W150 1/2 Ton Pickup 4WD L6-225 3.7L VIN E 1-bbl (1982)
Fig. 28 Measuring outer rotor clearance in pump body
With outer rotor inserted into pump body, press rotor to one side with fingers. If clearance between rotor and pump body is 0.014 inch or more,
replace oil pump assembly.
Fig. 29 Measuring clearance over rotor
With inner rotor inserted into pump body, place a straightedge across face between bolt holes. If a feeler gauge of 0.004 inch or more can be inserted
between rotors and straightedge, replace oil pump assembly.
Fig. 30 Measuring clearance between rotors
Shaft and both rotors should be replaced if tip clearance between inner and outer rotor exceeds 0.010 inch. Inspect oil pressure relief valve plunger for
scoring and free operation in its bore. The relief valve spring has a free length of 2-1/4 inches and should test between 22.3 and 23.3 lbs. when
compressed to 1-19/32 inch. Replace spring that fails to meet specifications.
Using new parts as required, assemble pump except for outer rotor and cover. Install oil pump on engine then coat inside of pump with oil to assure
priming. Install outer rotor and cover using new seal ring.
