Main Bearing Cap Torque Values
Disassembly
CAUTION:
- When installing sliding parts such as bearings and pistons, apply engine oil on the sliding surfaces.
- Place removed parts, such as bearings and bearing caps, in their proper order and direction.
- When installing connecting rod nuts and main bearing cap bolts, apply new engine oil to threads and seating surfaces.
- Do not allow any magnetic materials to contact the ring gear, teeth of flywheel or drive plate, and rear plate.
Piston And Crankshaft
1. Place engine on a work stand.
2. Drain coolant and oil.
3. Remove timing chain.
4. Remove pistons with connecting rod.
- When disassembling piston and connecting rod, remove snap ring first. Then heat piston to 60 to 70°C (140 to 158°F) or use piston pin press stand at room temperature.
CAUTION:
- When piston rings are not replaced, make sure that piston rings are mounted in their original positions.
- When replacing piston rings, if there is no punch mark, install with either side up.
5. Loosen main bearing caps in numerical order as shown in figure.
6. Remove bearing caps, main bearings and crankshaft.
- Before removing bearing caps, measure crankshaft end play.
- Bolts should be loosened in two or three steps.
Inspection
Piston And Piston Pin Clearance
1. Measure inner diameter of piston pin hole "dp".
Standard diameter "dp": 18.987 - 18.999 mm (0.7475 - 0.7480 inch)
2. Measure outer diameter of piston pin "Dp".
Standard diameter "Dp": 18.989 - 19.001 mm (0.7476 - 0.7481 inch)
3. Calculate piston pin clearance. Dp - dp = -0.004 to 0 mm (-0.0002 to 0 inch)
If it exceeds the above value, replace piston assembly with pin.
Piston Ring Side Clearance
Side clearance:
Top ring 0.040 - 0.080 mm (0.0016 - 0.0031 inch)
Max. limit of side clearance: 0.1 mm (0.004 inch)
If out of specification, replace piston and/or piston ring assembly.
Piston Ring End Gap
End gap:
Top ring 0.20 - 0.44 mm (0.0079 - 0.0173 inch)
Oil ring 0.20 - 0.69 mm (0.0079 - 0.0272 inch)
Max. limit of ring gap:
Top ring 0.49 mm (0.0193 inch)
Oil ring 0.69 mm (0.0272 inch)
If out of specification, replace piston ring. If gap exceeds maximum limit with a new ring, rebore cylinder and use oversized piston and piston rings. Refer to Piston, Engine; Specifications.
- When replacing the piston, check the cylinder block surface for scratches or seizure. If scratches or seizure is found, hone or replace the cylinder block.
Connecting Rod Bend And Torsion
Bend:
Limit 0.15 mm (0.0059 inch) per 100 mm (3.94 inch) length
Torsion:
Limit 0.3 mm (0.012 inch) per 100 mm (3.94 inch) length
If it exceeds the limit, replace connecting rod assembly.
Cylinder Block Distortion And Wear
Clean upper surface of cylinder block. Use a reliable straightedge and feeler gauge to check the flatness of cylinder block surface. Check along six positions shown in figure.
Block surface flatness:
Standard: Less than 0.03 mm (0.0012 inch)
Limit: 0.10 mm (0.004 inch)
If out of specification, resurface it. The limit for cylinder block resurfacing is determined by the amount of cylinder head resurfacing.
Amount of cylinder head resurfacing is "A".
Amount of cylinder block resurfacing is "B".
The maximum limit is as follows:
A + B = 0.2 mm (0.008 inch)
Nominal cylinder block height from crankshaft center:
213.95 - 214.05 mm (8.4232 - 8.4271 inch)
If necessary, replace cylinder block.
Piston-To-Bore Clearance
1. Using a bore gauge, measure cylinder bore for wear, out-of-round and taper.
Standard inner diameter: 76.000 - 76.010 mm (2.9921 - 2.9925 inch)
Wear limit: 0.2 mm (0.008 inch)
Out-of-round (X - Y) standard: Less than 0.015 mm (0.0006 inch)
Taper (A - B) standard: Less than 0.01 mm (0.0004 inch
If it exceeds the limit, rebore all cylinders. Replace cylinder block if necessary.
2. Check for score and seizure. If seizure is found, hone it.
- If cylinder block or piston is replaced, match piston grade with grade number on cylinder block lower surface.
