Lesson 3: Drive Axle & Brake System | Automotive Workshop

VIETNAM NATIONAL UNIVERSITY – HCM CITY FACULTY OF TRANSPORTATION ENGINEERING

Ho Chi Minh City University of Technology Department of Automotive Engineering
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AUTOMOTIVE WORKSHOP

Lesson 3: Drive Axle & Brake System

Purposes:
 Systematize knowledge of structure of drive axle and brake system
 Instruct the assembly-disassembly procedure of drive axle and brake system
 Instruct using tools and equipments

Expected outcomes of the lesson:

Upon completion of this lesson, the student will be able to
 assemble and disassemble drive axle and brake system properly (L01)
 cooperate with team members to fulfill practice tasks (L02)
 systematize the procedure, present and explain the practice data (L03)
 use tools and equipments properly (L04)
 comprehend safety regulations in automotive workshop (L05)

– HCMUT/2021 –

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

CONTENT

1. PURPOSE AND REQUIREMENT...................................................................................... 3

1.1. Purpose ............................................................................................................................. 3
1.2. Requirement...................................................................................................................... 3
2. BASIS OF THEORY ............................................................................................................. 3
2.1. Structure of Drive Axle .................................................................................................... 3
2.2. Structure of Brake System ................................................................................................ 4
3. PRACTICE PREPARATION .............................................................................................. 5
3.1. Practice apparatus ............................................................................................................. 5
3.2. Practice tools..................................................................................................................... 6
4. DISASSEMBLY PROCEDURE........................................................................................... 8
4.1. Before disassembly ........................................................................................................... 8
4.2. Brake system disassembly procedure ............................................................................... 8
4.2.1. Diagram of brake system disassembly procedure ..................................................... 8
4.2.2. Disassembly procedure ............................................................................................. 9
4.2.3. Check and measure basic parameters of brake system ........................................... 12
4.3. Drive axle disassembly procedure .................................................................................. 13
4.3.1. Diagram of drive axle disassembly procedure ........................................................ 13
4.3.2. Disassembly procedure ........................................................................................... 13
4.3.3. Check and measure basic parameters of final drive and differential ...................... 17
5. ASSEMBLY PROCEDURE ............................................................................................... 18
5.1. Drive axle assembly procedure....................................................................................... 18
5.1.1. Diagram of drive axle assembly procedure ............................................................. 18
5.1.2. Assembly procedure ................................................................................................ 18
5.2. Brake system assembly procedure .................................................................................. 19
5.2.1. Diagram of brake system assembly procedure ........................................................ 19
5.2.2. Assembly procedure ................................................................................................ 19
6. PRACTICE REPORT ......................................................................................................... 20

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

1. PURPOSE AND REQUIREMENT

1.1. Purpose
Provide for student knowledge of:
- Structure of Drive Axle and Brake System.
- Principle of Operation of Final Drive, Differential, and Brake System.
- Specifications of Final Drive, Differential, and Brake System.
- Working parameters of Final Drive, Differential, and Brake System.
- Disassembly and Reassembly Procedures.
1.2. Requirement

Thoroughly comprehend the knowledge of previous courses:

- Automotive Mechanics
- Vehicle Dynamics
- Tolerance and Measurement Techniques

2. BASIS OF THEORY
2.1. Structure of Drive Axle

Fig. 3.1: Structure of drive axle

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Fig. 3.2: Structure of final drive and differential

2.2. Structure of Brake System

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Fig. 3.3: Structure of Brake Mechanism

3. PRACTICE PREPARATION
3.1. Practice apparatus

Fig. 3.4: SYM T880 Rear Axle

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Table 3.1: Apparatus Specifications

No. Specification Value Note
1 Manufacturer SYM Taiwan
2 Type
3 Gear ratio
4 Lubricating oil viscosity
5 Volume of lubricating oil
3.2. Practice tools
 Common tools

Fig. 3.5: Common tools

 SSTs
Table 3.2: SSTs
No. Tool Illustration

Torque wrench
1

2-jaw and 3-jaw gear puller

2

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

3 Sliding hammer

4 Puller set

 Measuring equipments

Table 3.3: Measuring equipments

No. Equipment Illustration

1 Caliper

2 Micrometer

 Practice supplies

Table 3.4. Practice supplies

No. Name Quantity

1 Rag 0,2kg/group

2 Tray 2 trays/group

3 Gasoline/diesel/oil 2/3/1 liters

4 Gasket sealant 2 tubes/group

5 Oil dispenser 1 bottle/group

6 RP7 lubricant 1 bottle/group

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

7 Gasket scraper 1 set/ group

8 Brush 1 piece/group

9 Pin punch set 2 sets/ 3 groups

10 Wood 1 set/ group

11 Tube 1 set/ group

12 Correction pen 1 piece/group

13 Glove 3 pairs/group

14 Grease 100gr/group

15 Sandpaper 5 sheets/group

16 Circlip plier 2 units/group

17 Slotted screwdriver 1 unit/group

18 Axle oil 1 bottle/group

4. DISASSEMBLY PROCEDURE
4.1. Before disassembly
 Check the practice tools and equipments.
 Clean up the practice area and apparatus.
 Visually check the apparatus.

