Husky 33310 User manual

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Assembly, Installation, Operation and
Maintenance Instructions
CENTER LINE FS SYSTEM
33310: CENTER LINE FS, 400-600 LBS. W/2-5/16” BALL
33311: CENTER LINE FS, 600-800 LBS. W/2-5/16” BALL
33312: CENTER LINE FS, 800-1200 LBS. W/2-5/16” BALL
INSTALL TIME:
0.5-1 HOUR
Dealer / Installer: Provide a copy of these instructions to the end user of this product. These
instructions provide important operating and safety information for proper usage
of this product. Demonstrate the proper use of the product with the end user.
Have the end user demonstrate that they understand the proper use of the
product.
End User: Read and follow all instructions included in this manual. Ask your Dealer / Installer
for assistance if you do not understand the proper use of the product. Never
remove any decals from the product. Failure to follow these instructions can result
in injury or death.
WARNING
DO NOT EXCEED RECOMMENDED TOWING LIMITS. SEE VEHICLE’S OWNER’S
MANUAL.
Rating when used as a weight distribution hitch with spring bars
CAUTION: The tongue weight rating of spring bars represents the capacity of a pair of bars,
NOT an individual bar
Part Number Max. Tongue Weight Max. Gross Trailer Weight
33310, 33311, & 33312 600 lbs. / 272 kg. 6,000 lbs. / 2721 kg.
Always use a pair of spring bars and be sure they are of the same weight rating and size for your trailer.
READ ALL INSTRUCTIONS AND CHECK PACKAGE CONTENTS BEFORE BEGINNING INSTALLATION.
Note: This system can be used on any angle tongue trailer.
Part Number Max. Tongue Weight Max. Gross Trailer Weight
33310 400-600 lbs. / 181-272 kg. 6,000 lbs. / 2721 kg.
33311 600-800 lbs. / 272-363 kg. 8,000 lbs. / 3629 kg.
33312 800-1200 lbs. / 363-544 kg. 12,000 lbs. / 5443 kg.
WARNING
Use ONLY with 4”, 5”, 6”, 7” & 8” trailer frames.
WARNING
Rating when used as a weight carrying hitch without spring bars

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Tools Required for Installation
The following list of tools will be needed for proper installation of all components:
•Safety Glasses
•15/16" Open End Wrench (5/8” HEX NUT)
•1-1/8” Box End Wrench (3/4” HEX HEAD BOLTS)
•1-1/16” Socket (3/4” HEX NUTS)
•3/4” Socket (1/2” HEX NUTS)
•½” Ratchet
•Measuring Tape
•Torque Wrench capable of 380 ft-lbs. of torque
•1-7/8” Thin-Walled Socket (1-1/4” HITCH BALL NUT) – REQUIRED ONLY IF REMOVING OR
TIGHTENING THE HITCH BALL
Recommended tools for installing the Hitch Ball:
None are required as the hitch ball comes from the factory pre-installed. It is recommended that you
check the torque of the hitch ball nut periodically using a 1-7/8” Thin-walled socket depending on hitch
ball size.
Torque Wrench capable of 380 ft-lbs. of torque (always check ball manufacturer’s specifications for
proper torque rating)
Important!
Before installing or towing with this Bolt Together Weight Distributing Hitch please read and
follow all instructions and warnings in the tow vehicle owner’s manual and trailer owner's
manual.
Have gross trailer weight and tongue weight checked before selecting and installing any weight
distributing system.
Weigh trailer again after fully loading and check loaded tongue and gross weight to ensure
proper weight distribution hitch is being used.
These instructions are guidelines only. Actual installation is the responsibility of the installer and the
owner. Always measure truck and trailer before installing hitch to be sure that there is clearance at the
bumper to allow for turns.
This kit is to ONLY be used with Husky weight distribution spring bars only that are designed for
this particular system. Do not substitute with any other spring bars.
Do not use a separate friction sway control on this unit!
WARNING
WARNING
WARNING

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Measure Trailer Coupler & Frame Height
NOTE: Changing the weight of the trailer and/or tow vehicle by adding, moving or unloading cargo
may require the need to adjust how the weight distribution system is set up.
IMPORTANT! Set parking brake of tow vehicle and chock the wheels of the trailer before lifting or
lowering!
1. Line up the tow vehicle and trailer on level pavement, in a straight position.
2. Use the trailer tongue jack to level the trailer. Measure the distance from pavement to the inside of
the coupler socket, and record here:_______________
3. Mark a spot on the side of the frame on the trailer as close to the coupler as you can. Measure from
this mark to the pavement, and record here: ______________. This measurement will be used later
to determine if a proper setup has been achieved.

