Clutch system HD120

The clutch proper transmits power from the engine to the transmission and performs the following functions when the clutch pedal is When the clutch pedal is depressed, the power cylinder

GENERAL CH - 2 SPECIFICATIONS CH - 5 SERVICE STANDARDS CH - 6 SPECIAL TOOLS CH - 9 SERVICE PROCEDURE CH - 9 TROUBLESHOOTING CH-30

Clutch housing

GENERAL

The clutch system consists of a clutch proper and control The

clutch proper transmits power from the engine to the transmission

and performs the following functions when the clutch pedal is

When the clutch pedal is depressed, the power cylinder (or clutch

booster) is operated by the hydraulic pressure from the clutch

master cylinder This causes the release bearing to push the

release lever via the clutch release fork and fork shaft The release

lever, operating on a force being applied with the support lever pin

as the fulcrum, compresses the pressure spring As a result, the

pressure plate is pulled back, cutting off power from the engine

When the clutch pedal is released, the clutch disc is compressed

against the flywheel by the pressure spring force, thus transmitting

engine power to the transmission

Release lever plate

Flywheel Clutch disc

Pressure plate Pressure spring

Release fork shaft

Release fork

Release bearing Release lever Support lever Clutch cover

CH-3CLUTCH CONTROL

The clutch pedal mechanism is the pendant type

When the pedal is depressed, the push rod is forced down into the

master cylinder, causing pressurized fluid to move the power cylinder

(or clutch booster)

The power cylinder (or clutch booster) doubles the hydraulic pressure

which moves the clutch release bearing, thereby operating the

clutch proper

<Vehicle with power cylinder>

21AR0846

Brake fluid reservoir tank

Clutch master cylinder Clutch pedal Power cylinder

Power coupled Power uncoupled

GENERAL

CLUTCH MASTER CYLINDER

21AR0801

21AR0802

Supply valve spring

Supply valve stopper

Supply valve Supply valve

spring Return spring

Cylinder

1 When clutch pedal is depressed

As the push rod pushes the piston, the supply valve is moved by

the tension of supply valve spring, thus closing the gap

As the piston is pushed further, the pressure in the cylinder is

increased and is transmitted to the power cylinder (or clutch

booster)

2 When clutch pedal is released

The pressure built up in the cylinder, together with the tension

of the return spring, forces the piston back causing the supply

valve rod to come into contact with the supply valve stopper

Then, the supply valve is opened to release fluid, thus eliminating

hydraulic pressure

Supply valve Piston

Supply valve

Clutch pedal maximum stroke

Master cylinder Diameter x stroke

Clutch power cylinder Diameter x stroke

Hydraulic cylinder Diameter x stroke

Relay valve piston Diameter x stroke

SPECIFICATIONS

Push typeStrap driveSingle dry plateNon asbestos

350 x 220 (Low) / 380 x 240 (High)

Coil spring typeHydraulic control (Air pressure assist)

21020.64 x 35

105 x 6619.8 x 66

0.2 1.50.5

212810.50.3

1.8 to 2.40.5 or less1.1 or less1.0 or less0.06 to 0.210.07 to 0.2323.6 ± 0.130.8 ± 0.110.2 to 10.250.01 to 0.16

0 to 0.15[10] 0.02 to 0.11

[10] 0.02 to 0.11

76.592.4

Service Standards Table

Depth from facing surface to rivet headClutch Clutch

disc

Nominal value(Basic diameter in [ ])Maintenance item

Unit: mm

FlatnessRunout Lateral runout

Vertical runoutHob spline play in turning direction

Clearance between release lever pin andpressure plate bushing

Strap plate to bolt clearance

Vehicle withpower cylinderReturn spring

AdjustReplace

Replace

ReplaceReplace

Replace bushing

Replace bushing

Replace

Replace

79

58 N (5.9 kgf)/55192.3 N (0.23 kgf)/1315.5

10 N (1.06 kgf)/10

Return spring Free lengthCylinder to piston clearance

Piston to cylinder clearance

94[15.87]

0.03 to 0.10[19.05]

0.04 to 0.12584

69 N (7 kgf)/55212.6 N (0.27 kgf)/

1317

12 N (1.25 kgf)/10[16] 0.04 to 0.10

[22.22] 0.01 to 0

06[19.05] 0.01 to 0

06[70] 0.20 to 0.75

-Replace

Nominal value(Basic diameter in [ ])

