Undercarriage and structures, Front linkage, Strong, stable and easy to maneuver – Milton CAT 311D LRR User Manual
Page 6: Reliable, durable and versatile

Caterpillar uses advanced engineering and software to analyze 
all structures, creating a durable, reliable machine for the 
toughest applications. More than 70 percent of the structural 
welds are robotic and achieve additional penetration over manual 
welds. These structural components and undercarriage are the 
backbone of the machine’s durability.
Carbody Design
X-shaped, box section carbody provides excellent resistance 
to torsional bending. Robot-welded track roller frames are 
press-formed, pentagonal units that deliver exceptional strength 
and service life. Idler and center guards help maintain track 
alignment when traveling or working on slopes.
Grease Lubricated Track
Grease lubricated track protects the track link, delivers long track 
pin and bushing inner wear and reduces sound levels.
Travel Motors
Travel motors with automatic speed selection let the 311D LRR 
automatically change up and down from high and low speeds 
in a smooth controlled manner.
Undercarriage and Structures
Strong, stable and easy to maneuver
Front Linkage
Reliable, durable and versatile
Built for performance and long service life, Cat booms and 
sticks are welded, box-section structures with thick multi-
plate high strength steel fabrications. Service intervals are 
extended with self-lubricating bearings that resist corrosion 
and galling for superior durability.
Boom
The boom is designed for maximum digging capability and 
is robotic welded to ensure consistent quality. This allows 
excellent all-around versatility and a large working envelope.
Stick
Three stick options are available to meet your application 
needs and increase performance and productivity. A new 
2.6 m (8'6") intermediate stick is available to provide long 
reach and increased digging and lifting capability.
