303Ha

Question 1

An undercarriage system must provide a balance between adequate traction, machine
stability and satisfactory load carrying capacity

Answer 1

true

Question 2

The load carrying capacity of an undercarriage is determined mostly by the:

Answer 2

width of each track shoe.

Question 3

The stability of the machine is more important when the machine is an excavator
rather than a crawler tractor equipped with a dozer.

Answer 3

true

Question 4

A tracked crane is more suitable for:

Answer 4

lifting heavy loads that are very near to the machine.

Question 5

Identify six (6) major components that comprise a typical undercarriage system.

Answer 5

a) track frames
b) pivot shaft and equalizer bar
c) track chain
d) track and carrier rollers
e) drive sprocket
f) idlers
g) track tension and recoil mechanisms
h) protective devices (guards)

Question 6

Explain the main function of the track frame.

Answer 6

provides a solid support for the remaining undercarriage
components.
also absorbs shock loads caused by collisions between
the track assembly and immobile objects.

Question 7

The following type(s) of track links are available for use as required by a specific
track chain application:

Answer 7

any of the above links could be used in track chains.

Question 8

A master pin and a split master link have one function in common with each other.
Explain that function.

Answer 8

The master pin and the split master link are both used to hold the track chain
together. The master pin must be removed to split the track chain while the split link
must be disconnected in order to split the track chain.

Question 9

A machine is operating on soil that could cause soil packing in and around the track
chain. Identify the type of track shoe you would recommend for this type of operating
condition

Answer 9

When soil packing is a problem the machine should be equipped with open centre
track shoes.

Question 10

A low mount final drive and drive sprocket system could be used on:

Answer 10

any of the above machines are correct.

Question 11

Explain the major difference between pedestal (carrier) rollers and track rollers.

Answer 11

Carrier rollers are mounted on pedestal members on top of the track frame and
support the weight of the top track. Track rollers are mounted on the bottom of the
track frame and help support the weight of the machine.

Question 12

The three track and carrier roller configurations are?

Answer 12

Pedestal (carrier) rollers
Conventional track rollers
Bogie style track rollers

Question 13

Pedestal rollers are located where in the track assembly? And perform what task?

Answer 13

They are located on the top section of the track assembly and support the weight of the track above the frame

Question 14

Conventional (track) rollers function is to?

Answer 14

Transmit the weight of the machine to the track chain and transmit shock loads to the track frame. As well as maintain track chain position through the flanges

Question 15

Bogie style rollers are a pivoting roller assembly the purpose of this is?

Answer 15

To maximize the amount of track surface area in all load conditions

Question 16

Two types of roller shells are?

Answer 16

Double and single flange rollers

Question 17

In many tracked applications a unit has both single and double flange rollers used. What style roller goes before the sprocket?

Answer 17

Single flanged roller is always located next to the sprocket

Question 18

Track links are connected together using one of two main track link configurations. What are they?

Answer 18

Flush type and the interlocking type

Question 19

Where are flush type track links used?

Answer 19

At the point where the master pin is located.

Question 20

Disadvantage of flush type track links?

Answer 20

increased chance of contamination and therefore increased wear

Question 21

Common track pad designs? (5)

Answer 21

• standard grouser,
• open centre grouser,
• all purpose (multi-grouser or street pads),
• rubber and
• specialty shoes (extreme service).

Question 22

What type of track pad would be used when soil conditions cause packing between the drive sprocket teeth and the track chain?

Answer 22

Open centre track pads

Question 23

What is the seal that prevents lubricant loss in a carrier roller assembly?

Answer 23

A duo cone seal.

Question 24

What does the duo cone seal consist of?

Answer 24

2 torc rings (rubber seals) and 2 metal sealing rings.

Question 25

What is the function of the idler?

Answer 25

When they are connected to the track tensioner they absorb impact shocks during operation.

Question 26

What function does the centre flange have on the idler?

Answer 26

It helps maintain alignment of the track during operation.

Question 27

The idlers and rollers of a machine are similar but have one distinct difference, what is it?

Answer 27

The idlers are not fixed as the rollers are.

Question 28

Track tension specifications can be found where?

Answer 28

Service manual and operators manual. All manufacturers have individual specs.

Question 29

Tight tracks cause what?

Answer 29

Excessive wear on all under carriage components.

Question 30

Loose tracks have many ways of being adjusted, name them.

Answer 30

Threaded rod on smaller machines, pneumatic adjusters and hydraulic adjusters on larger machines.

Question 31

Major undercarriage subassemblies are identified as?

Answer 31

• Track frames
• Pivot shaft and equalizer bar
• track chain
• track and carrier rollers
• drive sprocket
• idlers
• track tension And recoil mechanism
• protective devices

Question 32

Track Frame provides mounting for what components?

Answer 32

Track rollers, carrier rollers, front and rear idlers, track tension and recoil mechanism

Question 33

Track frame assembly, when track chain and track pads are installed provide what for the machine?

Answer 33

Support during operation

Question 34

Explain a fixed track frame..

Answer 34

Track frames are unable to move independently

The machine, central frame and both track frames operate as a single unit

Increases machine stability

Question 35

Explain oscillating track frames..

Answer 35

Also known as swing frames for their ability to swing up and down

Uses and equalizer bar to support the front for the machine

Inner diagonal arm attached under machine to help the individual track frames stay in alignment with the machine frame