Fifth Wheels and Trailer Couplings

Holland Fifth Wheels

General Information

The 2535 sliding fifth wheel models incorporate a Model 3500 fifth wheel ( Fig. 10.1 ), equipped with either an air-operated release slide, or a manual release slide. Sliding fifth wheel assemblies are mounted on a baseplate that permits forward and rear movement along notched rails. Plungers are meshed into teeth on the baseplate to lock the sliding mechanism. Disengagement of the sliding member is accomplished when the plungers are withdrawn (manually or air-operated), releasing the fifth wheel assembly so that it can be positioned for optimum weight distribution over the tractor axles.

1. Kingpin Lock Mechanism
2. Kingpin Control Handle
3. Mounting Bracket

Fig. 10.1, Holland Fifth Wheel

The air-operated release slide assembly ( Fig. 10.2 ) contains a double-ended air cylinder which locks and unlocks both sides of the sliding member at the same time. The air cylinder is activated by a two-position air-control valve in the tractor cab.

NOTE: Baseplate rails not shown.

1. Kingpin Lock Control Handle
2. Double-Ended Air Cylinder
3. Slide Plunger Release

Fig. 10.2, Air-Operated Release Slide Assembly

The manual release slide assembly ( Fig. 10.3 ) is equipped with a single release lever. Pulling on the release lever unlocks both plungers.

NOTE: Baseplate rails not shown.

1. Kingpin Lock Control Handle
2. Plunger Release Handle
3. Plunger Release Spring
4. Plunger

Fig. 10.3, Manual Release Slide

A. Closed Position, Locked
B. Open Position, Unlocked

1. Release Handle and Spring
2. Adjustment Nut
3. Lock Halves
4. Lock Pivot
5. Sliding Yoke

Fig. 10.4, Type "B" Kingpin Lock Mechanism (bottom view)

Type "B" Kingpin Lock Mechanism

The Type "B" kingpin lock mechanism ( Fig. 10.4 ) utilizes two spring-loaded lock halves. The final forward motion of the kingpin into the open lock halves forces the locks to close in a 360-degree grip around the shoulder and neck of the kingpin, positioning sliding yokes between the lock halves and tapered rib members of the fifth wheel understructure. The kingpin can be released only by manually operating the kingpin lock control handle. The adjustment nut will compensate for wear on the lock or kingpin.

Lockguard

The Holland lockguard ( Fig. 10.5 ) is a device that prevents a false lockup, and is used on all models. The Lockguard is a spring-tensioned, smooth-surfaced tongue that the kingpin passes over and depresses when entering the lock mechanism. The Lockguard will prevent the locks from engaging before the kingpin fully enters the locks. If the kingpin enters the fifth wheel incorrectly and does not depress the tongue, the locks are unable to close.

Fifth Wheel Locking Operation

Locking the Fifth Wheel Mechanism

Before attempting to lock or unlock the fifth wheel lock mechanism of a sliding type fifth wheel, the slide release plungers must be in the locked position. This prevents the sliding member from moving rapidly to the far forward or rearward position, which could damage the fifth wheel or kingpin.

Chock the front and rear of the trailer tires to prevent the trailer from moving.

A standard fifth wheel plate must be kept lubricated to prevent binding between the tractor and trailer. A binding fifth wheel could cause erratic steering and loss of vehicle control, possibly resulting in personal injury or death.

The kingpin lock mechanism must be fully open, and the fifth wheel plate must be completely lubricated with chassis grease. For lubrication instructions, see Group 31 of the Columbia® Maintenance Manual .

Position the tractor so that the fifth wheel lock opening is in line (both vertically and horizontally) with the trailer kingpin. The kingpin should be in a position to enter the throat of the locking mechanism, to prevent a false lockup. See Fig. 10.5 . Adjust the trailer landing gear to give enough alignment height so that the fifth wheel picks up the trailer on the fifth wheel ramps.

A. Locks open.
B. Locks closed.
C. Kingpin correctly entering the lock. Note how the depressed tongue allows lock halves to close completely around the neck and shoulder of the kingpin.
D. Kingpin incorrectly entering the lock. Note how the steel tongue prevents lock halves from closing, preventing false lockup.

1. Fifth Wheel Plate
2. Trailer
3. Kingpin
4. Lockguard

Fig. 10.5, Lockguard Mechanism (rear view)

With the fifth wheel lock opening aligned with the trailer kingpin, back the tractor slowly toward the trailer, making sure that the kingpin correctly enters the throat of the locking mechanism. When the trailer is picked up by the fifth wheel, stop the tractor, then continue slow backward motion until positive lockup occurs.

