Dodge D250 1990 Service Manual page 319

Out-of-Chassis Repairs Base Engine Components
Page 91-32 DODGE Turbo Diesel
13 mm, 15mm
To relocate the assembly, temporarily install the vibration
damper and a fabricated wire pointer. Put a fiat washer
between the pointer and gear housing to prevent damage to
the gear housing.
Rotate the crankshaft in the direction of rotation until the piston
contacts the plate.
Mark the vibration damper.