fluid specified for the ZF 8HP family of eight-speed automatics (8HP45, 8HP55, 8HP70, 8HP75 and 8HP90). ZF's own part number for this fluid is S671.090.312. If your transmission carries the 8HP designation, it wants this fluid and nothing thinner or thicker — the wrong ATF is a common cause of a harsh or hunting eight-speed.
Fitment is broad. The 8HP runs behind rear-drive and all-wheel-drive BMW models from 2007 up, the Chrysler 300, Dodge Charger and Challenger, the Jeep Grand Cherokee, the Ram 1500 with the eight-speed, Audi A6/A7/A8 and Q7 with the eight-speed Tiptronic, and a long list of Jaguar and Land Rover models. Confirm your unit is a ZF 8HP (not a GM 8L or a Ford 8-speed) before you fill.
On the bench or on a lift, the 8HP is filled through the fill plug on the side of the pan with a pump, then leveled with the fluid at temperature — typically 30 to 40 degrees C — letting the excess drip from the standpipe. A single liter is a top-off; a pan-drop and filter service on most 8HP units takes roughly seven liters, so order enough to do the job in one pass.
Fresh fluid on the correct spec cleans up the two problems owners feel most: erratic or firm shifts as the miles pile on, and low-speed shudder or hesitation from oxidized ATF that has lost its friction stability.
| Fluid spec | ZF Lifeguardfluid 8 |
| OEM part reference | S671.090.312 |
| Volume | 1 liter |
| Fits | ZF 8HP45, 8HP55, 8HP70, 8HP75, 8HP90 eight-speed automatics |
| Container | Sealed bottle |
| Typical service fill | About 7 liters for a pan-drop and filter |
