FEBRUARY 2014
WEIGHT DISTRIBUTION SYSTEM
INSTALLATION INSTRUCTIONS
RATING WHEN USED AS A WEIGHT DISTRIBUTION HITCH WITH SPRING BARS:
PART NUMBER
MAX. BALL WEIGHT
MAX. GROSS TRAILER WEIGHT
MHWDR6
135 - 275 kg
3500 kg
MHWDR8
227 - 365 kg
3500 kg
RATING WHEN USED AS A WEIGHT CARRYING HITCH WITHOUT SPRING BARS:
PART NUMBER
MHWDR6
MHWDR8
MAX. BALL WEIGHT
275 kg
MAX. GROSS TRAILER WEIGHT
2750 kg
BALL WEIGHT is the weight on the front of the trailer that is not carried over the trailers axles. You
should aim to have a ball weight which is 10% of your gross trailer weight. Doing so will help keep the
trailer stable and easy to handle. GROSS TRAILER WEIGHT is the weight of the trailer when it is fully
loaded.
YOUR GROSS TRAILER WEIGHT AND BALL WEIGHT SHOULD NEVER EXCEED
THE LOWEST RATINGS OF ANY PART OF YOR TOWING SYSTEM.
CAUTION: THE MAXIMUM BALL WEIGHT RATING REPRESENTS THE CAPACITY OF THE FULL SYSTEM
WITH A PAIR OF BARS, NOT AN INDIVIDUAL BAR. ALWAYS USE A PAIR OF APPROVED SPRING BARS
OF THE SAME WEIGHT RATING.
READ ALL INSTRUCTIONS AND CHECK PACKAGE CONTENTS BEFORE BEGINNING INSTALLATION
Never exceed the towing vehicle manufacturer’s load rating.
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PAGE 1
MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM
4
11
13
12
9
15
8
PARTS LIST
5
10
2
2a
6
8
14
16
7
1
17
3a, 3b
18
COMPLETE PARTS LIST
Part
Description
1.
2.
2a.
3a.
3b.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
MHWDS10
MHWDBM
MHWDSR
MHWDSB6
MHWDSB8
MHWDLH
MHWDLB
MHWDCLB
MHWDHP
MHWDRC
MHWDSB
MHWDSN
MHWDSW
MHWDSAP
MHWDSAW
MHWDHB
MHWDLC
MHWDSBU
MHWDSBW
MHWDSBN
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Quantity
Shank Assembly
Head Assembly
Spring Bar Retainer
135-275kg Spring Bar Set
275-365kg Spring Bar Set
Lift Handle
Chain Lift Bracket
1/2” x 3-1/2” Hex Bolt
Hitch Pin
Retainer Clip
3/4” x 4-1/2” Hex Bolt
3/4” Locknut
3/4” Toothed Washer
Pin
Hardened Washer
5/8”-11 x 1-1/2” Hex Bolt
Lift Chain
3/8” U-Bolt
3/8” Flat Washer
3/8” Locknut
(1)
(1)
(2)
(2)
(2)
(1)
(2)
(2)
(1)
(3)
(2)
(2)
(2)
(1)
(7)
(1)
(2)
(2)
(4)
(4)
PAGE 2
MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM
MEASURE TRAILER COUPLING HEIGHT
1. Line up the tow vehicle and trailer on level
ground, in a straight position. Use the trailer
jockey wheel to level the trailer. Measure the
distance from the ground to the top of the
coupling ball socket. See Illustration 2.
RECORD COUPLING HEIGHT HERE _______
ILLUSTRATION 2. TRAILER COUPLING HEIGHT
INSTALLATION INSTRUCTIONS
INSTALL SHANK, HITCH HEAD AND BALL
4. Insert shank (1) into the receiver on towing
vehicle and secure with hitch pin (7) and retainer
clip (8).
NOTE: To obtain proper ball height on high
ground clearance vehicles, shank may be
inverted as shown in Illustration 3. If shank is
used in an inverted position, check for adequate
ground clearance.
