1987 MAZDA 626 Workshop Manual

INSPECTION AND REPAIR 1 B
Rolled fillet
Crankpin journal diameter undersize mm (in)
Bearing size Journal diameter
0.25 (0.010) undersize 50.690-50.705 (1.9957—1.9963)
0.50 (0.020) undersize 50.440—50.455 (1.9858-1.9864)
0.75 (0.030) undersize 50.190-50.205 (1.9760-1.9766)
Caution
Do not grind the rolled fillet area.
76G01A-133
Main Bearing and Connecting Rod Bearing
Check the main bearings and the connecting rod
bearings for peeling, scoring, or other damage.
79G01C-077
Oil Jet
1. Check that the oil passage is not clogged.
2. Check that the check ball is not stuck.
76G01B-069
Timing Belt
1. Replace the timing belt if there is any oil or grease
on it.
2. Check the timing belt for damage, wear, peeling,
cracks, or hardening. Replace if necessary.
86U01X-101
1B—46

INSPECTION AND REPAIR 1 B
Caution
a) Never forcefully twist, turn inside out, or
bend the timing belt.
b) Be careful not to allow oil or grease on the
belt.
86U01X-114
Timing Belt Tensioner and Idler Pulley
Check the timing belt tensioner and idler pulley for
smooth rotation and abnormal noise. Replace if
necessary.
Caution
Do not clean the tensioner with cleaning
fluids. If necessary, use a soft rag to wipe it
clean, and avoid scratching it.
86U01X-115
Timing Belt Tensioner Spring
Check the free length of the tensioner spring. Replace
if necessary.
Free length: 53.3 mm (2.098 in)
76G01B-126
Timing Belt Pulley and Camshaft Pulley
Inspect the pulley teeth for wear, deformation, or other
damage. Replace if necessary.
Caution
Do not clean the pulley with cleaning fluids.
If necessary, use a rag to wipe it clean.
Timing Belt Cover (lower and upper)
Inspect the timing belt covers for damage or cracks.
Replace if necessary.
86U01X-101
1B—47

1 B ASSEMBLY (CYLINDER BLOCK)
ASSEMBLY
1. Clean all parts before reinstallation.
2. Apply new engine oil to all sliding and rotating parts.
3. Replace plain bearings if they are peeling, burned, or otherwise damaged.
4. Tighten all bolts and nuts to the specified torques.
Caution
Do not reuse gaskets or oil seals.
CYLINDER BLOCK—I
Torque Specifications
69G01A-139
1B—48

ASSEMBLY (CYLINDER BLOCK) 1 B
76G01B-070
76G01B-071
Connecting Rod
1. Align the identification mark to the cap of large end
of connecting rod and F mark on the piston as
shown in the figure.
2. Apply a coat of engine oil to the circumference of
each piston pin and to the small end of each con-
necting rod.
3. Set a clip into the clip groove in one side of the
piston.
4. Insert the piston pin into the piston and connect-
ing rod from the opposite side of the piston with
the SST .
5. Tap the piston pin in until it touchs the clip. Install
the other clip into the groove in the piston.
6. Check the oscillation torque of the connecting rod.
(Refer to page 1B—33.)
Piston Ring
1. Install the three-piece oil rings on the pistons.
(1) Apply engine oil to the oil ring spacer and rails.
(2) Install the oil ring spacer so that the opening
faces upward.
(3) Install the upper rail and lower rail.
Note
a) The upper rail and lower rail are the same.
b)Each rail can be installed with either face
upward.
69G01A-144
1B—49

1 B ASSEMBLY (CYLINDER BLOCK)
Spacer tang
Oil ring
spacer ends
Upper rail
Piston
Lower rail
69G01A-145
86U01X-121
Oil ring —
upper rail / N. ^ Top ring
Oil ring I ^_t30° L^Pistion
T Pin spacer I ^_t30° L^Pistion
T Pin
Oil ring
lower rail N. j/ Second ring
69G01A-147
2. Check that both rails are expanded by the spacer
tangs as shown in the figure by checking that both
rails turn smoothly in both directions.
3. Install the second ring to the piston first, then in-
stall the top ring. Use a piston ring expander.
Caution
The rings must be installed with the "R"
marks facing upward.
4. Apply a liberal amount of clean engine oil to the
second and top piston rings.
5. Position the opening of each ring as shown in the
figure.
Crankshaft
1. Before installing the crankshaft, inspect the main
bearing oil clearances as described.
Note
The bearing with thrust shoulders is the cen-
ter bearing in the cylinder block.