3. Measure piston skirt diameter.
Piston diameter "A"
Measuring point "a" (Distance from the bottom): 9.9 mm (0.390 inch)
4. Check that piston-to-bore clearance is within specification.
Piston-to-bore clearance = cylinder bore measurement "B" - Piston diameter "A": 0.015 - 0.035 mm (0.0006 - 0.0014 inch)
5. Determine piston oversize according to amount of cylinder wear.
Oversize pistons are available for service. Piston
6. Cylinder bore size is determined by adding piston-to-bore clearance to piston diameter "A".
Rebored size calculation: D = A + B - C where,
D: Bored diameter
A: Piston diameter as measured
B: Piston-to-bore clearance
C: Honing allowance 0.02 mm (0.0008 inch)
7. Install main bearing caps and tighten bolts to the specified torque. This will prevent distortion of cylinder bores.
8. Cut cylinder bores.
- When any cylinder needs boring, all other cylinders must also be bored.
- Do not cut too much out of cylinder bore at a time. Cut only 0.05 mm (0.0020 inch) or so at a time.
9. Hone cylinders to obtain specified piston-to-bore clearance.
10. Measure finished cylinder bore for out-of-round and taper.
- Measurement should be done after cylinder bore cools down.
Crankshaft
1. Check crankshaft main and pin journals for score, wear or cracks.
2. With a micrometer, measure journals for taper and out-of-round
Out-of-round (X - Y): Less than 0.002 mm (0.0001 inch)
Taper (A - B): Less than 0.003 mm (0.0001 inch)
3. Measure crankshaft runout.
Runout (Total indicator reading): Less than 0.04 mm (0.0016 inch)
Bearing Clearance
- Use Method A or Method B. Method A is preferred because it is more accurate.
Method A (Using bore gauge and micrometer)
Main bearing
1. Set main bearings in their proper positions on cylinder block and main bearing cap.
2. Install main bearing cap to cylinder block.
Tighten all bolts in correct order in two or three stages. Refer to Assembly, Crankshaft.
3. Measure inner diameter "A" of each main bearing.
4. Measure outer diameter "Dm" of each main journal in crankshaft.
5. Calculate main bearing clearance.
Main bearing clearance = A - Dm
Standard: 0.018 - 0.042 mm (0.0007 - 0.0017 inch)
Limit: 0.1 mm (0.004 inch)
If it exceeds the limit, replace bearing.
If clearance cannot be adjusted within standard of any bearing, grind crankshaft journal and use undersized bearing.
When grinding crank pin and crank journal:
- Grind until clearance is within specified standard bearing clearance.
- Fillets should be finished as shown in the figure. R: 2.3 - 2.5 mm (0.091 - 0.098 inch)
Refer to specifications for standard bearing clearance and available spare parts. Refer to Crankshaft, Engine; Specifications.
6. If the crankshaft is replaced, select thickness of main bearings as follows:
a. Grade number of each cylinder block main journal is punched on the respective cylinder block. These numbers are punched in either Arabic or Roman numerals.
b. Grade number of each crankshaft main journal is punched on the respective crankshaft. These numbers are punched in either Arabic or Roman numerals.
c. Select main bearing with suitable thickness according to the following table.
Main bearing grade color:
For example:
Cylinder block main journal grade number: 1
Crankshaft main journal grade number: 2
Main bearing grade number = 1 + 2 = Yellow
Connecting rod bearing (Big end)
1. Install connecting rod bearing to connecting rod and cap.
2. Install connecting rod cap to connecting rod.
Tighten bolts to the specified torque.
3. Measure inner diameter "C" of each bearing.
4. Measure outer diameter "Dp" of each crankshaft pin journal.
5. Calculate connecting rod bearing clearance.
Connecting rod bearing clearance = C - Dp
Standard: 0.014 - 0.039 mm (0.0006 - 0.0015 inch)
Limit: 0.1 mm (0.004 inch)
If it exceeds the limit, replace bearing.
If clearance cannot be adjusted using any standard bearing grade, grind crankshaft journal and use undersized bearing. Refer to step 5, under Main Bearing.
- If a new bearing, crankshaft or connecting rod is replaced, select connecting rod bearing according to the following table.
Connecting rod bearing grade number:
These numbers are punched in either Arabic or Roman numerals.
Method B (Using Plastigage)
CAUTION:
- Do not turn crankshaft or connecting rod while Plastigage is being inserted.
- If incorrect bearing clearance exists, use a thicker or undersized main bearing to ensure specified clearance.
Connecting Rod Bushing Clearance (Small end)
1. Measure inner diameter "C" of bushing.
2. Measure outer diameter "Dp" of piston pin.
3. Calculate connecting rod bushing clearance.
Connecting rod bushing clearance = C - Dp
Standard: 0.005 - 0.017 mm (0.0002 - 0.0007 inch)
Limit: 0.023 mm (0.0009 inch)
If it exceeds the limit, replace connecting rod assembly or connecting rod bushing and/or piston pin.
