ISUZU TF SERIES 2004 Workshop Manual

ENGINE MECHANICAL (6VE1 3.5L) 6A-57
Disassembly
1. Remove camshaft bracket fixing bolts (1).
2. Remove camshaft assembly (intake).
3. Remove camshaft assembly (Exhaust side).
4. Remove shim (4) and tappet (5).
5. Use the 5
8840
2446
0 valve spring compresso
r
and 5
8840
2547
0 valve spring compressor
adapter to remove split collar.



014RW042
6. Remove valve spring.
7. Remove valve.
8. Remove oil controller and spring lower seat.
9. Remove the valve guide using the 5
8840
2442
0
valve guide replacer.
Inspection and Repair
Valve Spring
CAUTION: Visually inspect the valve springs and
replace them if damage or abnormal wear is
evident.
1. Measure the free height of the springs. The
springs must be replaced if the free height is belo
w
the specified limit.
Standard: 44.6 mm (1.756 in)
Limit: 43.6 mm (1.717 in)





014RS004
2. Measure the valve spring squareness with a steel
square and replace the valve springs if the
measured value exceeds the specified limit.
Limit: 2 mm (0.079 in)


014RS005
3. Using a spring tester to compress the springs to
the installed height, measure the compressed
spring tension, and replace the springs if the
measured tension is below the specified limit.
At installed height: 35.0 mm (1.38 in)
Standard: 196 N (44 lb)
Limit: Less than 181 N (41 lb)

6A-58 ENGINE MECHANICAL (6VE1 3.5L)





LNW21BSH056701
Valve Guide
CAUTION: Take care not to damage the valve seat
contact surface, when removing carbon adhering to
the valve head. Carefully inspect the valve stem fo
r
scratchs or abnormal wear. If these conditions are
present, the valve and the valve guide must be
replaced as a set.
1. Measure the valve stem diameter with a
micrometer. If the valve stem diameter is less than
the specified limit, the valve and the valve guide
must be replaced as a set.
Diameter of Valve Stem
Intake
Standard: 5.977 mm




5.959 mm
(0.2353 in




0.2346 in)
Limit: 5.90 mm (0.2323 in)
Exhaust
Standard: 5.952 mm




5.970 mm
(0.2343 in




0.2350 in)
Limit: 5.90 mm (0.2323 in)





014RS007
2. Measure the inside diameter of the valve guide
with a micrometer. Subtract the measured oute
r
diameter of the valve stem from the measured
inner diameter of the valve guide. If the value
exceeds the specified limit, the valve and the valve
guide must be replaced as a set.
Inside Diameter of the Vale Guide
Inlet clearance
Standard : 0.023 mm




0.056 mm(0.0009
in




0.0002 in)
Limit : 0.20 mm (0.00787 in)
Exhaust clearance
Standard : 0.030 mm




0.063 mm(0.0012
in




0.0025 in)
Limit : 0.20 mm (0.00787 in)

ENGINE MECHANICAL (6VE1 3.5L) 6A-59
Valve Guide Replacement
1. Using Valve guide replacer: 5
8840
2442
0,
drive out the valve guide from the combustion
chamber side.


014RS008
2. Apply engine oil to the outside of the valve guide.
Using valve guide replacer 5
8840
2442
0,
drive in a new valve guide from the camshaft side,
and check the valve guide height.
Valve guide upper end height: 13.0 mm (0.5118
in)
(Measured from the cylinder head upper face)





014RW046
3. Check the clearance. If the clearance is less than
the specified value, ream the inside diameter o
f
valve guide. Using a sharp 6 mm reamer, ream the
valve guide to obtain the specified clearance.