Apply the tractor parking brakes.

Adjust the locks correctly to a maximum clearance of 1/8 inch (3 mm). Incorrect adjustment of the lock could cause the trailer to disconnect, possibly resulting in serious personal injury or death.

Make a visual check for proper kingpin lockup. Release the tractor parking brakes. Test for kingpin lockup by pulling on the trailer against the chocks. Check for correct maximum clearance between the lock halves. If more than 1/8-inch (3.2-mm) clearance exists between the lock halves, the lock must be adjusted. See Group 31 of the Columbia® Workshop Manual for adjustment procedures.

NOTICE

Always make sure the connect-hanger/support keeps the trailer air hoses and electrical cables positioned so that they do not rub on anything. Rubbing may wear through hoses or cables, resulting in air leaks, or exposed or broken wires, potentially affecting trailer brake or electrical systems.

After lockup is completed, connect the tractor-to-trailer air system lines and electrical cable to the trailer. Take care to prevent dirt or foreign material from entering the air lines.

Charge the air brake system with air. Make sure that the air connections do not leak.

Retract the trailer landing gear and secure the ratchet handle.

10.

Remove the chocks from the trailer tires.

11.

The load distribution on the front steering axle and rear drive axle(s) will have a direct effect on the steering control of the vehicle.

11.

Determine the front and rear axle weights by weighing the vehicle on scales designed for this purpose.

11.

The maximum axle weight ratings are shown on the Federal Motor Vehicle Safety Standard (FMVSS) label or Canadian Motor Vehicle Safety Standard (CMVSS) label attached to the left rear door post of the tractor. The desired load on the axle is no less than 80 percent of the maximum axle weight rating, but in no instances should the axle load exceed the maximum axle weight rating given on the FMVSS or CMVSS label.

Do not overload any tractor axle by improperly loading the trailer. This could cause erratic steering and loss of vehicle control, possibly resulting in serious personal injury or death.

Unlocking the Fifth Wheel Lock Mechanism

Apply the tractor parking brakes.

Pull the trailer air supply valve to cut off the air supply to the trailer.

Chock the front and rear of the trailer tires to prevent the trailer from moving.

Do not use the trailer air supply for parking trailers not equipped with spring parking brakes. This applies the trailer service brakes only. As air bleeds from the trailer brake system, brake application is lost. This could allow the unattended vehicle to roll away, possibly resulting in serious personal injury or death.

Lower the trailer landing gear until the weight is removed from the fifth wheel.

Disconnect the tractor-to-trailer air system lines and electrical cable. Plug the air lines to prevent dirt or foreign material from entering the lines.

Release the kingpin locking mechanism by pulling the kingpin lock control handle ( Fig. 10.1 ) to the outward position.

Slowly drive the tractor away from the trailer.

Fifth Wheel Slide Operation

Connect the trailer kingpin to the tractor fifth wheel. For instructions, refer to Holland "Fifth Wheel Locking Operation" in this chapter.

After positive lockup of the fifth wheel lock mechanism has been accomplished, release the sliding member using one of the following methods:

2.1

For air-operated models, set the cab-operated control switch ( Fig. 10.6 ) to UNLOCK.

Fig. 10.6, Cab Control, Fifth Wheel Slide

2.2

For manual release models, pull the release lever ( Fig. 10.3 ) using a release hook, or other suitable tool. Make sure both slide plungers have released. See Fig. 10.7 . If the plungers haven't released (haven't come out), lower the trailer landing gear to relieve pressure on the plungers.

A. Locked (engaged)
B. Unlocked (released)

1. Plunger

Fig. 10.7, Plunger Positions

Lower the trailer landing gear just enough to remove the weight from the tractor.

Pull the trailer air supply valve to cut off the air supply to the trailer.

Chock the front and rear of the trailer tires to prevent the trailer from moving.

After moving the fifth wheel to the desired position, be sure the trailer landing gear will not, at any time, come in contact with the tractor frame or other components. Make sure that the front of the trailer will not come in contact with the rear of the cab or with other components if they extend beyond the rear of the cab.

Slowly move the tractor forward or backward until the fifth wheel is in the desired location.

Apply the tractor parking brakes.

NOTE: The fifth wheel may have to be moved slightly to enable the locking plungers to enter the fully locked position.