ILLUSTRATION 3. SHANK FITTING POSITIONS
TOP OF COUPLING
TO GROUND LEVEL
UPRIGHT
MEASURE THE TOW VEHICLE
NOTE: For vehicles with air springs, air shocks
or automatic leveling systems only: Check
vehicle owners 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.
2. Pick reference points on the front and rear
bumper of towing vehicle. Measure and record
height to the ground.
FRONT BUMPER TO PAVEMENT _________
REAR BUMPER TO PAVEMENT
_________
DETERMINE THE “TARGET” UNCOUPLED
BALL HEIGHT FOR TOW VEHICLE
3. Tow vehicle uncoupled ball height will be set
higher than coupling height measured in Step 1,
to allow for vehicle squat when coupled to trailer.
For cars without overloads, add 3.2mm for each
45kg of ball weight.
RECORD BALL HEIGHT HERE __________
For cars with overloads, trucks or other stiffly
sprung vehicles; add 1.6mm to the height
measured in Step 1, for each 45kg of ball weight.
INVERTED
5. Select a tow ball which matches the trailer
coupling socket, has a 22mm (7/8”) shank and
has a capacity equal to, or exceeding the gross
trailer weight. Tow balls are not supplied with the
hitch. Install the tow ball on the head assembly
(2), but do not tighten at this time.
ONLY USE TOW BALLS THAT MEET
AUSTRALIAN STANDARDS AND/OR
AUSTRALIAN DESIGN RULES (ADR)
6. Position the head assembly (2) on shank.
Slide head up or down to the nearest bolt hole
alignment position which corresponds with the
“TARGET” ball height determined in Step 3.
Mark position on the shank. See Illustration 4.
ILLUSTRATION 4. FINDING HEAD POSITION
MARK POSITION
CLOSEST
POSITION TO
“TARGET”
BALL HEIGHT
GROUND
RECORD BALL HEIGHT HERE __________
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PAGE 3
MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM
7. Place four hardened washers (13) on pin (12)
and insert pin into the unthreaded hole in the
upper portion of the head channel. The number
of washers may have to be changed later.
8. Install head on shank at marked position.
Insert the 3/4" x 4-1/2" hex bolt (9) through the
lower hole in the head channel. Rotate the head
forward as far as it will go. The tow ball should
be vertical or tilted slightly back. If it is not,
change the number of washers (13) on the pin
(12) and re-assemble as before. Insert the
remaining 3/4" x 4-1/2" bolt (9) with toothed
washer (11) through the upper slotted hole.
Install a second toothed washer on the upper
bolt. Start locknuts (10) on to bolts and finger
tighten only. Thread the 5/8” Hex Bolt (14) into
the threaded hole in lower channel of head and
tighten against shank.
9. Tighten top 3/4” x 4-1/2” hex bolt (9) just
enough to hold the head tight against the pin in
the head channel. This bolt will need to be
tightened later.
10. Insert head assembly and shank back into
tow bar receiver on towing vehicle and tighten
the tow ball to torque specified by the ball
manufacturer.
ASSEMBLE, LUBRICATE AND INSTALL
SPRING BARS
1. Assemble the lift chains (15) to the tapered
ends of each spring bar using the 3/8" u-bolts
(16), 3/8” flatwashers (17) and the 3/8" hex
locknuts (18) as shown in Illustration 5 (adjacent
top). Let 2 or 3 threads of the u-bolts extend out
through the bottom of each locknut. The chain
must be free to move in the u-bolt.
INSTALLATION INSTRUCTIONS
ILLUSTRATION 5.
SPRING BAR
AND
LIFT CHAIN ASSEMBLY
15
2-3 THREADS
3a, 3b
16
17
18
ATTACHING TRAILER TO BALL
1. Using the trailer jockey wheel, lower the coupling onto the ball and close coupling latch. Do
not retract the jockey wheel fully at this time.
Allow the jockey wheel to support some of the
ball weight.
2. Raise the front of the trailer and back of the
tow vehicle approximately 75mm (3”) using the
jockey wheel. This will allow easier installation of
the lift brackets.
