The Implementation of D155A-2 Bulldozer Sterring Overhaul

Al Amin, Halman and Andreal Imran

Heavy Vehichle Study Program, Nunukan State Polytechnic, Jl. Ujang Dewa, Nunukan, Indonesia

Keywords

Overhaul, Steering System, Components, Bulldozer D155A - 2.

Abstract

Bulldozer is a unit that uses a track shoe or commonly called a crawler engine, where the steering system used

in this unit uses a clutch with the basic principle of a disc consisting of an inner drum and an outer drum.

When the unit is moving straight the clutch must be tightened so that the rotation can be transferred to the

final drive and when the unit is going to be rotated the clutch must be released (stretched) so that the torque

and power of the transmission are balanced. Overhaul bulldozer D155A-2 is a maintenance activity that aims

to restore the state of a unit to its original state or according to factory standards. Steering overhaul activities

include removing components from the unit, initial cleaning, component disassembly, washing, inspection,

measurement, assembly, testing. adjustment, and installation on the unit. Some components such as dist,

coupling and inner drum that are not standard must be replaced. The mechanism for steering overhaul

activities as well as checking and measuring each component of the steering brake so that it can deepen and

find out the causes of the damage contained therein and take precautions and actions if there is damage to the

steering wheel. system.

INTRODUCTION

Heavy equipment is a tool that can be used to assist

humans in doing work not only in the mining sector,

the construction of an infrastructure, but also in

plantation fields. For these matters there are some

steps need to be done (Hadi, 1992). The selection

of heavy

equipment that is not appropriate to the

conditions and

situation of the work field. It is

avoiding the rate of

losses results such as low

production, below

performance of target production,

and improper repair

losses (Rochmanhadi, 1992). the

type and number of equipment and their

descriptions

need to be identified both their function

and

applications (Septiani et al., 2019).

In term of a vehicle unit such as heavy equipment,

it cannot be separated from the steering system. This

steering system functions is to control the direction

under the driver or operator control. That why

maintenaning and repairing of the steering system

must be well maintained in order to no errors occurs

during the operation of vehicle unit. Heavy

equipment, especially bulldozers, the steering system

is usually called a steering and braking system where

the systems are interrelated (Qing, 2015). Based on

the research

conducted by Carlo Ackermann et al.

that the

combines internal steering and braking is

avoiding collisions (Ackermann et al., 2015). The

research conducted by Zhank et al.

also shows that

the combination of steering and

braking is avoiding

unexpected riders (Zhang and Wu, 2016), while

based

on the research conducted by Vivas et al.

shows that

the suspension, steering and braking is

the main

controls in advanced level control (Vivas-

Lopez et al., 2015)

When the unit is running in the straight line, the

clutch must be in the engagement position on both the

RH (right) and LH (left) clutches, so the rotation of

the transmission is transferred to the final drive to

move the sprockets. In this matter, the clutch must be

disengaged to be able to turn the unit. It is also the

rotation and power of the transmission is not passed

to any of the final drives in order to the sprockets can

be controlled. Likewise, when experiencing is

damage, an overhaul of the steering and braking

system must be carried out, then disassembly and

checking of both parts must be carried out. It needs to

be done because the components of both parts are

located in the same place. Based on these

considerations, It is necessary to do the research

regarding to an overhaul steering study on a large tool,

namely the Bulldozer D155A-2.

896

Amin, A., Halman, . and Imran, A.

The Implementation of D155A-2 Bulldozer Sterring Overhaul.

DOI: 10.5220/0010956300003260

In Proceedings of the 4th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2021), pages 896-900

ISBN: 978-989-758-615-6; ISSN: 2975-8246

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

RESEARCH METHODS

2.1 Collecting Data

Data were collected by observation, library

research, and interviews. Observations directly in the

field during the process of overhaul activities are

carried out, observations are made when needed. Data

collection by library research in this study refers to the

shop manual D155A-2 and the Standard Operational

Procedure (SOP). Meanwhile, the interview process is

carried out by interviewing directly to the mechanic

or supervisor.

The data collected is divided into 2 parts including

primary data and secondary data. Primary data

collection will be done by making some notes of

observation and documentation in the fields.