Lock the sliding member into position using one of the following methods:

Check to be sure that the slide plungers are in the locked position. Failure to achieve complete lockup may allow disengagement of the tractor from the trailer, possibly resulting in serious personal injury or death.

8.1

For air-operated models, set the cab-operated control switch to LOCK. Visually check the slide plungers to make sure they are engaged in the fully locked position. See Fig. 10.7 .

8.2

For manual release models, trip the release lever ( Fig. 10.3 ) using a release hook or other suitable tool. Make sure that both plungers have locked (retracted into their pockets), and are fully engaged in the rack teeth. See Fig. 10.7 . It may be necessary to move the tractor slightly while keeping the trailer brakes locked.

The amount of load distribution on the front steering axle and rear drive axle(s) will have a direct effect on the steering control of the vehicle.

Determine the front and rear axle weights by weighing the vehicle on scales designed for this purpose.

Do not overload any tractor axle by improperly loading the trailer. This could cause erratic steering and loss of vehicle control, possibly resulting in serious personal injury or death.

Fifth Wheel Lubrication

For lubrication instructions, see Group 31 of the Columbia®Maintenance Manual .

ASF Simplex Series Fifth Wheels

General Information

The ASF Simplex series fifth wheels are used for pulling trailers having the standard 2-inch (51-mm) diameter kingpin. When installed as a stationary fifth wheel ( Fig. 10.8 ), they are bracket-mounted to the tractor frame in a position that best distributes the trailer load over the tractor axles. When used as a sliding fifth wheel ( Fig. 10.9 ), they are mounted on the Taperloc® sliding mount (air-operated or manual release).

1. Lubricant Grooves
2. Safety Latch
3. Operating Rod
4. Mounting Bracket

Fig. 10.8, Simplex Stationary Fifth Wheel

1. Baseplate
2. Bolted Stop
3. Baseplate Rail
4. Fifth Wheel Mount
5. Slider Saddle Plate
6. Safety Latch
7. Operating Rod
8. Operating Lever

Fig. 10.9, Taperloc Slide, Manually Operated Release

The fifth wheel lock mechanism for the trailer kingpin consists of a rotating jaw that grips the trailer kingpin and a spring-actuated lock. The jaw rotates on a jaw pin during coupling and uncoupling operations. Kingpin lockup occurs when the kingpin is forced into the jaw and the operating rod handle moves to the locked position. The kingpin is released either by activating a manual operating rod, or if equipped with Touchloc®, by a dash-mounted release knob that activates an air cylinder underneath the top plate. The air cylinder activates the operating rod. The operating rod is located on the left side of the fifth wheel for Simplex II fifth wheels, and on the right side for the Simplex fifth wheel assembly.

On sliding fifth wheels, the top plate is mounted on a sliding saddle plate that slides along the baseplate attached to the tractor frame. The baseplate rails allow forward and rear movement of the slide assembly, for optimum weight distribution over the tractor axles.

Tapered slots in the baseplate rails, aligned in 4-inch (102-mm) increments, provide for location of the fifth wheel along the baseplate. Retractable, spring-actuated lockpins are positioned through the slots to hold the fifth wheel in the desired position. The lockpins are retracted either manually or by an air-operated cylinder controlled from the cab.

The manually operated slide contains an operating rod ( Fig. 10.9 ) that unlocks both sides of the plate at the same time.

The air-operated sliding saddle plate contains an air cylinder that moves the operating lever to unlock both sides of the plate at the same time. The air cylinder is activated by a two-position air-control valve in the tractor cab.

Fifth Wheel Lock Mechanism for Trailer Kingpin

The Simplex Series fifth wheel lock mechanism ( Fig. 10.10 ) consists of a rotating jaw and a spring-actuated lock that grips the trailer kingpin. The jaw rotates on an eccentric pin during coupling and uncoupling operations. The spring-actuated lock holds the jaw in the locked position once kingpin lockup has occurred.

A. Locked Position
B. Jaw movement compresses spring
C. Fully open

1. Operating Lever
2. Safety Latch
3. Jaw
4. Jaw Eccentric Pin
5. Lock
6. Spring

Fig. 10.10, ASF Simplex Series Kingpin Locking Mechanism Operation

In the locked position, there is approximately 1/16-inch (1.6-mm) clearance between the jaw and kingpin. The jaw eccentric pin can be removed and rotated to compensate for wear and maintain an approximate 1/16-inch (1.6-mm) clearance during service.