Clutch master

cylinder

Free lengthLoad/installed lengthFree length

Load/installed length

Free lengthLoad/installed length

Power piston to cylinder shell clearance

Power cylinder push rod bend

Replace if excessivelyworn or damagedReplace

Tightening Torque Table

Clutch

booster

Screw sizeO.D x pitch(mm)M10 x 1.5M10 x 1.25M10 x 1.25M6 x 1.0M8 x 1.25M12 x 1.25M12 x 1.5M10 x 1.25M12 x 1.5M5 x 0.5M10 x 1.25M10 x 1.25M22 x 1.5-PT1/4M14 x 1.5M8 x 1.25-M32 x 1.5M24 x 2M6 x 1.5M10 x 1.5M16 x 2

M8 x 1.25M8 x 1.25

38 to 58 (3.9 to 5.9)

38 to 58 (3.9 to 5.9)

15 (1.5)

25 to 34 (2.5 to 3.5)1.5 to 2.9 (0.15 to 0.3)

47 (4.8)

25 to 34 (2.5 to 3.5)1.5 to 2.9 (0.15 to 0.3)6.9 to 13 (0.7 to 1.3)9.8 to 49 (1 to 5)

20 to 29 (2 to 3)

15 to 20 (1.5 to 2)7.8 to 9.8 (0.8 to 1.0)

29 to 39 (3 to 4)

29 to 39 (3 to 4)3.9 to 5.9 (0.4 to 0.6)

40 (4.1)

190 (19.2)

9.8 to 15 (1.0 to 1.5)

21 (2.1)

Pressure plate and lever assembly mounting bolt

Strap plate bolt

Lock plate mounting bolt

Offset bolt

Pedal shaft mounting nut

Clutch switch

Nipple

Supply valve stopper

Power cylinder mounting bolt

Air bleeder

Fitting valve

Air bleeder plug

Exhaust cover

Power piston tightening nut

Cylinder shell and end plate mounting bolt

Cylinder shell pipe bushing

Hydraulic cylinder

Connector

Valve body mounting bolt

Clutch booster mounting bolt

Clutch housing mounting bolt (to

transmission case or splitter case

Clutch housing cover mounting bolt

(b) Remove the propeller shaft.

(c) Remove the transmission

(d) Remove the pressure plate and lever assembly

When removing the pressure plate and lever assembly,

secure the pressure plate with the, Stopper Bolt and Plain

Washer

Before removing the pressure plate and lever assembly,

install the special tool, Clutch Alignment Arbor, to prevent

the clutch disc from dropping

Then, remove the clutch disc and the special tool, Clutch

Alignment Arbor, from the flywheel

(c) Inspection of release lever plate height (only when the clutch

disc is replaced)

To check the height of clutch cover and release lever plate,

use the special tool, Clutch Release Lever Aligner

NOTE:

In case the pressure plate and lever assembly has been

replaced with a new one, do not adjust the height of the

release lever plate or release lever.

21AR0811

21AR0354

Clutch Release Lever Aligner 09411-62200

21AR0187

Pilot bearing

Flywheel

Part number stamped Clutch disc

ClutchAlignment Arbor 09411-62100

32 to 49 Nm (3.3 to 5.0 kgfm)

Knock pin hole Knock pin hole

Stopper Bolt Plain Washer

2 Installation

(a) To install the clutch disc, use the special tool, Clutch

Alignment Arbor

NOTE:

Make sure of the correct installation direction of the

clutch disc: the side on which the part number is

stamped must be visible.

(b) Install the pressure plate and lever assembly, aligning the

knock pin holes with knock pin holes with knock pins on

flywheel

In case of CLUTCH, first hold the assembly using the

Stopper Bolts and Plain Washers, and then install it on the

flywheel

NOTE:

1 Before mounting the clutch, check and clean the

flywheel If defects are evident, correct or replace the

flywheel.

2 Bolts mut be tightened in several steps in diagonal

order.

3 After installation, be sure to remove the Stopper Bolt

and Plain Washer.

4 After installation, never adjust the release levers even

if their height is not the same If adjustment is to be

made, remove the clutch again and adjust.

1.5 1.8

0.5 or less 0.6 or less 1.1 or less 1.2 or less 1.0 or less 1.2 or less

13 Release lever

14 Bushing

15 Eye bolt pin

16 Release lever eye bolt

17 Bushing

18 Pressure

NOTE:

1 The clutch cover and pressure plate are plate are balanced and alignment marks should be put on

them before disassembly.