Secondary data collection was obtained from

published company data, including: (1) Machine

Condition Report (MCR); (2) Recommended Part List

(RPL); (3) Quality Assurent (QA) D155A-2; (4) Job

Sheet Schedule (JSS); and (5) Standard Operational

Procedure Overhaul and shop manual bulldozer

D155A-2.

2.2 Data Processing

The data obtained were then will be grouped based

the order of the overhaul processing. Then the

results obtained are compared with the shop manual

and SOP overhaul in order to obtain accurate results

and it could avoiding the deviation and errors.

RESULTS AND DISCUSSION

This research is divided into 3 parts such as: (1)

implementation of overhaul steering brake system; (2)

results of overhaul steering brake system; and (3)

discussion on overhaul steering brake

3.1

Implementation of

Overhaul

Steering Brake System

Carry out steering overhaul are by removing the

steering brake and then disassembly of the steering

brake. The first step is to remove the steering brake

and then to open the plug that is under the unit at the

bottom of the steering brake. The next step is to

remove the linkage from the steering and brake

pedals. It is also necessary to remove the spring assist

brake cylinder and then to remove the hoses that are

still attached. The next step is to mark the critical

points by marking the location on each component

with the RH and LH mark. Marking aim is to make

the installation process easier. The next then remove

the chord rod that is inside the steering brake cover so

that the cover is detached from the bracket, and

remove the brake booster assy. Use a rope or sling that

is physically small but strong to lift the bracket and

steering clutch assy, lift it with the help of a crane

(same RH/LH parts), then remove the steering clutch

assy and remove the bavel gear shaft assembly. Next,

pay attention to the shim on the edge of the signpost

or the right and left sides. After the removal work is

complete, close the steering case so that dirt and other

objects don't get in, and then wash all the components

of the steering brake so that the disassembly process

is easy (Figure 1).

Figure 1: Remove steering brake.

The disassembly process is carried out carefully,

which will be disassembly of the brake booster assy,

cleaning and then washing components. After that

disassembly steering clutch assy, then the critical

point is "this process must be done carefully because

the spring has a large enough strength, about 200kg

large spring, 150kg small spring". The process is

carried out carefully (Figure 2).

Figure 2: Disassembly steering brake.

The Implementation of D155A-2 Bulldozer Sterring Overhaul

897

3.2 Result of Overhaul Steering Brake

System

This process is divided into several, namely the

first

is a visual check and measurement. This section is

checked and measured carefully, referring to the QA

sheet or guided using the shop manual according to the

unit so that the results obtained are more accurate and

do not deviate from the standard. There is also a visual

check that usually looks for dents, cracks, dirt or

anything else contained in these components.

This first part is done by washing and cleaning all

components and classifying which ones use diesel,

using soapy water and only using a cloth, and wrap it

using plastic krap to wait in assembly or check and

measure first. After that visual check and measurement

on the dist and plate, then check on the visual check

and measurement on the plate, then check on the inner

drum (Figure 3).

Figure 3: Disassembly steering brake.

The second is the component assembly process.

This assembly part is done in the right way and

carefully. After performing a visual check on the

brake drum lining and seeing its age, the brake drum

lining must be replaced (Figure 4).

Figure 4: Assembly component.

The third part to do is install the bavel gear. This

process is carried out by installing the outer races

(signs) and measuring the thickness of the shims,

installing the bolt mouting outer races but not

tightening them first (RH, LH). Then set the bavel gear

in the case, then install the shaft from the right clutch

housing, insert the shaft in the center hole of the bavel

gear to the left housing, install the appropriate shim, so

that the bevel gear center. Then tighten the bolt

mounting outer races and install or tighten the bolt

mounting bavel gear by using special tools and the

same method when removing, after that clean the

steering brake housing until it is completely clean

(because the housing is where the oil is) so that the oil

is not contaminated, and also Clean the transmission

bavel gear and pinion gear for measurement. Perform

measurement acklash´on the bavel gear (Figure 5).

Figure 5: Install bever gear.

The fourth process is to install the steering brake. This

process is done by cleaning the steering brake

housing, then attaching the steering clutch assembly

to the housing. After that, the steering clutch (RH,

LH) was measured. Then install the right and left side

mounting bolts and tighten them, and also install the

bracket, brake booster assy, attach the pins, connect

the small host that is on the brake band. After that,

adjust the steering brake on the spring assist brake,

then install the steering brake cover and torque bolt,

then fill in the steering oil for testing and adjusting

(Figure 6).