Placing the operating rod in the lockset position moves the lock away from the jaw. This action unlocks the jaw so that it can be rotated by movement of the kingpin. When the tractor is moved out from under the trailer, the kingpin will rotate the jaw until the jaw is in the unlocked position, allowing the kingpin to move out of the mechanism. With the jaw in the fully open position, the operating rod drops out of the lockset position, and the fifth wheel is ready for coupling. See Fig. 10.11 .

1. Safety Latch
2. Operating Rod (locked)
3. Operating Rod (unlocked)

Fig. 10.11, Simplex Kingpin Locking Mechanism, Locking and Unlocking

During coupling, the kingpin contacts and rotates the jaw into the locked position. This action automatically moves the operating rod into the locked position. This securely locks the jaw around the kingpin. In the locked position the safety latch swings freely over the operating rod. See Fig. 10.12 .

1. Safety Latch
2. Operating Rod

Fig. 10.12, Simplex Kingpin Locking Mechanism, Safety Latch (locked position)

Fifth Wheel Locking and Unlocking

Locking the Fifth Wheel Lock Mechanism

Chock the front and rear of the trailer tires to prevent the trailer from moving.

Before attempting to lock the fifth wheel lock mechanism of a sliding type fifth wheel, the slide locking handle must be in the locked position. This prevents the sliding member from moving rapidly to the far forward or rearward position, which could damage the fifth wheel member or kingpin.

The fifth wheel jaw must be fully open. Make sure that the operating rod is in the unlocked position. The fifth wheel must be completely lubricated with chassis or multi-purpose grease. For lubrication instructions, see Group 31 of the Columbia® Maintenance Manual .

Make sure the fifth wheel top plate is tilted so the ramps are as low as possible. If equipped with an air suspension, make sure the air bags are completely inflated.

Position the tractor so that the center of the fifth wheel is in line with the trailer kingpin. The kingpin should be in a position to enter the throat of the locking mechanism. See Fig. 10.10 . Adjust the trailer landing gear so that the lower front trailer edge contacts the top surface of the tilted fifth wheel plate, approximately 8 inches (20 cm) before the fifth wheel center.

With the fifth wheel lock opening aligned with the trailer kingpin, back the tractor slowly toward the trailer, making sure that the kingpin enters the throat of the locking mechanism. Continue backward motion until positive lockup occurs.

Apply the tractor parking brakes.

Make a visual check (even if equipped with the Touchloc air-operated system) for positive kingpin lockup. The trailer bed plate must be flush on the fifth wheel plate surface. When positive lockup has occurred, the fifth wheel operating rod will have moved inward to the locked position, and the safety latch will swing freely over the operating rod. See Fig. 10.12 .

NOTE: Only when the operating rod is fully retracted in the locked position will the safety latch be freely rotated down.

Release the tractor parking brakes. Test for kingpin lockup by pulling on the trailer against the chocks.

NOTICE

After lockup is completed, connect the tractor-to-trailer air system lines and electrical cable to the trailer. Take care to prevent dirt or foreign material from entering the air system lines.

10.

Charge the air brake system with air. Make sure that the air connections do not leak.

Adjust the jaw pin if there is more than 1/8-inch (3-mm) clearance between the kingpin and the lock. Incorrect adjustment could cause the trailer to disconnect, possibly resulting in serious personal injury or death.

11.

With the trailer wheels chocked and the brakes set, check for clearance between the kingpin and the fifth wheel jaws by moving the tractor forward and backward against the locked kingpin. A clearance of approximately 1/16 inch (1.6 mm) between the jaw and kingpin is allowable. When clearance between the jaw and kingpin exceeds 1/8 inch (3 mm), adjust the jaw to restore the 1/16-inch (1.6-mm) clearance between the jaw and kingpin. For instructions, see Group 31 of the Columbia® Workshop Manual .

12.

Retract the trailer landing gear, and secure the ratchet handle.

13.

Remove the chocks from the trailer tires.

14.

The load distribution on the front steering axle and rear drive axle(s) will have a direct effect on the steering control of the vehicle.

14.

Determine the front and rear axle weights by weighing the vehicle on scales designed for this purpose.

14.

Do not overload any tractor axle by improperly loading the trailer. This could cause erratic steering and loss of vehicle control, possibly resulting in serious personal injury or death.

Unlocking the Fifth Wheel Lock Mechanism

Apply the tractor parking brakes.

