Dodge RAM 1500 1998 Owner's Manual page 1365

9 - 142 ENGINE - 4.7L
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING
Before reinstalling used rings or installing new
rings, the ring clearances must be checked.
(1) Wipe the cylinder bore clean.
(2) Insert the ring in the cylinder bore.
NOTE: The ring gap measurement must be made
with the ring positioned at least 12mm (0.50 inch.)
from bottom of cylinder bore.
(3) Using a piston, to ensure that the ring is
squared in the cylinder bore, slide the ring downward
into the cylinder.
(4) Using a feeler gauge check the ring end gap
(Fig. 76). Replace any rings not within specification.
Fig. 76 Ring End Gap Measurement - Typical
1 - FEELER GAUGE
PISTON RING SIDE CLEARANCE
NOTE: Make sure the piston ring grooves are clean
and free of nicks and burrs.
(5) Measure the ring side clearance as shown (Fig.
77) make sure the feeler gauge fits snugly between
the ring land and the ring. Replace any ring not
within specification.
(6) Rotate the ring around the piston, the ring
must rotate in the groove with out binding.
Fig. 77 Measuring Piston Ring Side Clearance
1 - FEELER GAUGE
PISTON RING SPECIFICATION CHART
Ring Position
Clearance
Upper Ring .051-.094 mm
(0.0020-.0037
Intermediate 0.04-0.08 mm
Ring
(0.0016-0.0031
Oil Control Ring .019-.229 mm
(Steel Rails) (.0007-.0090
Ring Position Ring Gap
Upper Ring 0.20-0.36 mm
(0.0079-0.0142
Intermediate 0.37-0.63 mm
Ring
(0.0146-0.0249
Oil Control Ring 0.025-0.76 mm
(Steel Rail) (0.0099- 0.03
Groove Maximum
Clearance
0.11 mm
(0.004 in.)
in.)
0.10 mm
(0.004 in.)
in.)
.25 mm
(0.010 in.)
in.)
Wear Limit
0.43 mm
(0.0017 in.)
in.)
0.74 mm
(0.029 in.)
in.)
1.55 mm
(0.061 in.)
in.)
DR