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Measure the Tow Vehicle
For vehicles with air springs, air shocks or automatic leveling systems only: Check vehicle owner's
manual or other instructions on these items. Unless otherwise indicated, air springs and air shocks
should be deflated to their minimum recommended pressure BEFORE assembling and adjusting the
weight distribution hitch. Pick reference points at the top center of the front and rear fender well of
towing vehicle. Measure and record the height to pavement here:
FRONT FENDER TO PAVEMENT:
REAR FENDER TO PAVEMENT:
ILLUSTRATION 3
Installation and Setup
NOTE: To obtain proper ball height on low ground clearance tow vehicles, shank may be oriented in the
“UPRIGHT POSTION” as shown in Illustration 4. If shank is used in the “INVERTED POSITION, check
shank for adequate ground clearance. Accessory shanks with greater height and length are available
from your dealer. IMPORTANT! Proper adjustment requires the use of the proper length shank
and proper head height.
ILLUSTRATION 4

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4. Un-screw the 5/8-11 hex bolt until the bottom of the bolt threads are flush to the inside of the
channel.
5. Insert the shank into the receiver box. Hold the Center Line FS head assembly on the shank as
shown and align so that the hitch ball is 1" above the coupler socket.
5/8-11 HEX HEAD BOLT
ILLUSTRATION 5
ILLUSTRATION 6
In this example, the shank is
mounted in the Upright Position (as
shown). And the bottom 3/4” hex bolt
will pass through the 2nd hole from the
bottom on the shank. If needed, the
shank can be in the Inverted Position
(see page 4) to achieve the proper ball
height.
Shank in Upright Position

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6. Align the bottom hole on the channel to the hole on the shank. Place a ¾” washer onto the ¾” hex
bolt. Then insert the bolt with washer through the bottom hole in the channel and through the
shank. Remember the hole and orientation in these instructions are an example only, yours
may be different.
7. Place a ¾” washer onto the other ¾” hex bolt, then insert the bolt through the top hole in the
channel and through the shank.
ILLUSTRATION 8
ILLUSTRATION 7
¾” Washer and ¾” Hex Bolt
¾” Washer and ¾” Hex Bolt

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8. The use of shims may be required to fill up the gap between the U channel and the shank. It
is NOT necessary to have equal shims on either side.
9. Tighten 5/8” hex bolt securely. Torque the 5/8” bolt to 50ft.lbs. Then, securely tighten the 5/8” jam
nut.
5/8” hex jam nut & Washer
5/8” hex bolt
U channel
Shim
ILLUSTRATION 9
ILLUSTRATION 10

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10. Put a ¾” flat washer on the top ¾” hex bolt followed by a ¾” nylon lock nut. Put a ¾” flat
washer on the bottom 3/4” hex bolt followed by a ¾” nylon lock nut. Torque the ¾” nylon
lock nuts to 260 ft-lbs.
11.Insert a spring bar into the tube. Secure with the “D”-pin. Swing wire “D” around the tube
and over the end of the pin. Repeat for the other side.
BE SURE THAT THE “D” RETAINING PIN GOES THROUGH GROOVE IN THE SPRING
BAR. PULL DOWN ON SPRING BARS TO TEST FOR PROPER ATTACHMENT.
¾ Nylon Lock Nut
¾ Flat Washer
Spring Bar
“D”-Pin
ILLUSTRATION 11
ILLUSTRATION 12

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12. Your Center Line FS system should look like this now.
Installing Frame Brackets
13. Remove L-Pin, tether, and hair pin from the lift bracket. Remove the 1/2” hex flange bolts so the
lift bracket can be removed from the frame bracket.
½” Hex Flange Bolts
Lift Bracket
Frame Bracket
Tether
L-Pin
Hair Pin
ILLUSTRATION 13
ILLUSTRATION 14

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28.5” – 30.5”
14. Install both frame brackets and frame plates 28.5”-30.5” away from the center of ball socket on
coupler on each side of the trailer frame. See Step 15 for frame bracket and plate assembly.
Frame brackets mount on the outside of the frame. Frame plates mount to inside of the frame.
15. Use the 1/2" carriage bolt, flat washer, lock washer and hex nut to hold the frame brackets in place
using the top hole. Use the 1/2" carriage bolt, flat washer, flat washer with tether, lock washer and
hex nut to hold the frame brackets and frame plates in place through the hole closest to the
underside of the trailer frame. Tighten all (4) 1/2" carriage bolts to 45-55 ft. - lbs.
½” FLAT WASHER
½” HEX NUT
½” LOCK WASHER
FLAT WASHER WITH
TETHER BETWEEN LOCK
WASHER AND FLAT
WASHER
INSIDE VIEW OF
FRAME BRACKET
ASSEMBLY
OUTSIDE VIEW OF
FRAME BRACKET
ASSEMBLY
TOP BOLT ASSEMBLY
WITHOUT TETHER
BOTTOM BOLT
ASSEMBLY
WITH TETHER
CARRIAGE
BOLT
TRAILER FRAME
FRAME BRACKET
FRAME BRACKET
FRAME PLATE
ILLUSTRATION 15
ILLUSTRATION 16