2. Apply a heavy fibrous grease on the round
end of each spring bar and push end up into
head socket until you hear a click. This will
indicate that the spring bar is locked in place.
NOTE: To release spring bar, lift up slightly on
spring bar and gently pull out on the retaining pin
in the hitch head. The spring bar should drop
free of hitch head.
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PAGE 4
MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM
INSTALLATION INSTRUCTIONS
INSTALLING THE CHAIN LIFT BRACKETS
HOOKING UP THE SPRING BARS
The following directions apply to trailers with "A"
frame drawbars. If your trailer is made up with a
straight drawbar, you will need to obtain a “Boat
Trailer Adapter” to finish the installation.
The amount of leveling is adjusted by engaging
different spring bar chain links with the lift unit.
Before proceeding, read the "LIFT UNIT
OPERATION" section on following page.
1. Position the spring bar, which has been
attached to the head assembly, parallel with the
trailers drawbar. Hold the lift chain vertical up
alongside the trailer drawbar. Position the lift
bracket (5) on the trailer drawbar so that the
chain is centered between the lift bracket as
shown on Illustration 6 below.
1. With the lift bracket in the raised and locked
position, pull straight up firmly on the spring bar
lift chain. Note which link is closest to the lift
bracket hook. Mark the next lower chain link.
CAUTION: If the chain is angled fore or aft at the
top within the lift bracket, it may catch on the
bracket when turning. This could damage the lift
bracket or pry it open.
2. Mark the location of the lift bracket on the
trailer drawbar.
3. Install the 1/2" x 3-1/2" bolt (6) into the
threaded hole in the lift bracket (5). Turn the bolt
in until it contacts the trailer drawbar, then
tighten a 1/4 turn with a wrench.
Do not overtighten.
ILLUSTRATION 6.
2. Lower the lift bracket and slip the marked link
over the hook. Be sure that the chain is not
twisted.
3. Raise the lift bracket and secure with a
retainer clip (8). Repeat procedure on opposite
side of trailer using the same number of chain
links as the first side. See Illustration 7 on the
following page.
4. Retract the trailer jockey wheel so the hitch is
now carrying the full trailer ball weight.
SPRING BAR AND LIFT CHAIN POSITIONING
LIFT BRACKET
TRAILER DRAWBAR
HEAD ASSEMBLY
LIFT CHAIN
SPRING BAR
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PAGE 5
MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM
LIFT BRACKET OPERATION
Before raising or lowering the lift bracket, raise
the front of the trailer to reduce the spring bar
chain tension. This will make the lift bracket
operation easier and safer.
WARNING: Keep clear of the pivot path of all
moving parts when there is tension on the spring
bar chain. Maintain control of the lift handle (4) at
all times when raising or lowering the spring bar.
Be sure that the retainer clip (8) is in place
before leaving lift bracket in the up position.
TO LOWER FROM FULLY RAISED AND
LOCKED POSITION
1. Remove the retainer clip (8) from lift bracket.
2. Insert lift handle (4) onto the rod above the lift
chain attachment.
3. Carefully lower bracket with handle. It will
require effort to bring the bracket over center and
then to resist the chain tension as the bracket
rotates downward.
TO RAISE LIFT BRACKET
1. Slip the marked chain link over hook on lift
bracket.
2. Insert lift handle (4) onto heavier rod above lift
chain attachment.
3. Using the handle, raise the lift bracket up and
over center so that it is fully seated against the
mounting bracket. See Illustration 8.
ILLUSTRATION 7.
INSTALLATION INSTRUCTIONS
CHECK VEHICLE HEIGHT AND ADJUST
SPRING BARS IF NECESSARY
1. Vehicle should settle evenly, within 15mm.
Re-measure the front and rear bumper reference
points. If the front has settled much more than
the rear, increase the number of chain links
between the lift bracket and the spring bar. The
spring bars should be nearly horizontal when
correct height is achieved.
