Curt Manufacturing 16600 User manual

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 1
INSTALLATION MANUAL 16600
Tools Required
Ratchet Torque wrench
Socket set --
Product Photo
Torque Specifications
1/2" bolt 65 ft-lbs.
M20 bolt 300 ft-lbs.
Use above torque setting unless otherwise noted
Product Registration
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industry-leading warranties. Provide
feedback and help us to improve our
products by registering your purchase at:
warranty.curtgroup.com/surveys
Level of Difficulty
Moderate
DANGER ZONE PRECAUTIONS
Block all trailer tires in front and behind with appropriate wheel chocks. Do not
substitute objects such as, but not limited to: stones, wood blocks, etc. Front
trailer lifting jacks must be supporting the trailer and resting on a firm and level surface.
Towing vehicle must be stationary with automatic transmission
in park (manual in neutral), emergency brake applied and engine off.
Parts List
Item Qty Description
1 1 Base weldment
2 1 Upper weldment
3 1 Lower coupler assembly
4 1 Lube plate
5 2 Hex head cap screw, 1/2"
6 2 Nylock nut, 1/2"
7 1 Bushing
8 1 Hex bolt, M20
9 1 Nylock nut, M20
10 1Flat washer, M20
11 4Spacer, 0.094"
12 4Base rail mounting clip
13 4Base rail mounting pin, 1/2"
Weight Capacity
Gross trailer weight (GTW) 20,000 lbs.
Vertical load 5,000 lbs.
NOTICE
Before you begin installation,
read all instructions thoroughly.
Proper tools will improve the quality of
installation and reduce the time required.
To help prevent damage to the product
or vehicle, refer to the specified torque
specifications when securing hardware
during the installation process.
WARNING
Fully instruct and demonstrate the operation of this 5th wheel hitch to the end user. Include the
importance of observing all warnings contained herein, including warning labels on 5th wheel
hitch main body. Provide this manual in its entirety to the end user. Serious injury or death may
result if the warnings above are not observed.
Do not expose hands, body parts or clothing between the truck and
trailer or the truck's bed sides and trailer. If you must place any part
of your body under trailer or between truck and trailer, you must:
1. Block all trailer tires with wheel chocks.
2. Make sure trailer landing gear / jacks are resting on a firm, level surface.
3. Towing vehicle must be stationary with auto transmission in park
(manual in neutral), emergency brake applied and engine off.
Never exceed the towing capacity (trailer and contents combined)
of any towing system component or your vehicle.
Improperly coupled trailers can separate or drop without notice,
causing serious injury or death. To reduce the chance of serious injury or death:
Never attempt to couple trailer without reading and following all instructions thoroughly.
Always follow operating instructions to secure trailer to tow vehicle.
Make sure the hitch is secure before towing.
Prior to towing, ensure all components and hardware are structurally sound and secure.
Always chock the trailer to prevent movement while coupling the hitch.
Always ensure lynch pins are installed through handle before towing.
Always perform a pull test prior to towing. See 'pull test' later in this instruction manual.
Never position anyone under the trailer's kingpin area during coupling and uncoupling.

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 2
Step 3
Measure from the ground to the surface of the truck bed rails.
Subtract the measurement taken in Step 2 from Step 1.
This value will be near the height requirement for the 5th wheel.
16-3/8" -
20-3/8"
2
11
10
12
13
Before you begin
Assembly includes measuring the height requirement for the 5th
wheel head in relation to the trailer ride height at the kingpin box and
skid plate. Ideally, the trailer should ride as near to level as possible.
The 5th wheel is adjustable from 16-3/8" to 20-3/8", from
the truck bed rails to the top of its skid plate. Adjustment is
attained by adjusting the lower coupler assembly up or down,
in relation to the legs, in 2" increments (typical clearance
between the truck bed rails and the trailer should be a
minimum of 5-1/2"). Follow the steps below to measure.
Step 1
With the trailer on a firm and level surface, set chock blocks
in front of and behind the tires. Do not substitute wood blocks,
rocks, etc. for chock blocks. Extend front trailer lifting jacks,
adjust as required to set trailer at or near level.
Step 2
Measure from the ground to under the trailer's kingpin
box skid plate or lube plate, if used. This will be the portion
in contact with the 5th wheel's skid plate once coupled.
ASSEMBLY
CALCULATING HEIGHT
MAIN BODY ASSEMBLY
Before you begin
Once you have determined the height adjustment required for
the 5th wheel, assemble the lower coupler assembly to the base
weldment using the appropriate holes. Occasionally, the trailer's
kingpin pin box will require adjustment to facilitate correct ride height.
3
4
5
871
9
6
Parts List
Item Qty Description
1 1 Base weldment
2 1 Upper weldment
3 1 Lower coupler assembly
4 1 Lube plate
5 2 Hex bolt, 1/2"
6 2 Nylock nut, 1/2"
7 1 Bushing
8 1 Hex head cap screw, M20
9 1 Nylock nut, M20
10 1Flat washer, M20
11 4Spacer, 0.094"
12 4Base rail mounting clip
13 4Base rail mounting pin, 1/2"