86U01X-136

1B—50

ASSEMBLY (CYLINDER BLOCK) 1 B
Oil clearance inspection
(1) Remove any foreign material and oil from the
journals and bearings.
(2) Install the upper main bearings in the cylinder
block.
(3) Set the crankshaft into the cylinder block.
(4) Position the plasti-gauge on top of the journals
in the axial direction.
86U01X-122
(5) Install the main bearing caps along with the
lower main bearings according to the cap num-
ber and mark.
(6) Tighten the caps in two or three steps in the
order in the figure.
Tightening torque:
82—88 Nm (8.4—9.0 m-kg, 61—65 ft-lb)
Caution
Do not rotate the crankshaft when measuring
the oil clearances.
86U01X-123
(7) Remove the main bearing caps, and measure
the plasti-gauge at each journal at the widest
point for the smallest clearance, and at the nar-
rowest point for the largest clearance.
If the oil clearance exceeds specification, grind
the crankshaft and use undersize main bear-
ings. (Refer to page 1B—45.)
Oil clearance
No. 1, 2, 4, 5:
0.025—0.043 mm (0.0010—0.0017 in)
No. 3:
0.031—0.049 mm (0.0012—0.0019 in)
Maximum: 0.08 mm (0.0031 in)
Apply a liberal amount of engine oil to the main
bearings and main journals.
Install the crankshaft and the main bearing caps
according to the cap number and ^ mark.
86U01X-125
1B—51

1 B ASSEMBLY (CYLINDER BLOCK)
76G01A-074
86U01X-216
76G01 B-075
4. Inspect the crankshaft end play.
End play:
0.08—0.18 mm (0.0031—0.0071 mm)
Maximum: 0.30 mm (0.012 in)
5. If the end play exceeds specification, grind the
crankshaft and use undersize center main bearing.
Center main bearing width
Standard:
27.94—27.99 mm (1.1000—1.1020 in)
0.25 mm (0.010 in) undersize:
28.04—28.09 mm (1.1040—1.1059 in)
0.50 mm (0.020 in) undersize:
28.12—28.17 mm (1.1071—1.1091 in)
0.75 mm (0.030 in) undersize:
28.20—28.25 mm (1.1102—1.1122 in)
Note
Wider thrust width is available only in under-
size center main bearing.
Pilot Bearing
1. Apply engine oil to the outer circumference of the
bearing.
2. Set a piece of pipe (outer diameter 30—34 mm,
1.18—1.34 in) against the outer race of the bear-
ing, then tap it evenly into the crankshaft.
3. Lubricate the bearing with grease.
Piston and Connecting Rod Assembly
1. Apply a liberal amount of clean engine oil to the
cylinder walls, piston, and rings.
2. Check the piston rings for the end gap alignment.
3. Insert each piston assembly into the cylinder block
with the F mark facing the front of the engine. Use
a piston installer tool (commercially available).
76G01A-136
1B—52

ASSEMBLY (CYLINDER BLOCK) 1 B
Connecting Rod Cap
1. Check the connecting rod bearing clearances us-
ing the same procedure as used for the main bear-
ing oil clearance.
Connecting rod cap tightening torque:
69—73 Nm (7.0—7.4 m-kg, 51—54 ft-lb)
Oil clearance:
0.027—0.067 mm (0.0011—0.0026 in)
Maximum: 0.10 mm (0.0039 in)
76G01B-076
Caution
Align the alignment marks on the cap and on
the connecting rod when installing the con-
necting rod cap.
2. If the oil clearance exceeds specification grind the
crankshaft and use undersize bearings. (Refer to
page 1B—46.)
76G01B-077
3. Check the side clearance of each connecting rod
without the cap installed.
Side clearance:
0.110—0.262 mm (0.004—0.0103 in)
Maximum: 0.30 mm (0.012 in)
If the clearance exceeds the maximum, replace the
connecting rod.
69G01B-139
4. Apply a liberal amount of engine oil to the crank-
pin journal and connecting rod bearing.
5. Install the connecting rod cap with the alignment
marks aligned.
Tightening torque:
69—73 Nm (7.0—7.4 m-kg, 51—54 ft-lb)
76G01B-078
1B—53