Loader & Backhoe
1.5 hours
Learning Objectives
- •Identify the major components of a loader-backhoe (TLB) and a wheel loader
- •Explain the function of stabilizers on a loader-backhoe during backhoe operations
- •Describe the geometry and controls of the backhoe boom, dipperstick, and bucket
- •Compare wheel loader and loader-backhoe load-handling capabilities
Topics Covered
- •Loader-backhoe (TLB) layout: loader end, articulation point, backhoe end
- •Loader bucket: cutting edge, bolt-on teeth (optional), spill guard, attachment frame
- •Loader lift arms: parallel linkage for level bucket during raise/lower
- •Backhoe boom and dipperstick: digging geometry and maximum reach/depth
- •Backhoe bucket: trapezoidal vs. ditching vs. general purpose buckets
- •Stabilizers (outriggers): must be deployed before backhoe operation; prevent tip-over
- •Stabilizer pads: protect pavement and distribute load
- •TLB operator seat swing: rotates from loader-facing to backhoe-facing position
- •Wheel loader: articulated frame steering, large bucket capacity, high dump height
- •Wheel loader tire types: lug (off-road) vs. smooth (stockpile) vs. rock (quarry)
- •Quick-attach systems: allow bucket and fork swap without tools
- •Load-handling: loader-backhoe lifts from backhoe boom only; wheel loader from bucket
Resources
Self-Check Questions
Question 1: Before beginning backhoe operations with a loader-backhoe, what must the operator do with the stabilizers?
- A. Leave them retracted — they are only used on slopes
- B. Deploy them to the ground so all four contact points bear weight(correct)
- C. Deploy only the two rear stabilizers directly behind the backhoe boom
- D. Partially lower them to reduce ground disturbance
Show Explanation
Explanation:
Both stabilizers must be fully deployed to firm ground before any backhoe digging begins. Without stabilizers deployed, the rear of the machine can lift or tip sideways when the bucket curls under load.
Question 2: On a loader-backhoe, the operator's seat has a swing feature. What is its purpose?
- A. It allows the operator to lean away from the backhoe during digging
- B. It rotates 180° so the operator faces the backhoe end when switching from loader to backhoe controls(correct)
- C. It tilts the operator's position to improve visibility over the loader bucket
- D. It locks the operator in position during travel on rough terrain
Show Explanation
Explanation:
The swing seat rotates approximately 180° so the operator faces the backhoe attachment and its dedicated control levers, rather than the loader controls. Always come to a complete stop before swinging the seat.
Question 3: Which component allows a wheel loader to turn in a tight radius despite its large size?
- A. Rear-wheel steering similar to a forklift
- B. Articulated frame steering — the front and rear halves pivot at a central joint(correct)
- C. Independent track steering
- D. All-wheel crab steering
Show Explanation
Explanation:
Wheel loaders use articulated frame steering: the front and rear halves of the machine pivot relative to each other at a central joint, allowing a very tight turning radius. This articulation point is a pinch-point hazard — never stand between the halves while the engine is running.
Question 4: A loader-backhoe operator wants to pick up a concrete pipe using the backhoe. What must they verify before making the lift?
- A. The loader bucket is raised to counterbalance the load
- B. The load is within the backhoe's rated lift capacity at the specific radius and angle(correct)
- C. The stabilizers are retracted to allow the machine to reposition
- D. The TLB has at least half a tank of fuel
Show Explanation
Explanation:
The backhoe end of a TLB has a rated lift capacity that varies with radius and boom/dipperstick angle. Exceeding this capacity can tip the machine over the rear. Stabilizers must be deployed for any lift, and the load chart or manufacturer rating must be respected.
Question 5: What hazard does the articulation joint of a wheel loader create for ground personnel?
- A. Electrical shock from hydraulic lines
- B. Crush hazard — the front and rear halves can pinch together during steering(correct)
- C. Slipping hazard from hydraulic fluid leaks at the joint
- D. No hazard; the joint is fully guarded by design
Show Explanation
Explanation:
The articulation joint is a severe crush/pinch-point hazard. Personnel must never stand between the front and rear halves of the machine while the engine is running. Always chock the frame before performing any maintenance in this area.