Primary (Oil) Pump: Reassembly

Install pump drive and driven gears with reference marks (punch marks) facing upward, toward top of pump body. Install NEW "O" ring on primary pump. Install primary pump in torque converter bellhousing. Ensure centering pin on primary pump engages with hole in torque converter bellhousing.

Fig 1: Checking Pump Body-To-Pump Driven Gear Radial Play

Courtesy of BMW OF NORTH AMERICA, INC.