Suzuki Engine 2002 GRAND VITARA SQ420 Service Manual page 459

6A2-84 ENGINE MECHANICAL (H25 ENGINE)
Crank Pin and Connecting Rod Bearings
• Crank pin diameter :
Inspect crank pin for uneven wear or damage. Measure
crank pin for out-of-round or taper with a micrometer. If crank
pin is damaged, or out-of-round or taper is out of limit,
replace crankshaft or regrind crank pin referring to the follow-
ing Step 6).
Crank pin and connecting rod bearing specification
Connecting rod bearing size
Standard
0.25 mm (0.0098 in.) under-
size
Crank pin out-of-round (A – B)
Limit : 0.01 mm (0.0004 in.)
Crank pin taper (a – b)
Limit : 0.01 mm (0.0004 in.)
• Connecting rod bearing general information :
Service connecting rod bearings are available in standard
size and 0.25 mm (0.0098 in.) undersize, and standard size
bearing has 5 kinds of bearings differing in tolerance.
For identification of undersize bearing, it is painted red at the
position as indicated in figure, undersize bearing thickness is
1.605 – 1.615 mm (0.0632 – 0.0635 in.) at the center of it.
1. Painting
• Connecting rod bearing visual inspection :
Inspect bearing shells for signs of fusion, pitting, burn or flak-
ing and observe contact pattern. Bearing shells found in
defective condition must be replaced.
• Connecting rod bearing clearance :
1) Before checking bearing clearance, clean bearing and crank
pin.
2) Install bearing in connecting rod and bearing cap.
3) Place a piece of gaging plastic (1) to full width of crank pin as
contacted by bearing (parallel to crankshaft), avoiding oil
hole.
Crank pin diameter
49.982 – 50.000 mm
(1.9678 – 1.9685 in.)
49.732 – 49.750 mm
(1.9580 – 1.9586 in.)