Pull the trailer air supply valve to cut off the air supply to the trailer.

Chock the front and rear of the trailer tires to prevent the trailer from moving.

Lower the trailer landing gear until the trailer rises about 1/2 inch (13 mm).

Disconnect the tractor-to-trailer air system lines and electrical cable. Plug the air lines to prevent dirt or foreign material from entering the lines.

Before attempting to unlock the fifth wheel lock mechanism of a sliding type fifth wheel, the slide operating rod must be in the locked position, and the slide lockpins must be in the locked position (fully inserted in baseplate rail slots). This prevents the sliding member from moving rapidly to the far forward or rearward position, which could damage the fifth wheel member or kingpin.

If equipped with a manual kingpin lock release: Release the kingpin lock mechanism by raising the safety latch to the rear and pulling the lock operating rod out and up into the lockset position. See Fig. 10.11 . The offset of the lock control upper rod should bottom against the plate casting above the hole. If the operating rod cannot be pulled to the lockset position, back the tractor slightly to release the kingpin force against the jaw.

If equipped with an air-operated kingpin lock release: Pull the air-release knob on the dash. From outside the cab, visually check that the operating rod has bottomed out against the plate casting above the hole. See Fig. 10.11 . If the operating rod isn't in the unlocked position, back the tractor slightly to release the kingpin force against the jaw.

IMPORTANT: If equipped with an air-operated lock release, you still must make a visual check of the operating rod to make sure it is in the unlocked position

Slowly drive the tractor away from the trailer.

Fifth Wheel Slide Operation

Chock the front and rear of the trailer tires to prevent the trailer from moving.

Connect the trailer kingpin to the tractor fifth wheel. For instructions, refer to "Fifth Wheel Locking Operation," in this chapter.

After positive lockup of the fifth wheel lock mechanism has been accomplished, release the slide using one of the following methods:

3.1

For air-operated models, set the cab-operated control switch ( Fig. 10.13 ) to UNLOCK.

Fig. 10.13, Cab Control, Fifth Wheel Slide

3.2

For manually operated models, raise the safety latch and pull the slide operating rod ( Fig. 10.9 ) outward until the shoulder is outside of the operating rod support, then lower the operating rod as far as it will go.

Lower the trailer landing gear just enough to remove the weight from the tractor.

Pull the trailer air supply valve to cut off the air supply to the trailer.

Slowly move the tractor forward or backward until the fifth wheel is in the desired location.

Apply the tractor parking brakes.

Check to be sure that the lockpins are seated in the holes and that the operating rod is in the locked position with the safety latch securing the operating rod. Failure to achieve complete lockup may cause the trailer to detach from the tractor, possibly resulting in serious personal injury or death.

NOTE: The fifth wheel may have to be moved slightly to enable the locking pins to enter the fully locked position.

Lock the sliding member into position using one of the following methods:

For air-operated models: Set the cab-operated control switch to LOCK. Visually inspect the lockpins to make sure they have seated in the baseplate rail holes.

For manually operated models: Raise the operating rod so that it is free to move inward. Make sure that the lockpins have seated in the baseplate rail holes and the operating rod moves into the locked position. Also, the safety latch must drop downward so that it holds the operating rod in the locked position.

The amount of load distribution on the front steering axle and rear drive axle(s) will have a direct effect on the steering control of the vehicle.

Determine the front and rear axle weights by weighing the vehicle on scales designed for this purpose.

Adjust the fifth wheel slide correctly, and do not overload any tractor axle by incorrectly loading the trailer. Incorrect slide adjustment or improper axle loading could cause erratic steering and loss of vehicle control, possibly resulting in serious personal injury or death.

Fifth Wheel Lubrication

The fifth wheel plate must be kept well lubricated with chassis grease to prevent friction and binding between the tractor fifth wheel plate and the trailer. For lubrication instructions, see Group 31 of the Columbia® Maintenance Manual .

Fontaine Fifth Wheels

General Information

The Fontaine sliding fifth wheel mount is designed to provide optimum axle loading for maximum tractor use with different lengths and types of trailers. The sliding fifth wheel mount is used with the Fontaine H5092 series fifth wheel and the Fontaine 6000/7000 No-Slack II series, and is equipped with either an air-operated release slide (HAWB or AWB model), or a manual release slide (HMWS or MWS model).

On Fontaine fifth wheels, kingpin release is accomplished by activating a manual lock control handle located on either the right side or left side of the fifth wheel. Kingpin lockup occurs when the kingpin is forced into the jaws and the lock control handle moves to the locked position.

