Machine Frames

Question 1

Frames are constructed from welded-together _______________
and ____________ sections.

Answer 1

plate steel
cast steel

Question 2

Frames will likely fail at ____________ if the frame is
pushed past design limits

Answer 2

one of the welds

Question 3

______________ machines have two-piece frames

Answer 3

Articulated

Question 4

Excavators have an upper and lower frame held together
with a __________________.

Answer 4

rotex bearing

Question 5

Frame inspection should be part of regular maintenance,
and focus should be concentrated on _________________

Answer 5

welds and threaded
holes.

Question 6

Frames can be ________ and ________ to prevent recurring failures.

Answer 6

repaired and reinforced

Question 7

Frames should always be covered with _______ to
prevent rust.

Answer 7

paint

Question 8

Any welding repairs should not create stress risers by
________________________

Answer 8

angling and curving reinforcements.

Question 9

Suspension systems allow movement between a machines
frame and _______________

Answer 9

its drivetrain.

Question 10

_______________ gives the operator a smoother ride and keeps the tires or tracks engaged with the ground
longer.

Answer 10

Suspension systems

Question 11

Some older and/or small machines will use springs for
suspension. Springs can be ________, ____________ or __________

Answer 11

leaf type, coil type, or rubber.

Question 12

_______ springs are stacked up in shortening multiples and
held stationary at one end. The other end pivots in a
shackle, and an axle is held to the spring assemblies’ center
with U-bolts.

Answer 12

Leaf-type

Question 13

______ springs can be for axle suspension but the axle needs
to have links to keep it in place.

Answer 13

Coil

Question 14

________________ use a hydraulic piston, oil, and an orifice to
reduce spring oscillations.

Answer 14

Shock absorbers

Question 15

A sprung axle usually has a set of two shock absorbers
mounted to it. The other end will be _______________

Answer 15

mounted to the frame.

Question 16

Front axles on backhoe loaders and rear axles on wheel
loaders oscillate. This is a simple type of suspension that
allows the axle to pivot a few degrees on a _________ or __________

Answer 16

center pin or bolt
on trunnions.

Question 17

Suspension cylinders act like _________ and shock absorbers
and are mostly found on trucks to give ________________ and
allow the machine to travel fast over rough ground.

Answer 17

springs
a smooth ride

Question 18

Most suspension cylinders use ___________ for the spring
effect and _____________ for the damping action.

Answer 18

nitrogen gas
hydraulic oil

Question 19

__________ must
be precharged to a certain pressure or to make the rod
extend a certain length.

Answer 19

suspension cylinders

Question 20

How do you change ride height or level the machine?

Answer 20

Oil can be fed into or drained out of active suspension cylinders

Question 21

Ride control is a form of suspension for backhoe loaders
and wheel loaders that introduces _______________ to the
head end of the boom circuit.

Answer 21

an accumulator

Question 22

Scrapers have ______________that allow some movement
between the tractor section and the scraper section of the
machine.

Answer 22

cushion hitches

Question 23

A load cylinder and linkage allows movement
between the frame sections, and an accumulator provides
______________.

Answer 23

spring action

Question 24

Walking beam suspension can be found on the __________________

Answer 24

rear tandem
axles of articulated rock trucks

Question 25

Walking beam suspension allows a few degrees of
oscillation between ____________

Answer 25

all four wheels.

Question 26

In a walking beam suspension, travel is cushioned with
_____________, and axles are located _____________.

Answer 26

rubber blocks
with torque rods

Question 27

Payload scale systems can use suspension components to
translate pressures into ________________

Answer 27

payload weights

Question 28

______________ allow track frames
to pivot a few degrees, and track rollers may have a bogie
system to allow them to follow the underfoot profile.

Answer 28

Equalizer bars

Question 29

What are some operator complaints related to machine frames and
suspension systems?

Answer 29

rough ride
noises
excessive oscillation
machine not level.

Question 30

Diagnostic procedures start with knowing the system and a
_______________

Answer 30

thorough visual inspection.

Question 31

Most suspension components that allow movement require
_______________

Answer 31

regular greasing.

Question 32

How can adjustments be made to accumulator or strut
precharge pressures?

Answer 32

This requires a charging kit that
includes special tools.