Valve Seat
1. Measure the protrusion of the valve stem when a
new valve is installed in the cylinder head. If the
protrusion of the valve stem exceeds the limit,
replace the valve seat insert or the cylinder head
assembly.
Protrusion of valve stem
Intake
Standard: 39.32 mm (1.5480 in)
Limit: 39.47 mm (1.5539 in)
Exhaust
Standard: 39.30 mm (1.5472 in)
Limit: 39.45 mm (1.5531 in)





014RW047

6A-60 ENGINE MECHANICAL (6VE1 3.5L)
2. Measure the valve seat contact width. Make the
necessary corrections if the seat contact surface is
damaged or rough or if the contact width wea
r
exceeds the limit.
Valve seat contact width
Standard: 1.1 mm (0.0433 in)
Limit: 1.7 mm (0.0669 in)


014RS011
Contact Surface Angle on Valve Seat on
Valve
1. Measure contact surface angle on valve seat.
2. If the measured value exceeds the limit, replace
valve, valve guide and valve seat as a set.
Valve contact surface angle: 45
 


014RS012


Valve Seat Insert Correction
1. Remove the carbon from the valve seat insert
surface.
2. Use a valve cutter to minimize scratches and othe
r
rough areas. This will bring the contact width back
to the standard value. Remove only the scratches
and rough areas. Do not cut away too much. Take
care not to cut away unblemished areas of the
valve seat surface.
Valve seat angle degree: 90
 





014RW059
3. Apply abrasive compound to the valve seat insert
surface.
4. Insert the valve into the valve guide.
5. Turn the valve while lapping it to fit the valve sea
t
insert.
6. Check that the valve contact width is correct.
7. Check that the valve seat insert surface is in
contact with the entire circumference of the valve.

014RS014

ENGINE MECHANICAL (6VE1 3.5L) 6A-61
Valve Seat Insert Replacement
1. Arc weld the rod at several points. Be careful not
to damage the aluminum section.
2.
Allow the rod to cool for a few minutes. This will
cause the valve seat to shrink.
3. Strike the rod and pull it out.


014RS015
4. Carefully clean the valve seat press
fit section on
the cylinder head side.
5. Heat the press
fit section with steam or some
other means to cause expansion. Cool the valve
seat with dry ice or some other means.
6. Insert the press
fit section into the valve sea
t
horizontally.
Standard fitting interference: 0.14 mm




0.09 mm
(0.0055 in




0.0035 in)
7.
After insertion, use a seat grinder to grind finish
the seating face. Carefully note the seating angle,
the contact width, and the depression.
8. Lap the valve and the seat.

Reassembly
1. Install valve guide (1) to cylinder head. Apply
engine oil to the outside of the valve guide. Using
valve guide replacer 5
8840
2442
0, drive in a
new valve guide from the camshaft side.
2. Install oil controller (3) and spring lower seat (2).
Using oil controller replacer 5
8840
0623
0, drive
in a new oil controller.




014RW058
3. Install valve to valve guide. Before install valve
guide apply engine oil to the outside of the valve
stem.
4. Install valve spring to cylinder head. Attach the
valve spring to the lower spring seat. The painted
area of the valve spring should be facing
downward.


014RS020

6A-62 ENGINE MECHANICAL (6VE1 3.5L)
5. Install lower valve spring seat, valve spring and
upper valve spring seat then put split collars on the
upper spring seat, using the 5
8840
2446
0 valve
spring compresor and 5
8840
2547
0 valve
spring compressor adapter to install the spli
t
collars.



014RW042
6. Install tappet with shim.
7. Install camshaft assembly.
 Refer to installation procedure for Camshaft in
this manual.
Valve Clearance Adjustments
NOTE: To adjust valve clearance, apply engine oil to
the cam as well as to the adjusting shim (2) with the
cylinder head built on the cylinder block, give a fe
w
turns to the camshaft by means of timing pulley
tightening bolt, and measure valve clearance when the
nose of cam is just opposite to maximum cam lift (1) as
shown in illustration below.