4.2. Brake system disassembly procedure

4.2.1. Diagram of brake system disassembly procedure

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

Remove the Remove the shoe

Drain brake fluid
brake drum hold down spring

Remove the shoe

return spring

Disassemble the Remove the wheel Remove the

wheel cylinder cylinder from the brake shoes
backing plate

Fig. 3.6: Diagram of brake system disassembly procedure

4.2.2. Disassembly procedure

*Note: Mark X in the box after completing each step

 Drain brake fluid

Use wrench to loosen the bleeder screw.
Drain brake fluid.

Fig. 3.7: Bleeder screw

 Remove the brake drum
Use wrench to loosen brake drum’s nuts.
Pull the drum out of the axle.
*Note: Use a screwdriver and rubber mallet or a brake drum puller to take the
drum out of the axle if pulling brake drum by hand is unable.

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Fig. 3.8: Brake drum

 Remove the shoe hold down springs
Use the pliers to push and rotate the shoe hold down pins 90 degrees
Remove the shoe hold dow spring clips.

Fig. 3.9: Shoe hold down spring

 Remove the return springs
Use the pliers to remove the return springs.

Fig. 3.10: Return springs

 Remove the brake shoes.
Remove the brake shoes
Remove the parking lever.

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

Fig. 3.11: Brake shoes and parking lever

*Note: Mark on the leading and trailing shoes. Do not install these shoes
incorrectly.

 Remove the wheel cylinders from the backing plates.

Use wrench to loosen 2 attaching bolts between backing plate and wheel
cylinder.
Remove the wheel cylinder from the backing plate.

Fig. 3.12: Remove the wheel cylinder

 Disassemble the wheel cylinder.
Disassemble the wheel cylinder.

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Fig. 3.13: Disassemble the wheel cylinder

*Note: Arrange all components in the disassembly order
 List all components in the wheel cylinder in the below table.

Table 3.5. Wheel cylinder’s components

No. Component Qty. No. Component Qty.
1 6
2 7
3 8
4 9
5 10
4.2.3. Check and measure basic parameters of brake system

Table 3.6. Left brake mechanism parameters

No. Parameter Unit Value

1 Inner diameter of Brake Drum mm
2 Outer diameter of Brake Drum mm
3 Width of leading shoe mm
4 Thickness of leading shoe mm
5 Width of trailing shoe mm
6 Thickness of trailing shoe mm
7 Brake shoe span angle degree

Table 3.7: Right brake mechanism parameters

No. Parameter Unit Value

1 Inner diameter of Brake Drum mm
2 Outer diameter of Brake Drum mm
3 Width of leading shoe mm
4 Thickness of leading shoe mm
5 Width of trailing shoe mm
6 Thickness of trailing shoe mm
7 Brake shoe span angle degree

Table 3.8: Wheel cylinder parameters

No. Parameter Unit Value

1 Inner diameter of Wheel Cylinder mm

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

4.3. Drive axle disassembly procedure

4.3.1. Diagram of drive axle disassembly procedure

Remove the Remove the

Drain oil brake drums and carrier housing
half shafts

Remove the side Disassemble the Remove axle

bearings pinion gear flange’s nut

Remove the lock Remove the ring Remove

pin gear differential
assembly

Fig. 3.14: Diagram of (rear) drive axle disassembly procedure

4.3.2. Disassembly procedure

*Note: Mark X in the box after completing each step

 Drain oil
Use wrench to loosen drain plug at the bottom of rear axle.
Drain oil.

Fig. 3.15: Drain plug

 Remove the brake drums and half shafts
Remove the brake drums.
Loosen 4 backing plate bolts.
Use slide hammer to remove the half shafts.

*Note: Mark on the brake drums and half shafts.

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

Fig. 3.16: Remove the brake drum

Fig. 3.17: Remove backing plate’s bolts

Fig. 3.18: Remove half shaft

 Remove the carrier housing.
Use wrench to loosen bolts at the carrier housing.
Pull the carrier out of the axle.

Fig. 3.19: Remove carrier housing’s bolts

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Fig. 3.20: Differential assembly

 Remove the axle flange’s nut.
Remove nut

Fig. 3.21: Flange’s nut

 Remove the differential assembly
Loosen the differential cap bolts.
Remove the differential assembly.

Fig. 3.22: Differential cap bolts

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Fig. 3.23: Remove the differential assembly

*Note: Pay attention to non-interchangeable components.
 Remove the ring gear.
Loosen the ring gear bolts.
Remove the ring gear.

Fig. 3.24: Remove the ring gear

 Remove the lock pin
Use hammer to remove the lock pin.

Fig. 3.25: Remove the lock pin

 Remove the side bearing.
Use the 3-jaw puller to remove the side bearings.

*Note: Do not damage the side bearings during removing

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Fig. 3.26: Remove side bearing

 Disassemble the pinion gear
Disassemble the pinion gear.

Fig. 3.27: Pinion gear

*Note: Pay attention to small components such as washers. Arrange all
components in the disassembly order.