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 3
Step 3 - Mount to the Base Rails
With the base rails correctly positioned, the 5th wheel will drop into
the slots on the top surface of the base rails. Align the four tabs on
the bottom of the 5th wheel legs with the corresponding slots in the
tow vehicle's base rails.
Lower the 5th wheel into the rails. Secure with four 1/2" rail mount
pins & clips (#12, #13) as illustrated in the diagrams below. If desired,
the neoprene spacers (#11) can be used between the hitch and the
rails to reduce clanking and rattling.
A
If installing new base rails, follow the instructions provided by the rail
manufacturer for proper placement, alignment and spacing per your
vehicle's year, make and model. If the 5th wheel is being mounted to
existing base rails, and alignment issues arise, it may be necessary
to proceed as follows:
Loosen the base rail bolts and realign the base rails to
facilitate installation. It is recommended to replace old
lock washers with new lock washers at this time. Torque
the base rail bolts to the rail manufacturer's specifications.
Step 1 - Lower Coupler Attachment
Attach lower coupler assembly (#3) to base weldment (#1) using the
fasteners shown (#7, #8, #9, #10) in the height position determined in
the previous steps. Make sure the bushing is installed as shown and is
toward the rear of the vehicle. Torque 20mm bolt and nut to 300 ft-lbs.
Step 2 - Check the Base Rails
Before attaching the 5th wheel hitch to the tow vehicle's base
rails, check the base rails in your truck to be sure they are properly
installed and are parallel with each other. The diagonal dimensions
should be the same, see diagram below.
MAIN BODY ASSEMBLY (CONT)
3
7 (bushing)
9
1
10
13
12
8
Ensure rail kits are installed
according to rail kit manufacturer's
recommended specifications
Each base rail must have a bolt
in either of the marked holes. Check
for obstructions before drilling
Measure diagonal from
same reference point.
Distances should be equal
Rear edge of truck bed
to rear edge of base rail
Front of truck
Rear edge of truck bed
Detail A
Front of
vehicle

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 4
Step 1
Place upper weldment (#2) and lube plate (#4) as shown,
on trailer king pin. While holding the upper weldment tight
against the pin box, insert two 1/2" hex bolts (#5) through
the upper weldment and secure with 1/2" nylock nuts (#6).
UPPER COUPLER INSTALLATION
4
2
5
6
Step 2
Torque the 1/2" hex bolts and nuts to 65 ft-lbs.
Step 3
Make sure the the upper weldment (#2)
spins freely around the king pin.

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 5
COUPLING & LOCKING
Preparing the vehicle and trailer to couple
It is advised to perform trailer connections to the 5th wheel
on a firm and level surface. Multiple wheel chocks should
be used in front of and behind the trailer tires. Do not substitute
objects such as, but not limited to: stones, wood blocks, etc.
Open or remove tailgate as required to safely back the tow vehicle
under the trailer and center the trailer coupler with the opening on
the hitch head. Stop the tow vehicle when the trailer's coupler is
approximately 2" from the coupler on the fifth wheel trailer.
Ensure the trailer wheels are chocked and proceed
to raise or lower the trailer jacks to position the
coupler 1" above the hitch head as shown.
2"
1"
Step 3 - Coupling & Locking
Remove the safety pin on the 5th wheel's handle.
Push handle in and turn counterclockwise until rotation
stops. Then pull handle completely out to allow coupling.
Back the tow vehicle the rest of the way slowly until trailer coupler
contacts face of hitch. Set the parking brake and raise the jacks
on the trailer until trailer coupler has seated fully into hitch coupler
(if coupler does not seat fully, the vehicle might need to be moved
slightly forward to relieve tension on the hitch)
Push the hitch handle in and turn clockwise to the locked
position and re-insert the safety pin. Check to make sure handle
is fully inserted and safety pin is in place prior to performing
pull test, raising camper jacks fully and removing wheel chocks.
Step 1 - Preparing the 5th wheel to couple
Check for any signs of damage to the locking mechanism.
If any of components are missing or damaged, do not
attempt to use the hitch until it has been repaired.
Check to make sure 20mm bolt holding the lower coupler
assembly to the base is not loose if needed re-torque to 300 ft-lbs.
Step 2 - Preparing the 5th wheel to couple
Ensure the locking mechanism is free of excessive dirt, rust, grease,
snow, ice or other foreign material preventing it from cycling properly.
Clean excessive dirt, snow or ice with warm soap water. Lightly
lubricate exposed surfaces with a rust inhibitor to restore proper
operation. Components with excessive amounts of rust may require
replacement to restore proper functionality.
WARNING
Never position yourself or others under the trailer's kingpin area
(danger zone) during coupling and uncoupling. If for any reason, you
must position any part of your body under the trailer or between the
truck and trailer or between the trailer kingpin and 5th wheel hitch,
you must follow the steps in the 'Danger Zone Precautions' on page 1.

