A loaded semitrailer is waiting for its tractor. Why check cargo securement before the tractor backs into the coupling?
Correct answer: Coupling can move the trailer and shift unsecured cargo
The coupling inspection includes making sure cargo is secured against movement caused by the tractor coupling to the trailer. A stationary trailer still needs that protection before the maneuver starts.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-8, physical 89 > 6.4.1 Coupling Tractor-Semitrailers > Step 2 Inspect Area and Chock Wheels ↗
A tractor is positioned diagonally to a parked semitrailer before backing underneath it. What is the concern with continuing that approach?
Correct answer: It could push the trailer sideways and damage its supports
The manual calls for positioning the tractor directly in front of the trailer. Backing underneath at an angle can force the trailer sideways and break its landing gear.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-8, physical 89 > 6.4.1 Coupling Tractor-Semitrailers > Step 3 Position Tractor ↗
Before going beneath the trailer to inspect the coupling, the driver has set the parking brakes and placed the transmission in neutral. What further preparation does the manual specify?
Correct answer: Shut off the engine and take the key
The manual includes engine shutdown and taking the key so another person cannot move the truck while the driver is underneath it. These actions are part of securing the vehicle, not a replacement for the parking brake and neutral.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-8, physical 89 > 6.4.1 Coupling Tractor-Semitrailers > Step 12 Secure Vehicle ↗
During a properly prepared coupling-security check, the landing gear is slightly off the ground and the trailer brakes remain locked. How does the driver check that the coupling holds?
Correct answer: Pull gently forward against the braked trailer
A gentle forward pull against the locked trailer brakes checks that the trailer is attached to the tractor. The subsequent secured visual inspection is also required; this item describes only the pull portion of the procedure.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-8, physical 89 > 6.4.1 Coupling Tractor-Semitrailers > Step 11 Check Connection for Security ↗
A secured visual inspection shows the fifth-wheel jaws gripping the kingpin's enlarged head instead of its shank. How should that finding be treated?
Correct answer: As an incorrect coupling that must be corrected
The jaws belong around the kingpin's shank, not the enlarged head. A closed-looking control does not make incorrect jaw engagement safe; the coupling must be right before the rig is moved.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-13, physical 94 > 6.5.1 Additional Things to Check during a Walk-around Inspection > Coupling System Areas; Figure 6.8 ↗
The fifth-wheel locking lever is in its lock position, but the separate safety latch is not engaged. What does the inspection still require?
Correct answer: Put the safety latch in its proper securing position
The manual requires checking both the locking lever and the safety latch. Some fifth-wheel designs require the catch to be placed by hand, so lever position alone is insufficient.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-8, physical 89 > 6.4.1 Coupling Tractor-Semitrailers > Step 13 Inspect Coupling ↗
The trailer lights work during a check, but the electrical connector's safety catch has not been fastened. What remains to be done?
Correct answer: Fasten the connector's safety catch
The coupling procedure requires plugging in the electrical cord and fastening its safety catch. Working lights at one moment do not establish that an unsecured plug will remain connected.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-9, physical 90 > 6.4.1 Coupling Tractor-Semitrailers > Step 14 Connect the Electrical Cord and Check Air-lines ↗
The landing gear is fully raised, but its crank handle is hanging loose. What should the driver do before departure?
Correct answer: Secure the crank handle in its proper position
Raising the landing gear is followed by securing the crank handle. The walk-around also checks that the handle is in place and secure.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-9, physical 90 > 6.4.1 Coupling Tractor-Semitrailers > Step 15 Raise Front Trailer Supports (Landing Gear) ↗
After coupling, the trailer's full weight rests on the tractor. Which clearance does the manual specifically tell the driver to check at this stage?
Correct answer: The gap between the tractor tires and the trailer nose
With the trailer's weight on the tractor, the driver checks that the tops of the tractor tires have enough clearance below the trailer nose. A check made before the weight transfers does not establish this loaded clearance.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-9, physical 90 > 6.4.1 Coupling Tractor-Semitrailers > Step 15 Raise Front Trailer Supports (Landing Gear) ↗
A sliding fifth wheel has been moved forward. Which turning clearance must be checked before accepting that position?
Correct answer: Cab, trailer, frame, and landing-gear clearances
A fifth wheel too far forward can put the tractor frame against the landing gear or the cab against the trailer during a turn. The slide's position must leave adequate clearance.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-13, physical 94 > 6.5.1 Additional Things to Check during a Walk-around Inspection > Coupling System Areas > Sliding fifth wheel ↗
A sliding fifth wheel appears stationary, but one of its locking pins is missing. What does the manual's inspection require?
Correct answer: All locking pins must be present and locked in place
A stationary appearance does not verify the slide's locking system. The walk-around calls for every locking pin to be present and locked, as well as checking for other damage.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-13, physical 94 > 6.5.1 Additional Things to Check during a Walk-around Inspection > Coupling System Areas > Sliding fifth wheel ↗
A driver plans to leave a loaded semitrailer on ground that looks level but may be soft. What must be established about that parking surface?
Correct answer: That the surface can support the trailer's weight
Level appearance alone does not show that a parking surface will carry the trailer after the tractor is removed. The uncoupling procedure begins by checking the surface's ability to support that weight.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-9, physical 90 > 6.4.2 Uncoupling Tractor-Semitrailers > Step 1 Position Rig ↗
During uncoupling, the fifth wheel has cleared the trailer, but the driver pauses with the tractor frame still underneath. What is the reason for that intermediate position?
Correct answer: It helps support the trailer if the landing gear fails
The procedure retains the tractor frame beneath the trailer briefly as protection against failed or sinking landing gear. The driver then secures the tractor and verifies the trailer supports before pulling completely clear.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-9, physical 90 > 6.4.2 Uncoupling Tractor-Semitrailers > Step 7 Pull Tractor Partially Clear of Trailer ↗
After disconnecting a semitrailer, why does the manual say to hang the supported electrical cable with its plug pointing down?
Correct answer: To help prevent moisture from entering the plug
Pointing the disconnected plug downward helps keep moisture out. The cable must also be supported so it will not be damaged while the tractor moves.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-9, physical 90 > 6.4.2 Uncoupling Tractor-Semitrailers > Step 5 Disconnect Air-lines and Electrical Cable ↗
A pintle hook's latch closes, but its mounting is loose. Which assessment is correct?
Correct answer: The mounting can fail despite a closed latch
A pintle hook must be securely attached to its mounting surface as well as properly latched. A sound latch cannot compensate for a mounting that may separate from the tow vehicle.
Source: New Jersey CDL Manual, March 2025 cover; Section 6, July 2017 footer, printed 6-10, physical 91 > 6.4.3 Coupling a Pintle Hook > Step 1 Inspect Pintle Hook ↗