014RW081
Legend
(1) Cam
(2) Shim
(3) Tappet

Valve Clearance Standard Value (cold)
Intake: 0.23 mm




0.33 mm
(0.0091 in




0.0130 in)
Exhaust: 0.25 mm




0.35 mm
(0.0098 in




0.0138 in)
Selection of Adjusting Shim
Shim to be selected = (Thickness of removed
shim) + (Valve clearance measurement
Standard
value) Based on the above formula, the best suited
shim should be selected from 41 sorts of shim
(differently thick at 0.02mm (0.0008 in) intervals from
2.40mm (0.0945 in) through 3.2mm (0.1260 in) thick).
Install the shim and check valve clearance.

ENGINE MECHANICAL (6VE1 3.5L) 6A-63
Replacement of Shim
Let the cam push down the edge of tappet by using
5
8840
2444
0 valve clearance adjusting tool and
push out the shim with a flat blade screw driver as
shown in illustrations below.





014RW082





014RW083



014RW084

6A-64 ENGINE MECHANICAL (6VE1 3.5L)
Camshaft
Camshaft and Associated Parts







014RW040
Legend
(1) Camshaft Bracket Fixing Bolt
(2) Camshaft Bracket
(3) Camshaft Assembly Intake
(4) Camshaft Assembly Exhaust
(5) Pulley Fixing Bolt

(6) Camshaft Drive Gear Pulley
(7) Retainer Fixing Bolt
(8) Retainer
(9) Camshaft Drive Gear
(10) Oil Seal

Disassembly
1. Remove fixing bolt (5) for camshaft drive gear
pulley using 5
8840
2447&
ndash;0 universal
holder.

ENGINE MECHANICAL (6VE1 3.5L) 6A-65



014RW060
2. Remove twenty fixing bolts from inlet and exhaust
camshaft bracket on one side bank, then camshaft
brackets (2).








014RW027
3. Remove camshaft assembly (3), (4).
4. Remove three fixing bolts (7) from camshaft drive
gear retainer (8), then camshaft drive gea
r
assembly.

Inspection and Repair
1. Use a micrometer to measure the cam lobe height
and uneven wear. Replace the camshaft if eithe
r
the lobe height or the uneven wear exceeds the
specified limit.
Lobe height: 44.709 mm (1.7602 in)
Uneven wear: 0.05 mm (0.0020 in)

014RW043
2. Use a micrometer to measure the diameter and
the uneven wear of the camshaft journals.
Replace the camshaft if the diameter or the
uneven wear exceeds the specified limit.
Journal Diameter
Standard: 25.972 mm




25.993 mm (1.0225
in




1.0233 in)
Limit: 25.8 mm (1.0157 in)
Uneven wear: 0.05 mm (0.0020 in)





014RS023

6A-66 ENGINE MECHANICAL (6VE1 3.5L)
3. Place the camshaft on V
blocks.
Slowly rotate the camshaft and measure the
runout with a dial indicator.
Replace the camshaft if the runout exceeds the
specified limit.
Run out
Limit: 0.1 mm (0.0039 in)






014RW044
4. Measure the camshaft journal oil clearance.
1. Measure the camshaft bracket housing inside
diameter.
NOTE: Tighten camshaft bracket (2) to specified torque
before measuring the camshaft bracket inside diameter.
Torque : 10 N
 m (1.0 kg
 m/7 lb ft)






014RW031
2. Subtract the camshaft outside diameter from the
camshaft bracket housing inside diameter.
Oil Clearance
Standard : 0.027 mm




0.078 mm(0.0011 in




0.0031
in)
Limit : 0.11 mm (0.0043 in)







014RW037
5. Replace the cylinder head and/or camshaft if the
measured oil clearance exceeds the specified
limit.
1. Carefully clean the camshaft journal, the
camshaft bracket, and the cylinder head.
2. Install camshaft assembly and camshaf
t
brackets (2), tighten twenty bolts (1) on one
side bank to the specified torque.
Torque: 10 N
 m (1.0 kg
 m/7 lb ft)






014RW031