Ford 2003 Mustang Workshop Manual page 1310

7. NOTE: The oil groove on the thrust washer must face toward the rear of the engine (against the
crankshaft surface).
Push the crankshaft rearward and install the crankshaft upper thrust washer at the rear of the
No. 5 main boss.
8. NOTE: Rotate the jackscrews into the bearing caps enough to provide clearance to the cylinder
block prior to installing the bearing caps.
Install the lower main bearings into the main bearing caps and lubricate them with clean engine
oil.
9. Install the rear main bearing cap.
10. Install the remaining main bearing caps on the cylinder block and tap into place using a plastic
or dead-blow hammer.