The fifth wheel top plate is mounted on a slide assembly, which is attached to slide rails that are mounted on the vehicle frame. The slide rails permit forward and rearward movement of the slide assembly, allowing for optimum weight distribution over the tractor axles.

Slots are evenly spaced along the slide rails, and retractable tapered wedges are positioned through the slots to hold the fifth wheel in the desired position. See Fig. 10.14 or Fig. 10.15 .

1. Locking Wedge
2. Air Cylinder

Fig. 10.14, Air-Operated Sliding Fifth Wheel Mount, AWB Model

1. Locking Wedge
2. Slide Release Pull Handle

Fig. 10.15, Manual Release Sliding Fifth Wheel Mount, MWS Model

The slide portion of the sliding model may be attached to either an air-operated release slide, or a manual release slide.

The air-operated release slide contains an air cylinder that locks and unlocks the fifth wheel slide. See Fig. 10.14 . The air cylinder is activated by a two-position air-control valve in the tractor cab.

The manual release slide contains a slide release pull handle, located on the left side of the fifth wheel, which locks or unlocks the fifth wheel slide. See Fig. 10.15 .

Fifth Wheel Lock Mechanism for Trailer Kingpin

The Fontaine fifth wheel lock mechanism for the trailer kingpin ( Fig. 10.16 ) consists of a spring-loaded jaw and a sliding wedge.

A. Unlocked Position
B. Locking
C. Locked

1. Wedge
2. Jaw
3. Trailer Kingpin

Fig. 10.16, Fontaine Kingpin Lock Mechanism

The jaw and wedge each have a pin permanently attached. The pin on the jaw and the pin on the wedge fit into elongated notches in the lock control handle. The notches in the handle control the limit of movement for both the jaw and wedge. The notches are arranged so that the wedge is actuated first during release of the kingpin.

During lockup, the jaw is moved first with the spring-loaded wedge being allowed to slip in place against the jaw. A timing bracket ensures that the wedge and jaw are moved at the proper time.

Placing the lock control handle in the unlocked position moves the wedge away from the jaw. This action unlocks the jaw so that it can be moved by the trailer kingpin. When the tractor is moved out from under the trailer, the kingpin moves the jaw until the kingpin is out of the mechanism. With the jaw in the unlocked position, the lock control handle will remain in the unlocked position until manually moved by the operator.

During coupling ( Fig. 10.16 ), the motion of the kingpin entering the jaw will actuate the jaw and wedge. The jaw will move behind the kingpin, followed by the wedge. The purpose of the wedge is to reinforce the jaw and take up slack around the pin. Any wear on the jaw is immediately taken up by the wedge so there is no slack in the connection.

Fifth Wheel Locking Operation

Locking the Fifth Wheel Lock Mechanism

Before attempting to lock or unlock the fifth wheel lock mechanism of a sliding type fifth wheel, the slide release pull handle, if so equipped, and the slide locking wedges must be in the locked position. This prevents the sliding member from moving rapidly to the far forward or rearward position, which could damage the fifth wheel member or kingpin.

Chock the front and rear of the trailer tires to prevent the trailer from moving.

The kingpin lock mechanism must be fully open, the fifth wheel plate must be completely lubricated with chassis grease. For lubrication instructions, see Group 31 of the Columbia® Maintenance Manual .

Position the tractor so that the fifth wheel lock opening is in line (both vertically and horizontally) with the trailer kingpin. The kingpin should be in a position to enter the throat of the locking mechanism ( Fig. 10.16 ). Adjust the trailer landing gear to give enough alignment height for positive kingpin lockup.

Apply the tractor parking brakes.

Make a visual and physical check for positive kingpin lockup. When lockup has occurred, the fifth wheel control handle will have moved to the locked position. Make sure that the safety latch is down over the lock control handle. See Fig. 10.17 . This will hold the control handle in the locked position.

NOTE: Make sure the safety latch is down when the control handle is locked.

A. Unlocked
B. Locked

1. Safety Latch
2. Lock Control Handle

Fig. 10.17, Fontaine Fifth Wheel, Locking and Unlocking

Release the tractor parking brakes. Test for kingpin lockup by pulling on the trailer against the chocks.

NOTICE

After lockup is completed, connect the tractor-to-trailer air system lines and the electrical cable to the trailer. Take care to prevent dirt or foreign material from entering the air system lines.

