Cylinder Block: Inspection

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CLEAN CYLINDER BLOCK
1. Using a gasket scraper, remove all the gasket material from the top surface of the cylinder block.
2. Using a soft brush and solvent, thoroughly clean the cylinder block.
Fig 1: Removing Gasket Material From Cylinder Block
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT CYLINDER BLOCK

Inspect for flatness.
Using a precision straight edge and a feeler gauge, measure the surfaces contacting the cylinder head and main bearing cap for a warp.

Maximum warpage: 0.07 mm (0.0028 in.)

If the warp is greater than the maximum, replace the cylinder block.

Fig 2: Inspecting Cylinder Block
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Visually check the cylinder for vertical scratches.
If deep scratches are found, rebore all the 8 cylinders and replace all the 8 pistons (See REPLACEMENT ). If necessary, replace the cylinder block.

Fig 3: Checking Cylinder For Vertical Scratches
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Inspect the cylinder bore diameter.

HINT:

There are 3 sizes of the standard cylinder bore diameter, marked "1", "2" and "3" accordingly. The mark is stamped on the top of the cylinder block.

Fig 4: Locating Cylinder Bore Diameter Marks

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using a cylinder gauge, measure the cylinder bore diameter at positions A, B and C in the thrust and axial directions.

Standard diameter:

STANDARD DIAMETER REFERENCE

STD Mark "1"	94.002 - 94.010 mm (3.7009 - 3.7012 in.)
Mark "2"	94.010 - 94.023 mm (3.7012 - 3.7017 in.)
Mark "3"	94.023 - 94.031 mm (3.7017 - 3.7020 in.)

Maximum diameter: 94.23 mm (3.7098 in.)

MAXIMUM DIAMETER REFERENCE

STD	94.231 mm (3.7099 in.)
O/S 0.50	94.731 mm (3.7296 in.)

If the diameter is greater than the maximum, rebore all the 8 cylinders and replace all the 8 pistons (See REPLACEMENT ). If necessary, replace the cylinder block.

Fig 5: Measuring Cylinder Bore Diameter

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Remove the cylinder ridge.
If the wear is less than 0.2 mm (0.008 in.), using a ridge reamer, grind the top of the cylinder.

Fig 6: Removing Cylinder Ridge
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Using vernier calipers, measure the thread outside diameter of the main bearing cap bolt.
Standard diameter:

10.760 - 10.970 mm (0.4236 - 0.4319 in.)

Minimum diameter: 10.40 mm (0.4094 in.)

If the diameter is less than the minimum, replace the cap bolt.

Fig 7: Measuring Thread Outside Diameter Of Main Bearing Cap Bolt

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CLEAN PISTON
1. Using a gasket scraper, remove the carbon from the piston top.
  
  Fig 8: Removing Carbon From Piston Top
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a groove cleaning tool or broken ring, clean the piston ring grooves.
  
  Fig 9: Cleaning Piston Ring Grooves
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using solvent and a brush, thoroughly clean the piston.
NOTE: Do not use a wire brush.

Fig 10: Cleaning Pistons
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT PISTON AND CONNECTING ROD

Inspect the piston oil clearance.

HINT:

There are 3 sizes of the standard piston diameter, marked "1", "2" and "3" accordingly. The mark is stamped on the piston top.

Using a micrometer, measure the piston diameter at right angles to the piston pin center line, 30.75 mm (1.2106 in.) from the piston head.

Piston diameter:

MAXIMUM DIAMETER REFERENCE

STD Mark "1"	93.902 - 93.912 mm (3.6969 - 3.6973 in.)
Mark "2"	93.912 - 93.920 mm (3.6973 - 3.6976 in.)
Mark "3"	93.920 - 93.930 mm (3.6976 - 3.6980 in.)
O/S 0.50	94.402 - 94.430 mm (3.7166 - 3.7177 in.)

Fig 11: Identifying Piston Markings

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the cylinder bore diameter in the thrust directions. (See step 2 above)
Subtract the piston diameter from the cylinder bore diameter.
Standard oil clearance:

0.090 - 0.111 mm (0.0035 - 0.0044 in.)

Maximum oil clearance: 0.13 mm (0.0051 in.)

If the oil clearance is greater than the maximum, replace all the 8 pistons and rebore all the 8 cylinders. (See REPLACEMENT ) If necessary, replace the cylinder block.

