engine LEXUS SC400 1991 Service Repair Manual

3. INSPECT CONNECTING ROD
A. Inspect connecting rod alignmentUsing a feeler gauge and rod aligner, check the connecting
rod alignment.w Check for bend.
Maximum bend:
0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
If bend is greater than maximum, replace the connecting rod
assembly.
w Check for twist.
Maximum twist:
0.15 mm (0.0059 in.) per 100 mm (3.94 in.)
If twist is greater than maximum, replace the connecting rod
assembly.
B. Inspect piston pin oil clearance (a) Using a caliper gauge, measure the inside diameter ofthe connecting rod bushing.
Bushing inside diameter: 22.005±22.014 mm
(0.8663±0.8667 in.)
(b) Using a micrometer, measure the piston pin diameter.
Piston pin diameter: 21.997±22.006 mm(0.8660±0.8664 in.)
(c) Subtract the piston pin diameter measurement from thebushing inside diameter measurement.
Standard oil clearance: 0.005±0.011 mm
(0.0002±0.0004 in.)
Maximum oil clearance: 0.05 mm (0.0020 in.)
If the oil clearance is greater than maximum, replace the
bushing. If necessary, replace the piston and piston pin as a
set.
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C. If necessary, replace connecting rod bushing(a) Using SST and a press, press out the bushing.
SST 09222±30010
(b) Align the oil holes of a new bushing and the connectingrod.
(c) Using SST and a press, press in the bushing.
SST 09222±30010
(d) Using a pin hole grinder, bore the bushing to obtain the
standard specified clearance (see step B above)
between the bushing and piston pin.
(e) Check the piston pin fit at room temperature.
Coat the piston pin with engine oil, and push it into the con-
necting rod with your thumb.
D. Inspect connecting rod bolts Using vernier calipers, measure the minimum diameter of the
compressed bolt at the measuring point.
Standard diameter: 8.2±8.3 mm
(0.325±0.327 in.)
Minimum diameter: 8.0 mm (0.315 in.)
If the diameter is less than minimum, replace the connecting
rod bolt.
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INSPECTION OF CRANKSHAFT
1. INSPECT CRANKSHAFT FOR RUNOUT(a) Place the crankshaft on V±blocks.
(b) Using a dial indicator, measure the circle runout at thecenter journal.
Maximum circle runout: 0.06 mm (0.0024 in.)
If the circle runout is greater than maximum, replace the
crankshaft.
2. INSPECT MAIN JOURNALS AND CRANK PINS (a) Using a micr ometer, measure the diameter of each main
journal and crank pin.
Main journal diameter: 61.984±62.000 mm
(2.4403±2.4409 in.)
Crank pin diameter: 51.982±52.000 mm (2.0465±2.0472 in.)
If the diameter is not as specified, check the oil clearance
(See page EM±77 or EM±80).
(b) Check each main journal and crank pin for taper andout±of±round as shown.
Maximum taper and out±of round: 0.02 mm
(0.0008 in.)
If the taper or out±of±round is greater than maximum, re-
place the crankshaft.
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REPLACEMENT OF CRANKSHAFT OIL
SEALS
1. REPLACE CRANKSHAFT FRONT OIL SEALHINT: There are two methods, A and B, to replace the oil seal
as follows:
A. If oil pump is removed from cylinder block: (a) Using a screwdriver, pry out the oil seal.
(b) Using SST and a hammer, tap in a new oil seal until itssurface is flush with the oil pump body edge.
SST 09316±60010 (09316±00010)
(c) Apply MP grease to the oil seal lip.
B. If oil pump is installed on cylinder block: (a) Using a knife, cut off the oil seal lip.
(b) Using a screwdriver, pry out the oil seal.
NOTICE: Be careful not to damage the crankshaft. Tape
the screwdriver tip.
(c) Apply MP grease to a new oil seal lip.
(d) Using SST and a hammer, tap in the oil seal until itssurface is flush with the oil pump body edge.
SST 09316 60010 (09316±00010)
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2. REPLACE CRANKSHAFT REAR OIL SEALHINT: There are two methods, A and B, to replace the oil seal
as follows:
A. If rear oil seal retainer is removed from cylinder block: (a) Using a screwdriver and hammer, tap out the oil seal.
(b) Using SST and a hammer, tap in a new oil seal until itssurface is flush with the rear oil seal retainer edge.
SST 09223±15030, 09608±30022 (09608±05010)
(c) Apply MP grease to the oil seal lip.