Charge the air brake system with air. Make sure that the air connections do not leak.

Incorrect fifth wheel lock adjustment could cause the trailer to disconnect, possibly resulting in serious personal injury or death.

10.

For adjustment instructions, refer to the applicable manufacturer's service information.

11.

Retract the trailer landing gear, and secure the ratchet handle. Remove the chocks from the trailer tires.

12.

The load distribution on the front steering axle and rear drive axle(s) will have a direct effect on the steering control of the vehicle.

12.

Determine the front and rear axle weights by weighing the vehicle on scales designed for this purpose.

12.

The maximum axle weight ratings are given on the Federal Motor Vehicle Safety Standard (FMVSS) label or Canadian Motor Vehicle Safety Standard (CMVSS) label attached to the left rear door post of the tractor. The desired load on the axle is no less than 80 percent of the maximum axle weight rating, but in no instances should the axle load exceed the maximum axle weight rating given on the FMVSS or CMVSS label.

Do not overload any tractor axle by improperly loading the trailer. This could cause erratic steering and loss of vehicle control, possibly resulting in serious personal injury or death.

Unlocking the Fifth Wheel Lock Mechanism

Apply the tractor parking brakes.

Pull the trailer air supply valve to cut off the air supply to the trailer.

Chock the front and rear of the trailer tires to prevent the trailer from moving.

Lower the trailer landing gear until the weight is removed from the fifth wheel.

Disconnect the tractor-to-trailer air system lines and electrical cable. Plug the air lines to prevent dirt or foreign material from entering the lines.

Release the kingpin locking mechanism by lifting the safety latch and pulling the lock control handle to the unlocked position. See Fig. 10.17 .

Slowly drive the tractor away from the trailer.

Fifth Wheel Slide Operation

Connect the trailer kingpin to the tractor fifth wheel. For instructions, refer to Fontaine "Fifth Wheel Locking Operation," in this chapter.

After positive lockup of the fifth wheel lock mechanism has been accomplished, release the slide using one of the following methods:

2.1

For air-operated release models, set the cab-operated control switch ( Fig. 10.18 ) to UNLOCK.

Fig. 10.18, Cab Control, Fifth Wheel Slide

Fig. 10.19, Fontaine Sliding Fifth Wheel Manual Release

2.2

For manual release models, lift the slide release pull handle to disengage it from the guide plate. Then, pull out the handle ( Fig. 10.19 ) until it is in the unlocked position and can be positioned against the guide plate to hold it out. The slide release pull handle will stay in the unlocked position until it is manually disengaged from the guide plate.

Lower the trailer landing gear just enough to remove the weight from the tractor.

Pull the trailer air supply valve to cut off the air supply to the trailer.

Chock the front and rear of the trailer tires to prevent the trailer from moving.

Slowly move the tractor forward or backward until the fifth wheel is in the desired location.

Apply the tractor parking brakes.

NOTE: The fifth wheel may have to be moved slightly to enable the locking wedges to enter the fully locked position.

Lock the sliding member in position using one of the following methods:

Check that the locking wedges have seated in the slots. Failure to achieve complete lockup may allow disengagement of the tractor from the trailer, possibly resulting in serious personal injury or death.

8.1

For air-operated release models, set the cab-operated slide control switch to LOCK. Visually inspect the locking wedges to make sure that they are fully inserted in the slide rail slots.

8.2

For manual release models, disengage the slide release pull handle from the guide plate. The slide release pull handle is spring-loaded in the locked position and will seek the locked position when disengaged from the guide plate. The fifth wheel may have to be moved slightly to enable the locking wedges to fully enter the locked position. When the slide release pull handle returns to the fully locked position, visually and physically check the locking wedges to make sure they are fully inserted into the slots in the slide rails. Make sure the slide release pull handle is locked in position against the guide plate.

The amount of load distribution on the front steering axle and rear drive axle(s) will have a direct effect on the steering control of the vehicle.

Determine the front and rear axle weights by weighing the vehicle on scales designed for this purpose.

Fifth Wheel Lubrication

For lubrication instructions, see Group 31 of the Columbia®Maintenance Manual .

Premier Trailer Couplings

General Information

IMPORTANT: Before operating the Premier coupling, refer to the Premier web site atwww.premier-mfg.comfor complete safety, operation, and maintenance instructions.

Trailer couplings, used only on trucks, are attached to the rear closing crossmember.