HINT

Use new cylinder block:

Use a piston with the same number mark as the cylinder diameter marked on the cylinder block.
The shape of the piston varies for the LH and the RH banks. The LH piston is marked as "LH" and "2L", and the RH piston as "RH" and "2R".

Fig 12: Identifying Piston Size Markings

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Inspect the piston ring groove clearance.

Using a feeler gauge, measure the clearance between new piston ring and the wall of the ring groove.

Ring groove clearance:

RING GROOVE CLEARANCE REFERENCE

No. 1	0.030 - 0.080 mm (0.0012 - 0.0031 in.)
No. 2	0.030 - 0.070 mm (0.0012 - 0.0028 in.)

If the clearance is not as specified, replace the piston.

Fig 13: Inspecting Piston Ring Groove Clearance

Inspect the piston ring end gap.

Insert the piston ring into the cylinder bore.
Using a piston, push the piston ring to a little beyond the bottom of the ring travel, 105 mm (4.13 in.) from the top of the cylinder block.

Fig 14: Inserting Piston Ring In Cylinder
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Using a feeler gauge, measure the end gap.

Standard end gap:

END GAP REFERENCE

No. 1	0.300 - 0.500 mm (0.0118 - 0.0197 in.)
No. 2	0.400 - 0.650 mm (0.0157 - 0.0256 in.)
Oil (Side rail)	0.130 - 0.480 mm (0.0051 - 0.0189 in.)

Maximum end gap:

END GAP REFERENCE

No. 1	1.10 mm (0.0433 in.)
No. 2	1.20 mm (0.0472 in.)
Oil (Side rail)	1.15 mm (0.0453 in.)

Fig 15: Measuring End Gap

If the end gap is greater than the maximum, replace the piston ring. If the end gap is greater than the maximum, even with a new piston ring, rebore all the 8 cylinders (See REPLACEMENT ) or replace the cylinder block.

Inspect the piston pin fit.
At 60°C (140°F), you should be able to push the piston pin into the piston pin hole with your thumb.

Fig 16: Inspecting Piston Pin Fit
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Using a rod aligner and the feeler gauge, check the connecting rod alignment.
1. 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.
  
  Fig 17: Checking Connecting Rod For Bend
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check for twist
  Maximum twist:
  
  0.15 mm (0.0059 in.) per 100 mm (3.94 in.)
If twist is greater than the maximum, replace the connecting rod assembly.

Fig 18: Checking Connecting Rod Twist
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect the piston pin oil clearance.
1. Using a caliper gauge, measure the inside diameter of the connecting rod bushing.
  Bushing inside diameter:
  
  22.005 - 22.014 mm (0.8663 - 0.8667 in.)
  
  Fig 19: Inspecting Piston Pin Oil Clearance
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a micrometer, measure the piston pin diameter.
  Piston pin diameter:
  
  21.997 - 22.006 mm (0.8660 - 0.8664 in.)
3. Subtract the piston pin diameter from the bushing inside diameter.
  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 the maximum, replace the bushing. If necessary, replace the piston and the piston pin as a set.

Fig 20: Measuring Piston Pin Diameter
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Using vernier calipers, measure the tension portion of the connecting rod bolt.
Standard diameter:

7.200 - 7.300 mm (0.2835 - 0.2874 in.)

Minimum diameter: 7.00 mm (0.2756 in.)

If the diameter is less than the minimum, replace the bolt.

Fig 21: Measuring Tension Portion Of Connecting Rod Bolt

INSPECT CRANKSHAFT
1. Inspect for circle runout.
  1. Place the crankshaft on V-blocks.
  2. Using a dial indicator, measure the circle runout at the center journal.
    Maximum circle runout: 0.08 mm (0.0031 in.)
  If the circle runout is greater than the maximum, replace the crankshaft.
  
  Fig 22: Inspecting Crankshaft Runout
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Inspect the main journals and the crank pins.
  1. Using a micrometer, measure the diameter of each main journal and crank pin.
    Main journal diameter:
    
    66.988 - 67.000 mm (2.6373 - 2.6378 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 DISASSEMBLY ). If necessary, replace the crankshaft.
  2. Check each main journal and crank pin for taper and out-of-round as shown.
    Maximum taper and out-of-round:
    
    0.02 mm (0.0008 in.)
If the taper and out-of-round is greater than the maximum, replace the crankshaft.

Fig 23: Inspecting Main Journals And Crank Pins
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002