Lisle Fan Clutc Spanner Wrench part number 44180.
For GM, Jeep and Dodge Trucks, Vans and SUVs With Pressed on Water Pump Pulleys.
The double-ended spanner wrench fits the holes in pressed-on water pump pulleys. Hold the pulley firm with the spanner wrench. Use the appropriate open end wrench to turn the fan clutch nut (41740 36mm turning wrench works on many applications).