The Premier 260 and 460 trailer couplings ( Fig. 10.20 ) have a rigid pintle hook, and are air-adjusted. An air chamber, mounted forward of the coupling, operates a pushrod, which pushes against a shoe inside the coupling. The shoe maintains constant pressure on the eye of the trailer drawbar when it's over the pintle hook. This takes up any slack in the trailer connection, providing smoother towing and less wear on the pintle hook. The air pressure is activated when the trailer brakes are released.

A. Model 260
B. Model 460

1. Pintle Hook
2. Latch
3. Pawl Assembly
4. Pawl Lock
5. Pawl Wedge
6. Shoe

Fig. 10.20, Premier 260 and 460 Trailer Couplings

The Premier 690 trailer coupling ( Fig. 10.21 ) has a moveable pintle hook, and is non-air adjusted. It is used for heavy-duty applications.

1. Linch Pin
2. Handle
3. Pintle Hook
4. 294 Bolt

Fig. 10.21, Premier 690 Trailer Coupling

Operation

If at any time the 690 coupling is bound up (jackknifed), the 294 bolt MUST be replaced immediately! Do not use the coupling until the bolt has been replaced. In addition, carefully inspect the 690 coupling, drawbar, drawbar eye, front end assembly, and tail board for damage. Failure to do so may result in trailer separation from the truck while in use, resulting in serious personal injury or property damage.

Trailer Hookup

Chock the front and rear tires of the trailer.

Open the coupling.

Models 260 and 460 ( Fig. 10.20 ): Pull up on the pawl lock; then, while squeezing the pawl wedges together, lift up the pawl assembly. Lift up the latch, and push it up against the pawl assembly, locking the latch in place.

Model 690 ( Fig. 10.21 ): Remove the linch pin from the handle, then push in on the handle and turn it toward you. Open the pintle hook by pulling it down and toward you. Release the handle, locking the pintle hook open.

Models 260 and 460: Back up the vehicle until the drawbar eye is over the pintle hook, then lower the trailer.

Model 690: Back up the vehicle until the drawbar eye enters the open jaw, contacts the back of the pintle hook, and closes the coupling.

Close the coupling.

Models 260 and 460: Push in on the pawl wedges and lift the pawl assembly. The latch will drop into the closed position. Lock the latch by lowering the pawl assembly.

Model 690: The pintle hook will automatically close and lock from the pressure of the drawbar eye against it. Install the linch pin.

NOTICE

Hook up the trailer's electrical and air lines.

Remove the chocks from the trailer's tires.

Trailer Release

Apply the truck and trailer parking brakes.

Chock the front and rear tires of the trailer.

Disconnect the trailer air and electrical lines. Plug the air lines to keep out dirt.

Take the weight of the trailer drawbar eye off the pintle hook.

Open the coupling.

Models 260 and 460: Pull up on the pawl lock; then, while squeezing the pawl wedges together, lift up the pawl assembly. Lift up the latch, and push it up against the pawl, locking the latch in place.

Model 690: Remove the linch pin from the handle, then push in on the handle and turn it toward you. Open the pintle hook by pulling it down and toward you. Release the handle, locking the pintle hook open.

Slowly drive the vehicle away from the trailer.

Holland Trailer Coupling

General Information

The Holland PH–T–60–AL trailer coupling is designed for use with trailers having a maximum gross weight of 10,000 lbs. See Fig. 10.22 . It is a rigid type pintle hook, used only on truck applications, and is fastened to the rear closing crossmember of the vehicle. It is a non-air adjusted coupling.

1. Lock
2. Cotter Pin
3. Latch
4. Pintle Hook

Fig. 10.22, Holland PH-T-60-AL Trailer Coupling

Operation

Trailer Hookup

Chock the front and rear tires of the trailer.

Remove the cotter pin, then lift the lock and raise the latch.

Back up the vehicle until the drawbar eye is over the pintle hook.

Lower the trailer until the drawbar eye rests on the pintle hook.

Close the latch, then insert the cotter pin.

NOTICE

Hook up the trailer's electrical and air lines.

Remove the chocks from the trailer's tires.

Trailer Release

Apply the truck and trailer parking brakes.

Chock the front and rear tires of the trailer.

Disconnect the trailer air and electrical lines. Plug the air lines to keep out dirt.

Take the weight of the trailer drawbar off the pintle hook.

Open the latch by first removing the cotter pin; then lift up the lock and raise the latch.

Slowly drive the vehicle away from the trailer.