2 Do not remove the strap plate.

Disassembly and Inspection

Clutch disc

Clearance between lever pin and pressure plate bushing

Wear

Wear

14 13 12

11 10

9 8 1

2 3 4

5 16

7

15

Deformation, cracks

11 Pressure spring cap

12 Release lever pin

NV Item

Thickness Flatness Strap bolt fitting hole Strap plate

to strap bolt clearance

21 0.2 10.5 0.3

L 76.5

835N (85 kgf) / 49.1 2.9 or less

NV Item

Flatness Load/

installed length Squareness

710N (72.3 kgf)/

-49.1 4.0 L

Lock plate Support nut Strap

bolt

Strap bolt, washer

21AR0427

Lock plate Lock bolt

Eye bolt nut Clutch cover Alignment mark

Surface plate

Dial indicator

Disassembly and Inspection Procedure

1 Removal of clutch cover

(a) With the stopper bolt as installed, remove the support nut

and strap bolt

2 Inspection of clutch disc

(a) Facing wear

Measure the assembly thickness of facing and the depth

from facing surface to rivet head If the measurement is

below the limit, replace the clutch disc assembly

(b) Flatness of clutch disc

Measure flatness of the facing surface If the limit is

exceeded, correct or replace

(c) Clutch disc runout

Using the runout tester, measure the clutch disc runout If

the measurement exceeds specification, correct or replace

the clutch disc

(b) Put alignment marks on the clutch cover and pressure

plate

(c) Gradually loosen the handle of Clutch Installer to remove

the clutch cover

Pressure plate

Pressure plate

Strap bolt fittting hole

<C5>

Bushing Pressure plateRelease lever pin

SERVICE PROCEDURE

(d) Spline play in turning direction

Using a piano wire, measure the play in the turning

direction of the clutch disc boss splines and transmission

drive pinion splines If the limit is exceeded replace the

clutch disc

(3) Inspection of pressure plate

(a) Pressure plate thickness

Measure the pressure place thickness and, if it is below the

limit, replace

(b) Pressure place flatness

Measure the flatness of the pressure plate friction surface

Regrind or replace if the limit is exceeded

(c) Strap bolt fitting hole I.D

Measure the I.D or strap bolt fitting hole in the pressure

plate and, if the limit is exceeded, replace

(4) Release lever pin to bushing clearance

Measure the release lever pin O.D and bushing I.D

Replace if clearance exceeds specification

Bushing Release levereye bolt

Eye bolt pin

21AR0739

(6) Inspection of pressure spring

Measure the free length, squareness, and installed load of the

pressure spring If the measurement is below the limit, replace

(5) Support lever pin to bushing clearance

Measure the support lever pin O.D and bushing I.D and

replace if clearance exceeds specification

CH-15 Reassembly

Grease: Molybdenum disulfide base grease

(NLGI No.2) Li soap

Apply antiseizure compound

to threads and spherical surfaces.

Apply grease to release lever sliding surfaces.

Apply grease to sliding surfaces

in pressure plate and release lever, and in release lever and in release lever and

39 to 59 Nm (4 to 6 kgfm) Apply Loctite

272 or equivalent

to threads.

14 13

12 11

5

6

7 15

18

16

17

7

For parts with an encircled number, see reassembly procedure that follows.

Item No 7 is the strap plate which is nonmaintainable.

None requiredOne 1.2

Two 1.2 mm or one 2.3 mm

21AR0429

Adjusting washer Clutch cover

Pressure plate

Eye bolt nut

21AR0427

Clutch Installer MH061051

Lock bolt Lock plate

Clutch cover Pressure plate Strap bolt

Alignment mark

21AR0740

Release lever plate

Apply grease.Support lever

nut Lock bolt

63±0.5 Release lever

9.2 (clutch disc thickness when compressed)

Reassembly Procedure

1 Whenever the pressure plate friction surface is corrected,

insert adjusting washers of thickness equivalent to correction

amount

2 Installation of clutch cover

To install the clutch cover

NOTE:

Install the clutch cover and pressure plate so that the

alignment marks on them are aligned.

