Measuring Outer Rotor Thickness; Measuring Inner Rotor Thickness; Measuring Outer Rotor Clearance In Housing; Measuring Clearance Between Rotors - Dodge 2001 Ram 1500 Owner's Manual

BR/BE
OIL PUMP (Continued)
Measure thickness and diameter of outer rotor. If
outer rotor thickness measures 20.9 mm (0.825 in.)
or less, or if the diameter is 62.7 mm (2.469 in.) or
less, replace outer rotor (Fig. 60).
Fig. 60 Measuring Outer Rotor Thickness
If inner rotor measures 20.9 mm (0.825 in.) or less,
replace inner rotor and shaft assembly (Fig. 61).
Fig. 61 Measuring Inner Rotor Thickness
Slide outer rotor into pump body. Press rotor to the
side with your fingers and measure clearance
between rotor and pump body (Fig. 62). If clearance
is 0.356 mm (0.014 in.) or more, replace oil pump
assembly.
Install inner rotor and shaft into pump body. If
clearance between inner and outer rotors is 0.203
mm (0.008 in.) or more, replace shaft and both rotors
(Fig. 63).
Place a straightedge across the face of the pump,
between bolt holes. If a feeler gauge of 0.102 mm
(0.004 in.) or more can be inserted between rotors
and the straightedge, replace pump assembly (Fig.
64).
Inspect oil pressure relief valve plunger for scoring
and free operation in its bore. Small marks may be
removed with 400-grit wet or dry sandpaper.
Fig. 62 Measuring Outer Rotor Clearance in
1 - PUMP BODY
2 - OUTER ROTOR
3 - FEELER GAUGE
Fig. 63 Measuring Clearance Between Rotors
1 - OUTER ROTOR
2 - FEELER GAUGE
3 - INNER ROTOR
The relief valve spring has a free length of approx-
imately 49.5 mm (1.95 in.). The spring should test
between 19.5 and 20.5 pounds when compressed to
34 mm (1-11/32 in.). Replace spring that fails to meet
these specifications (Fig. 65).
If oil pressure was low and pump is within specifi-
cations, inspect for worn engine bearings or other
reasons for oil pressure loss.
ASSEMBLY
(1) Install pump rotors and shaft, using new parts
as required.
(2) Position the oil pump cover onto the pump
body. Tighten cover bolts to 11 N·m (95 in. lbs.)
torque.
ENGINE 3.9L
Housing
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