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 6
UNCOUPLING & RESETTING
Step 1
Park on a firm and level surface. Set automatic transmission
vehicles to park and activate emergency brake. Set standard
transmission vehicles to neutral and activate emergency brake.
Chock the trailer wheels. Multiple wheel
chocks should be used, both in front and
behind the tires. Do not substitute objects
such as stones, wood blocks, etc.
Disconnect all harnesses, lanyards, safety
devices, etc. as required to separate the
trailer from the tow vehicle. Lower or
remove truck tailgate as required.
Begin extending the front trailer lifting
jacks. The lifting jacks should be extended
just enough to remove the weight of the
trailer from the 5th wheel skid plate.
Note: Do not lift rear of vehicle with trailer jacks
as this will make it difficult to pull handle out.
Step 2
Remove the safety pin on the 5th wheel's handle.
Push handle in and turn counterclockwise until
rotation stops. Then pull handle completely out.
Lower jacks until trailer coupler clears hitch coupler.
Step 3
Remove the parking brake and slowly drive the tow vehicle
out from under the trailer. If resistance is encountered,
determine the corrective action and repeat uncoupling steps.
Preparing to tow
Confirm handle safety latch pin has been installed.
Attach electrical harnesses.
Attach lanyard and insert electric brake break-away
plunger. If hydraulic surge brakes are present, attach
lanyard from the surge brake assembly as required.
Fully retract front trailer lifting jacks.
Close truck tailgate or reinstall tailgate as required.
Remove tire chock blocks.
Check running lights, directional signals
and brake lights for proper operation.
Pull forward a few feet and apply brakes to check that trailer brakes
are activating. Adjust the electric brake controller if necessary.
Pull test
After coupling and prior to removing trailer wheel blocks
and / or raising front trailer jacks, you must do the following.
Set towing vehicle in a forward gear and lightly tug on the
trailer to ensure that 100% coupling has taken place. If
resistance is felt, release forward pressure, set vehicle
to park (if equipped with an automatic transmission) and
activate the emergency brake. Place in neutral if equipped
with a standard transmission and activate emergency brake.
If resistance is not felt, trailer may not be coupled correctly.
Do not continue applying forward pressure, immediately stop
and back towing vehicle into original position. Do not allow
the truck and trailer to separate. Separation can cause damage
to the towing vehicle, 5th wheel hitch and / or trailer. Serious
injury or death may result if all warnings are not observed.
Review coupling instructions, apply
corrective action and repeat coupling steps.
COUPLING & LOCKING (CONT)

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 7
REMOVE & REINSTALL
Removal
To remove the entire 5th wheel hitch from
the base rails, follow the steps and diagram below.
1. Remove the base rail pins & clips.
2. Remove the 5th wheel unit from the base rails.
Re-installation
Reinstall the 5th wheel in the reverse order it was removed.

CURTMFG.COM •PRODUCT SUPPORT: 877.287.8634 •16600-INS-RA •12/08/2021 •ECN9081 •PAGE 8
Maintenance
The CURT 5th wheel hitch has been designed to offer years of safe and reliable service.
To achieve the best performance and the longest possible service life, please follow the maintenance schedule below.
A
5
6
4
22
4
1
3
Component Frequency Instructions
Inspect lube plate Before each use and
every 1,000 miles
Inspect the condition of the lube plate (#1). If worn replace with (CURT# 16722)
Lubricate the
head pivot point
Before each use spray light dry film lubricant (#2)
Torque the
1/2" bolts
Every 1,000 miles Torque the two 1/2" hex bolts (#3) to 65 ft-lbs.
Re-torque after initial 500 miles and every 1,000 miles thereafter.
Handle pin Before each use spray light dry film lubricant (#4)
Torque lower
M20 bolt
Before each use and
every 1,000 miles
Torque lower bolt to 300 ft-lbs (#5)
Clean the
5th wheel hitch
After each
use and before
long term storage
For optimal service life, clean your 5th wheel hitch after each use with warm soapy water
and dry with towels or compressed air. It is also recommended that the 5th wheel is removed
from the vehicle or covered when not in use for extended periods of time. Spray exposed
surfaces with a light coat of rust inhibitor before long term storage.
MAINTENANCE
WARNING
Do not torque upper M20 head pivot bolt (#6) nut is designed to only make contact but not apply clamping force. If bolt is torqued
it could cause bolt to fail causing hitch separation during use leading to severe injury or death. If hitch head appears loose the
20mm bolt can be removed and inspected for damage if any cracks or damage is visible immediately discontinue use of hitch.