3 Adjustment of release lever height

To adjust the release lever height, compress the pressure

spring using the special tool, Clutch Installer, and, at the same

time, tighten or loosen the support lever nut to obtain the

specified distance between the flywheel friction surface and the

release lever plate end As the specified dimension is obtained,

tighten the lock bolt temporarily

The final adjustment of the release lever height after the

replacement of the clutch disc must be make using the special

tool, Clutch Release Lever Aligner, with the clutch mounted on

the engine flywheel

NOTE:

Adjust the release lever height only when the clutch disc is

new.

21AR0816

Clutch switch harness

Clutch hose Harness

SERVICE PROCEDURE

Clutch Pedal

Removal and installation

NOTE:

Before removing the clutch pedal, plug the oil hose and pipe

to prevent brake fluid from running out.

1 After installing the clutch pedal, add brake fluid

2 Bleed the clutch system of air

Disassembly and Inspection

6 Clutch master cylinder

Pedal shaft to bushing clearance

11 10 9

21AR0238

21AR0864

Bushing Pedal shaft

Clutch pedal

I.D.

O.D.

Inspection Procedure

1 Inspection of return spring

Using the spring tester (for tensile load), measure the load

(tensile load) when the spring is set to the installed length If it

is less than the limit, replace the spring

2 Measurement of clearance

As installed to the clutch pedal, measure the I.D of the bushing

and O.D of the pedal shaft If the clearance exceeds the limit,

replace the bushing

SERVICE PROCEDURE

Reassembly and adjustment

<Vehicles with power cylinder>

Apply grease to inner surfaces

38 to 58 Nm (3.9 to 5.9 kgfm)

Apply grease to sliding surfaces

15 Nm (1.5 kgfm)

*232

13 12

11 10 9

8 1

2 3

4 5

6

7

CH-21Clutch Master Cylinder

Disassembly and Inspection

5 Piston stop ring

6 Piston stop plate

Compressed air

I.D.

O.D.

Disassembly Procedure

When removing the piston from the cylinder, plug the nipple and

apply compressed air from the union at the end of the cylinder to

remove the piston complete

Inspection Procedure

1 Inspection of piston and cylinder

Measure the cylinder I.D and piston O.D and if the clearance

exceeds the limit, replace the assembly

Repair kit:

Piston and boot kit

1 2

3 4

5 6

7

Return spring Clutch release fork shaft

47 Nm (4.8 kgfm)

Clutch power Clevis pin cylinder

Clutch hose

21 to 31 Nm (2.1 to 3.2 kgfm)

2 Inspection of springs

Measure the free length of return spring If it is shorter than the

limit, replace the return spring

POWER CYLINDER

Removal and installation

NOTE:

Before initiating removal procedure, be sure to plug the fluid

pipes to prevent brake fluid from flowing out.

1 After installing the clutch power cylinder, add brake fluid

[Refer to Section 5.7 Replacement of Brake fluid in Clutch

System.]

2 Bleed the clutch system of air

[Refer to Section 5.8 Bleeding the Clutch System.]

Secondary cup

1.5 to 2.9 Nm (0.15 to 0.3 kgfm)

Primary cup

Apply metal rubber to sliding surfaces of cylinder and piston

10

9

8

1 2

3 4

5

6 7

CH-23 SERVICE PROCEDURE

Disassembly and Inspection

Reassembly

21AR0220

1

2 3 4 5

Assembly sequence

4 → 5

7 → 6 → 3 → 2 → 1↓

NOTE Apply assembling oil (NA 166M or equivalent) to cylinder inner surface, piston sliding surface and cup.

3 Clutch release bearing

4 Release fork set screw

5 Release fork shaft

10

9 8

1 2 3

4

5

6 7

8

Assembly sequence

5 3

10 → 8 → 6 → 4 → 2 → 1 → 11→ 7

For parts with an encircled number, refer to

Reassembly Procedure that follows.

Reassembly

Vehicles with M5S, M6S transmission <C5>

Apply grease [wheel bearing grease (NLGI No 2) Li soap] to areas between lips.

9.8 to 15 Nm (1.0 to 1.5 kgfm) Pack grease [wheel

bearing grease

(NLGI No 2) Li soap].

Pack grease [wheel bearing greae

(NLGI No 2) Li soap].

21 Nm (2.1 kgfm)

190 Nm (19.2 kgfm)

4

5 6

7

[Vehicles with M5S, M6S transmission <C6>]

5 3

10 → 8 → 6 → 4 → 2 → 1 → 11→ 7