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Engine: Crankshaft and Camshaft Components Measuring Idler Gear-to-Camshaft Gear Backlash

1. The document describes procedures for measuring backlash between gears in the engine's crankshaft and camshaft assembly, including the idler gear, crankshaft gear, and camshaft gear. 2. The process involves installing a dial indicator and rotating gears to measure clearance between them, being careful to prevent unwanted rotation of other gears. 3. Removal of gears is also described, noting that the camshaft and fuel injection pump gears should only be removed if damaged to avoid improper timing.

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107 views2 pages

Engine: Crankshaft and Camshaft Components Measuring Idler Gear-to-Camshaft Gear Backlash

1. The document describes procedures for measuring backlash between gears in the engine's crankshaft and camshaft assembly, including the idler gear, crankshaft gear, and camshaft gear. 2. The process involves installing a dial indicator and rotating gears to measure clearance between them, being careful to prevent unwanted rotation of other gears. 3. Removal of gears is also described, noting that the camshaft and fuel injection pump gears should only be removed if damaged to avoid improper timing.

Uploaded by

carlos javier
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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TNV_DI_SM_A4.

book 74 ページ ２００７年１２月６日　木曜日　午前９時２３分

ENGINE Crankshaft and Camshaft Components

Measuring Idler Gear-to-Camshaft Gear


(1)
(2) Backlash
1. Drive a small wooden wedge between the
crankshaft gear and idler gear to prevent the
B B
C C idler gear from rotating.

(7)
A 2. Install the dial indicator to read the camshaft
A
(3) gear backlash. Rotate the camshaft drive gear
against the idler gear to measure the backlash.
(6) (4)
(5) 0001709A
Record the measurement.
3. Check the idler gear-to-fuel injection pump
1 – Fuel Injection Pump Drive Gear drive gear backlash in the same manner as the
2 – Camshaft Drive Gear camshaft drive gear. Record the measurement.
3 – Auxiliary Drive Gear (Optional)
4 – Crankshaft Drive Gear Removal of Timing Gears
5 – Direction of Rotation 1. Remove the bolts from the idler gear shaft
6 – Oil Pump Drive Gear (4TNV94L - 4TNV106) (Figure 6-91, (1)). Remove the idler gear shaft,
7 – Idler Gear idler gear (Figure 6-91, (2)) and bushing
Figure 6-89 (Figure 6-91, (3)).

Note: 3TNV82A - 4TNV88: The oil pump is


driven directly by flats on the crankshaft
drive gear hub.

Measuring Idler Gear-to-Crankshaft Gear


Backlash (2)

1. Install a dial indicator as shown in Figure 6-90. (3)


(1)

0001728A

Figure 6-91
2. Do not remove the crankshaft gear unless it is
damaged and requires replacement. If the gear
must be removed, remove it using a gear puller.
3. Removal of the camshaft gear requires the
0002086
camshaft be removed and placed in a press. Do
not remove the camshaft gear unless it or the
Figure 6-90 camshaft is damaged and requires
2. Rotate the idler gear back and forth to check replacement. See Removal of Camshaft on
the idler gear-to-crankshaft gear backlash. The page 6-76.
total indicator reading is the backlash. Record
the measurement.

6-74 TNV DI Service Manual


TNV_DI_SM_A4.book 75 ページ ２００７年１２月６日　木曜日　午前９時２３分

Crankshaft and Camshaft Components ENGINE

CAUTION
Do not loosen or remove the four bolts
retaining the fuel injection pump drive
gear to the fuel injection pump hub. Do
not disassemble the fuel injection pump
drive gear from the hub. Correct fuel
injection timing will be very difficult or
impossible to achieve.
0000031en

4. Do not remove the fuel injection pump drive


gear unless absolutely necessary to avoid
damage to the gear or pump. Do not loosen or
remove the four bolts (Figure 6-92, (3))
retaining the pump drive gear to the hub. Only
remove the nut (Figure 6-92, (1)) and washer
(1)
(Figure 6-92, (2)), leaving the hub attached to
the gear. Remove the pump drive gear and hub
as an assembly using a gear puller.

0001695A

Figure 6-93

(3)

(1)

(2)
0000162A

Figure 6-92

Removal of Oil Pan


1. Invert the engine (oil pan up) on the engine
stand.
2. Remove the oil pan (Figure 6-93, (1)).

TNV DI Service Manual 6-75

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