Replacement Of Connecting Rod Bushing (Small end)
1. Drive in small end bushing until it is flush with end surface of rod.
Be sure to align the oil holes.
2. Ream the bushing so that clearance with piston pin is within specification.
Clearance between connecting rod bushing and piston pin: 0.005 - 0.017 mm (0.0002 - 0.0007 inch)
Flywheel/Driveplate Runout
Runout (Total indicator reading):
Flywheel (M/T models)
Less than 0.15 mm (0.0059 inch)
Drive plate (A/T models)
Less than 0.2 mm (0.008 inch)
Measuring points: Approximately 115 mm (4.53 inch) from crankshaft center
CAUTION:
- Do not allow any magnetic materials to contact the ring gear teeth and rear plate.
- Do not resurface flywheel. Replace as necessary.
Assembly
CAUTION:
- When installing sliding parts such as bearings and pistons, apply engine oil on the sliding surfaces.
- Place removed parts, such as bearings and bearing caps, in their proper order and direction.
- When installing connecting rod nuts and main bearing cap bolts, apply new engine oil to threads and seating surfaces.
- Do not allow any magnetic materials to contact the ring gear, teeth of flywheel or drive plate, and rear plate.
Piston
1. Install new snap ring on one side of piston pin hole.
2. Heat piston to 60 to 70°C (140 to 158°F) and assemble piston, piston pin, connecting rod and new snap ring.
- Align the direction of piston and connecting rod.
- Numbers stamped on connecting rod and cap correspond to each cylinder.
- After assembly, make sure connecting rod swings smoothly.
3. Set piston rings as shown.
CAUTION:
- When piston rings are not replaced, make sure that piston rings are mounted in their original position.
- Install new piston rings either side up if there is no punch mark.
- Align piston rings so that end gaps are positioned as shown.
Crankshaft
1. Set main bearings in their proper positions on cylinder block and main bearing cap.
- Confirm that correct main bearings are selected by using Method A or Method B. Refer to Inspection, Bearing Clearance.
- Apply new engine oil to bearing surfaces.
2. Install crankshaft and main bearing caps and tighten bolts to the specified torque.
- Apply new engine oil to the bolt thread and seat surface.
- Prior, to tightening bearing cap bolts, shift crankshaft back and forth to properly seat the bearing caps.
- Tighten bearing cap bolts gradually in two or three stages. Start with center bearing and move outward as shown in figure.
- After securing bearing cap bolts, make sure crankshaft turns, smoothly by hand.
3. Measure crankshaft end play.
Crankshaft end play:
Standard 0.060 - 0.180 mm (0.0024 - 0.0071 inch)
Limit 0.3 mm (0.012 inch)
If beyond the limit, replace thrust bearings with new ones.
4. Install connecting rod bearings in connecting rods and connecting rod caps.
- Confirm that correct bearings are used.
- Install bearings so that oil hole in connecting rod aligns with oil hole of bearing.
- Apply new engine oil to bolt threads and bearing surfaces.
5. Install pistons with connecting rods.
a. Install them into corresponding cylinders with Tool.
- Make sure connecting rod does not scratch cylinder wall.
- Make sure connecting rod bolts do not scratch crankshaft pin journals.
- Arrange so that front mark on piston head faces engine.
- Apply new engine oil to piston rings and sliding surface of piston.
b. Install connecting rod caps.
Apply new engine oil to bolt threads and nut seating surfaces.
Tighten connecting rod cap nuts in the following procedure:
1. Tighten to 13.72 to 15.68 Nm (1.399 to 1.599 kg-m, 10.120 - 11.566 ft. lbs.).
2. Turn nuts to 35° to 40° degrees clockwise with an angle wrench. If an angle wrench is not available, tighten nuts to 23 to 28 Nm (2.3 to 2.9 kg-m, 17 to 21 ft. lbs.).
6. Measure connecting rod side clearance.
Connecting rod side clearance:
Standard 0.200 - 0.470 mm (0.0079 - 0.0185 inch)
Limit 0.50 mm (0.0197 inch)
If beyond the limit, replace connecting rod and/or crankshaft.
7. Install rear oil seal retainer.
a. Before installing rear oil seal retainer, remove old liquid gasket from cylinder block and retainer.
b. Apply a continuous bead of liquid gasket to rear oil seal retainer.
- Use Nissan Genuine RTV silicone sealant Part No. or equivalent.
- Apply around inner side of bolt holes.