4.3.3. Check and measure basic parameters of final drive and differential
Table 3.9: Final drive parameters

No. Parameter Unit Value

1 Number of teeth of ring gear
2 Number of teeth of pinion gear
3 Final drive ratio
4 Outer diameter of front pinion bearing mm
5 Inner diameter of front pinion bearing mm
6 Outer diameter of rear pinion bearing mm
7 Inner diameter of rear pinion bearing mm

Table 3.10: Differential parameters

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No. Parameter Unit Value

1 Number of teeth of spider gear
2 Number of teeth of side gear
3 Outer diameter of side bearing mm
4 Inner diameter of side bearing mm

Table 3.11: Half shaft parameters

No. Parameter Unit Value

1 Diameter of half shaft’s shank mm
2 Outer diameter of half shaft bearing mm
3 Inner diameter of half shaft bearing mm
5. ASSEMBLY PROCEDURE
5.1. Drive axle assembly procedure
5.1.1. Diagram of drive axle assembly procedure

Install the brake Install the carrier

Fill oil drums and half housing
shafts

Install the side Assemble the Install the

bearings pinion gear flange’s nut

Install the lock pin Install the ring Install

gear differential
assembly

Fig. 3.28: Diagram of (rear) drive axle assembly procedure

5.1.2. Assembly procedure
Rear axle assembly procedure reverses the procedure of disassembly. Pay
attention to the following steps to make sure that axle works properly, avoids damages
and failures.
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5.2. Brake system assembly procedure
5.2.1. Diagram of brake system assembly procedure

Install the shoe

Install the brake
Fill brake fluid hold down
drum
springs

Install the shoe

return springs

Assembly the Install the wheel Install the brake

wheel cylinder cylinder on the shoes
backing plate

Fig. 3.29: Diagram of brake system assembly procedure

5.2.2. Assembly procedure
Brake system assembly procedure reverses the procedure of disassembly. Pay
attention to the following steps to make sure that the brake system works properly, avoids
damages and failures.
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6. PRACTICE REPORT

Each group of students submits a report as the below template

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

VIETNAM NATIONAL UNIVERSITY – HCM CITY FACULTY OF TRANSPORTATION ENGINEERING

Ho Chi Minh City University of Technology Department of Automotive Engineering
---------- ----------

AUTOMOTIVE WORKSHOP

PRACTICE REPORT

Lesson 3: Drive Axle & Brake System

Instructor: ………………………………………………

Student:

Name: ……………………………………

ID: ………………………………………

Class: …………………………………………

Group: ………………………………………

HCMUT - …/ …/ 20…

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TEAM MEMBER ASSIGNMENT

No. Name ID Assignment Section Grade

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

7. PRACTICE DATA
7.1. Apparatus Specifications
Table 1: SYM T880 Rear Axle Specifications

No. Specification Value Note

1 Manufacturer SYM Taiwan

2 Type

3 Final drive ratio

4 Lubricating oil viscosity

5 Volume of lubricating oil

7.2. Brake System Specifications

Fig. 1: Structure of wheel cylinder

Table 2: Wheel cylinder’s component

No. Component Qty. No. Component Qty.

1 6

2 7

3 8

4 9

5 10

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Lesson 3: Drive Axle & Brake System | Automotive Workshop

Table 3: Left brake mechanism parameters

No. Parameter Unit Value

1 Inner diameter of Brake Drum mm

2 Outer diameter of Brake Drum mm

3 Width of leading shoe mm

4 Thickness of leading shoe mm

5 Width of trailing shoe mm

6 Thickness of trailing shoe mm

7 Brake shoe span angle degree

Table 4: Right brake mechanism parameters

No. Parameter Unit Value

1 Inner diameter of Brake Drum mm

2 Outer diameter of Brake Drum mm

3 Width of leading shoe mm

4 Thickness of leading shoe mm

5 Width of trailing shoe mm

6 Thickness of trailing shoe mm

7 Brake shoe span angle degree

Table 5: Wheel cylinder parameters

No. Parameter Unit Value

1 Inner diameter of Wheel Cylinder mm

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7.3. Drive Axle Specifications

Table 6: Final drive parameters

No. Parameter Unit Value

1 Number of teeth of ring gear

2 Number of teeth of pinion gear

3 Final drive ratio

4 Outer diameter of front pinion bearing mm

5 Inner diameter of front pinion bearing mm

6 Outer diameter of rear pinion bearing mm

7 Inner diameter of rear pinion bearing mm

Table 7: Differential parameters

No. Parameter Unit Value

1 Number of teeth of spider gear

2 Number of teeth of side gear

3 Outer diameter of side bearing mm

4 Inner diameter of side bearing mm

Table 8: Half shaft parameters

No. Parameter Unit Value

1 Diameter of half shaft’s shank mm

2 Outer diameter of half shaft bearing mm

3 Inner diameter of half shaft bearing mm

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8. ASSEMBLY-DISASSEMBLY PROCEDURE
 Student can refer to the assembly-disassembly procedure in this material.
 Requirements
- Present the assembly-disassembly procedure in detail by illustration and description
- Bonus for presenting the assembly-disassembly procedure by video

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