Cylinder Block - Inspection (Cont'd): Piston Ring Gap / Main Bearing Clearance
EM-240spec tablePiston ring gap specifications given separately for CD17 and CD20 diesel engines.
Inspection (Cont'd)
PISTON RING GAP
Ring gap:
Piston Ring Gap - CD17 (Unit: mm (in))
Top ring
Standard0.20 - 0.35 (0.0079 - 0.0138)
Limit1.0 (0.039)
2nd ring
Standard0.20 - 0.35 (0.0079 - 0.0138)
Limit0.7 (0.028)
Oil ring
Standard0.30 - 0.45 (0.0118 - 0.0177)
Limit0.6 (0.024)
Piston Ring Gap - CD20 (Unit: mm (in))
Top ring
Standard0.12 - 0.30 (0.0047 - 0.0118)
Limit1.0 (0.039)
2nd ring
Standard0.38 - 0.53 (0.0150 - 0.0209)
Limit0.7 (0.028)
Oil ring
Standard0.30 - 0.55 (0.0118 - 0.0217)
Limit0.6 (0.024)
If out of specification, replace piston ring. If gap still exceeds the limit even with a new ring, rebore the cylinder and use oversize piston/piston ring assembly. Refer to S.D.S.
Main Bearing Clearance
- 1Install main bearings to cylinder block and main bearing cap.
SEM600A - 2Install main bearing cap with bearing to cylinder block. Tighten all bolts in two or three stages: 44 - 54 N·m (4.5 - 5.5 kg-m, 33 - 40 ft-lb).
- 3Measure inside diameter "A" of main journal.
- 4Measure outside diameter "Dm" of main journal of crankshaft. Journal diameter: Refer to S.D.S.
SEM506A - 5Calculate main bearing clearance. Main bearing clearance = A - Dm. Standard: 0.039 - 0.065 mm (0.0015 - 0.0026 in). If it exceeds the limit, replace the bearing.
| Specification | Value |
|---|---|
| Main bearing cap bolts (tighten in two or three stages)4.5 - 5.5 kg-m, 33 - 40 ft-lb | 44 - 54N·m |
| Main bearing clearance (Standard)0.0015 - 0.0026 in | 0.039 - 0.065mm |
Main bearing cap bolts (tighten in two or three stages)4.5 - 5.5 kg-m, 33 - 40 ft-lb
44 - 54N·m
Main bearing clearance (Standard)0.0015 - 0.0026 in
0.039 - 0.065mm
See also
S.D.S.