190303hA Flashcards
Three functions of the undercarriage system?
Traction
Load Carrying
Machine Stability
(flotation)
What is minimized when a narrow track pad is used?
The amount of undercarriage component wear
ROPS stands for?
Roll Over Protective Structure
LGP stands for?
Low Ground Pressure
When do fixed track frames move independently?
never
What is another name for oscillating track frames?
Swing Frames
What are the three major components of a track chain?
Track Links
Track Pins
Bushings/Seals
Describe the average track link design?
Solid, One-Piece
What is the design of a master link?
Split
What are two types of track pins?
Standard and Master
Lubricated track is sometimes called?
a sealed and lubricated track SALT
What do larger track pads provide?
Better flotation
The shortest pad helps reduce wear because?
Shortens lever length
24” pads should be used in what conditions?
Loose, wet, starting construction
30-32” are used for what conditions?
Wet, Muddy ground. LPG & flotation is better
What are two styles of rollers?
Single or double flanged
What does an idler do on an undercarriage?
Change direction of tracks
Why do bulldozers use a non-fixed undercarriage?
To maintain ground contact
What are two major causes of undercarriage failure?
Too wide of pads and wrong track tension
Some tracks are attached to the drive chain, why do they have unique wear patterns?
Since they are attached the chain they will wear on the roller in different ways depends on ground level and condition
Side hill work will cause wear on what?
Uphill side of the chain and down hill side of the flange (roller), on both tracks
Other names for track frames?
Swing frame & Roller frame
Equalizer bars are set underneath?
The engine
Pin style equalizer bars do what?
Hold tracks in alignment
How are pins installed in the link?
Pressed in
What turns in a chain?
Pin turns in a bushing. Pin &pushing do not turn in their bore in the link
Which direction causes more wear on the bushings?
In Reverse
What are the two different split master link styles?
Fine or coarse tooth joint
Why do we not heat up pins to remove pin and bushings from chain links?
You will affect the heat treating and cause pre mature failures
What happens if you lubricate the track pins and bushings?
you can attract dirt, which can cause pre mature wear
Lubricated track pins are a serviceable part of a track chain?
NO, if the seals are leaking they must be removed and replaced
What can one higher temp pin on a chain tell you?
Hint: on SALT tracks
That higher temp pin has leaked all its lubrication out and needs to be repaired
What is a better way to describe a chain stretching
Track pitch is being worn out
Describe track pitch
Distance from pin to pin to pin (on the links)
Does wearing the link out make the chain longer?
No
What is the most simply type of chain link?
Flat or Flush Link
What are two styles of master link coupling?
Split link and Pin (in a flush link system)
How is contamination restricted in a flush link system?
By small clearances between the left and right tack link assemblies
What should you use when driving master pins in?
Drift punch
What type of profile does an interlocking type of link have?
Stepped Profile
What is the most common style of link design?
Interlocking type
Why use an open centre grouser track pad?
Prevent packing
What happens to track tension when material is packed under the track pads?
Track tension increases, causing pre mature wear
Where do you see the most wear when track tension is too tight?
Sprockets and pin/bushings
How many grousers are on “street pads”?
atleast 2
What are two styles of rubber pads?
bolt on or one piece
How is rubber tracks driven?
Rubber idler, static friction, tension
What is the best lubricant when cutting rubber?
Water
If track is slipping what is the first check?
Track pressure, tension or slack
Bogie track rollers do what?
help maintain ground contact
What are bogie track rollers working with to maintain ground contact?
Equalizer bars
What is the most common final drive?
Planetary style
What does final drive give us for gear ratio?
Reduction
Low final drive is on what plain?
Track frame
What are some pros to high drive systems?
High Operator seat = better visibility
Final drive is up and out of the dirt/mud
Reduces shock loads
How are one piece sprockets attached?
Welded
What does bolt on sprockets eliminate or reduce?
The chance of misalignment the sprocket during install
When welding on a sprocket where should the ground be attached?
TO THE SPROCKET, to protect the final drive bearings
What is the big advantage of removing and installing segmented sprocket?
The segments can be replaced while the track/chain are still assembled on the machine
Rollers have what two flange design?
Double or single
Are flanges located on the inside or outside of roller?
Outside
Are flanges located on the inside or outside of roller?
Inside and outside. but they must have ONE on the outside
What will happen if the tracks are not aligned?
Idler will have uneven wear
When there is an alignment problem, on a piece of equipment that has oscillating side frames, what should you look at?
Equalizer pin wear
What is on the inside of a roller?
Bearing or bushing and some type of seal
What are the four types of tracks links?
Split master
flush mount
one-piece links
interlocking links
True or false: Top Carrier roller flanges are on the inside and bottom rollers have flanges on the outside.
True. Bottom rollers can also have flanges on the inside
Where do we correct track alignment on a fixed track?
At the idler
Why should spring recoil systems be worked around carefully?
Heavy recoil springs are always preloaded by retainer, stored energy
What can cause a track to be loose?
broken spring - rough ride, keeps tension when refilled leaking adjuster (leaking grease) - repetitive refill
What can cause a track to be excessively tight?
mud packing - clean
Sheared center pin or broken retaining nut on a recoil system
What can a spring recoil system work with as a unit?
Hydraulic track tensioner
What can be done to cage the spring recoil system while it is on the machine?
You can use the blade or bucket against the idler to cage the recoil system
What can cause a rough ride in one track and not the other?
A broken spring in the recoil mechanism
In a air/nitrogen recoil system, the track tension is being loss daily what could be the cause?
The nitrogen is being leaked
In a air/nitrogen recoil system, the track tension is becoming tight during the operation. What could be the cause? Undercarriage is clean
Grease is being leaked out
In a air/nitrogen recoil system, the track tension is becoming tight during the operation. What could be the cause? Undercarriage is clean
Grease is being leaked out
To increase track tension in a spring recoil system what must be done?
Grease must be added
To decrease track tension on a spring recoil system what must be done?
Use the bleed screw to allow some grease to come out
DO NOT PUT YOUR FACE NEAR THE BLEED SCREW