Figure 6: Install steering brake.

The fifth process is testing and adjusting the steering

brake. The process carried out is running the engine

iCAST-ES 2021 - International Conference on Applied Science and Technology on Engineering Science

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and measuring the oil pressure (Figure 7). Then the

last process is replacing the filter and strainer.

Previously the filter had not been replaced due to

flashing the impurities contained in the new

components, after which the filter and strainer were

replaced after a test run (Figure 7).

Figure 7: Testing and adjusting steering brake.

3.3 Discussion

on Overhaul

Steering

Brake

Based on the results of the inspection and

measurement of the overhaul activities above, several

damaged components must be repaired or replaced.

The possibilities that cause damage to these

components must also be known, so that preventive

measures can be taken so that they can extend their

service life and minimize expenses for component

repair or replacement. These components include: (1)

the dist and plate have scratches and dents which are

most likely caused by the steering oil being

contaminated by grams from the friction of objects

that come into contact in the steering case. Even

though at the time of measurement it was still within

the standard limits, but because of these defects, the

dist and palte components had to be replaced because

it could result in not optimal steering performance; (2)

The inner drum has a fairly severe crack which is most

likely due to the unit undergoing heavy work or it

could be due to the age of use that has passed the

standard limit and must be replaced; (3) The brake

drum lining on visual inspection of the brake drum

lining already looks thin and it can also be seen from

the historical unit that the canvas has never been

replaced, so that during this overhaul, the lining must

be replaced; (4) Tooth on the bavel gear at the time of

measurement is still in good condition because the

contact points made at the time of checking are still

within the standard limits, as well as measurements on

the backlash are still within the standard limits, so that

the bavel gear can still be used; (5) the oil pressure

measurement shows that the steering and brake

pressure has been achieved, so that during operation

the unit will not experience trouble when turning and

will not be held back when the clutch and brake work.

Because when the pressure on the clutch and brake is

not reached, it can cause a malfunction in the steering

system.

CONCLUSIONS

The results showed that the overhaul process must

in accordance with the Standard Operating

Procedure (SOP) so that the mechanism can be

controlled and run properly, always referring to the

shop manual as a guide for accuracy in every overhaul

steering process. The steering overhaul work includes

remove, namely removing the steering and brake

components from the unit, prewashing, disassembly,

namely dismantling steering and brake components,

washing, inspection and measurement, namely visual

inspection and measurement of the dist-plate-inner

drum-bevel gear-campus components. brake-oil

pressure-hose, assembly, testing and adjusting, and

installing the steering brake components on the unit.

After checking and measuring the steering and brake

components, the results obtained include: (1) the

thickness of the dist 4.65mm (standard 4.7mm repair

limit 3.7mm) it can be said that the thickness of the

dist is still within the standard, but there are scratches

so it must be replaced ; (2) the thickness of the plate

is 2.85mm (standard 2.9mm repair limit 2.0mm) it can

be said that the thickness of the plate is still within the

standard, but there are molds that must be replaced;

(3) the RH inner drum is badly cracked and must be

replaced; (4) measurements on the bevel gear, tooth

contact are still within the standard limits and the

backlash is calculated at 6kgm (standard 2-6kgm) so

that the backlash is declared safe; (5) brake lining is

not up to standard so it must be replaced; (6) on the

oil pressure when checking, the results are 15kg/cm²

for the clutch and 16.5kg/cm² for the brake so that the

oil pressure is reached.

When checking finds components that are not

standard, they must be replaced, because if they are

not replaced, they will result in multifunction, namely

malfunctions or not working optimally on the system

and errors during operation of the unit. Things that

must be done in the future when going to do overhaul

steering and brakes, namely when doing work must

always refer to the SOP, mark components, document

activities, and check consistently before installing.

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ACKNOWLEDGEMENTS

There are many obstacles in completing this

research, and this work would not have been possible

without the support of several parties.

For that, I would like to thank all parties who have

been willing to work so far and other related writings.

Director of the Nunukan State Polytechnic who has

provided support to me in completing this research.

I also want to thank my family and friends who

have always supported me in completing this

research.

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Global chassis control system using suspension,

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