B. If rear oil seal retainer is installed on cylinder block: (a) Using a knife, cut off the oil seal lip.
(b) Using a screwdriver, pry out the oil seal.
NOTICE: Be careful not to damage the crankshaft.
Tape the screwdriver tip.
(c) Apply MP grease to a new oil seal lip.
(d) Using SST and a hammer, tap in the oil seal until itssurface is flush with the rear oil seal retainer edge.
SST 09223±15030, 09608±30022 (09608±05011)
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ASSEMBLY OF PISTON AND
CONNECTING ROD ASSEMBLIES
1. ASSEMBLE PISTON AND CONNECTING ROD(a) Install a new snap ring at one end of the piston pin hole.
HINT: Be sure that end gap of the snap ring is not aligned with
the pin hole cutout portion of the piston.
(b) Gradually heat the piston to about 80
C (176
F).
(c) Coat the piston pin with engine oil..
(d) Align the front marks of the piston and connecting rod, and push in the piston pin with your thumb.
(e) Install a new snap ring at the other end of the piston pin hole.
HINT: Be sure that end gap of the snap ring is not aligned with
the pin hole cutout portion of the piston.
2. INSTALL PISTON RINGS (a) Install the oil ring expander and two side rails by hand.
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(b) Using a piston ring expander, install the twocompression rings with the code mark facing up.
Code mark: No.1 1T
No.2 2T
(c) Position the piston rings so that the ring ends are asshown.
NOTICE: Do not align the piston ring ends.
3. INSTALL BEARINGS (a) Align the bearing claw with the groove of the connectingrod and connecting cap.
(b) I n s t a l l t h e b e a r i n g s i n t h e c onnecting rod and
connecting rod cap.
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ASSEMBLY OF CYLINDER BLOCK
(See Components on page EM±75)HINT:
wThoroughly clean all parts to be assembled.
w Before installing the parts, apply new engine oil to all
sliding and rotating surfaces.
w Replace all gaskets, O±rings and oil seals with new
parts.
NOTICE: Apply a generous amount of oil on the sliding
surface of the b earing, and not on the back of it or on the
surface to which it is installed.
1. INSTALL MAIN BEARINGS HINT: The No. 1 main bearing is different from the rest of the
bearing.
(a) Align the bearing claw with the claw groove of the mainbearing cap or cylinder block.
NOTICE: Install the bearing with the oil hole in the cylin-
der block.
(b) Instal the bearings in the cyli nder block and main
bearing caps.
2. INSTALL UPPER THRUST WASHERS Install the thrust washers under the No. 4 main journal posi-
tion of the block with the oil grooves facing outward.
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3. PLACE CRANKSHAFT ON CYLINDER BLOCK
4. INSTALL MAIN BEARING CAP AND LOWER THRUSTWASHERS
A. Place main bearing cap and lower thrust washers on cyl- inder block
(a) Install the lower thrust washers on the No. 4 mainbearing with the grooves facing outward.
(b) Install the main bearing caps in numerical order with the arrows facing forward.
B. Install main bearing cap bolts HINT:
wThe main bearing cap bolts are tightened in two
progressive steps (steps (b) and (d)).
w If any of the main bearing bolts break or deform, replace
them.
(a) Apply a light coat of engine oil on the threads and under
the heads of the main bearing cap bolts.
(b) First, install and uniformly tighten the 14 main bearing
cap bolts in several passes in the sequence shown.
Torque: 44 N Vm (450 kgf Vcm, 33 ft Vlbf)
If any one of the main bearing cap bolts does not meet the
torque specification, replace the main bearing cap bolt.
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(c) Mark the front of the main bearing cap bolt head withpaint.
(d) Second, retighten the main bearing cap bolts 90
in the
numerical order shown above.
(e) Check that the painted mark is now at a 90
angle to the
front.
(f) Check that the crankshaft turns smoothly.
(g) Check the crankshaft thrust clearance. (See step 5 on page EM±80)
5. INSTALL PISTON AND CONNECTING ROD ASSEMBLIES Using a piston ring compressor, push the correctly numbered
piston and connecting rod assemblies into each cylinder with
the front mark of the piston facing forward.
6. INSTALL CONNECTING ROD CAPS
A. Place connecting rod cap on connecting rod (a) Match the numbered c onnecting rod cap with the
connecting rod.
(b) Install the connecting rod cap by aligning the dowel pin to the corrosponding hole.
B. Install connecting rod cap bolts HINT:
wThe connecting rod cap bolts are tightened in two
progressive steps (steps (b) and (d)).
w If any of the connecting rod bolts break or deform,
replace them.
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