2. When even settling and correct spring bar
position have been achieved, mark the spring
bar chain at the hooked positiont, for future hook
up reference.
NOTE: Illustration 7, shows the correct and
incorrect hook-up position of the spring bars. To
allow movement when turning, there should be
at least 5 links between the lift bracket and the
spring bar. The number of links should be the
same on both bars. Adjust head tilt to
accomplish correct chain length.
TIGHTEN HEAD FASTENERS
Tighten both 3/4” x 4-1/2” hex bolts (9) to 260 ft.
lbs. Failure to tighten may result in fastener loss
or failure. Check the 5/8” Hex bolt (14) remains
tight after the first day of towing.
HOOK-UP OF SPRING BARS
CORRECT
AT LEAST 5 CHAIN LINKS
INCORRECT
LESS THAN 5 CHAIN LINKS
ILLUSTRATION 8.
BE SURE THAT CHAIN IS NOT TWISTED AND HOOK EXTENDS THOUGH LINK
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PAGE 6
MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM
DRIVING A TOW VEHICLE
TOWING TIPS & MAINTENANCE
TOWING TIPS
Good habits for normal driving need extra emphasis when towing a trailer. The additional weight of the trailer affects
acceleration and braking. Extra time should be allowed for passing, stopping and changing lanes. Signal well in advance
of a manoeuver to let other drivers know your intentions. Severe bumps and badly undulating roads can damage your
towing vehicle, hitch and trailer, and should be negotiated at a slow, steady speed. If any part of your towing system
"bottoms out" or if you suspect damage may have occurred in any other way, pull over and make a thorough inspection.
Correct any problems before resuming travel.
CHECK YOUR EQUIPMENT
Periodically check the condition of all your towing equipment and keep in top condition.
TRAILER LOADING
Proper trailer loading is very important. Heavy items should be placed close to the floor near the trailer axle centerline.
The load should be balanced side to side and firmly secured in the trailer to prevent shifting. Ball weight should be
approximately 10% of the gross trailer weight for most trailers. Too low a ball weight can cause a trailer to become
unstable and sway. Too high a ball weight can affect your trailers stability, steering and braking. If you are unsure of your
ball weight, Mister Hitches have a product called the Towsafe Ball Weight Scales (#MHBWS) which is a simple-to-use
and affordable way to measure you ball weight.
SWAY CONTROL
A sway control device can help minimise the effects of sudden manoeuvers, wind gusts and buffeting caused by passing
vehicles. Use of a Mister Hitches Friction Sway Control (#MHFSC) is recommended for trailers with a large surface area,
such as caravans. This head assembly can accomodate two sway control attachment balls (left & right).
TYRE INFLATION
Unless specified otherwise by the towing vehicle or trailer manufacturer, tyres should be inflated to their maximum recommended pressure.
TOWING VEHICLE AND TRAILER MANUFACTURERS RECOMMENDATIONS
Review the owners manual for your towing vehicle and trailer for specific recommendations, capacities and requirements.
SINGLE DRAWBAR TRAILERS
If your trailer has a single / straight drawbar, instead of the “A” frame drawbar shown on the illustrations in this instructions
manual, it will be necessary to use an adaptor for hook up of the weight distribution hitch lift brackets. Many boat trailers
have single drawbars.
TRAILER LIGHTS, TURN SIGNALS, ELECTRIC BRAKES
Always hook up all of the trailer lights, electric brakes and break-away switch connections, whenever the trailer is being
towed.
REMOVE HITCH WHEN NOT TOWING
Remove hitch from receiver on towing vehicle, when not towing a trailer, to prevent contamination of spring bar sockets,
reduce chances of striking hitch on driveway or other objects, and reduce the chance of parts being stolen.
MAINTENANCE
Keep the round ends of the spring bars and the sockets in the head assembly free from dirt and well lubricated.
Excessive wear in this area may indicate an overload or inadequate lubrication.
Keep the head assembly exterior clean, especially in the area of the spring bar retainer. Do not allow dirt or stones to
lodge in this area.
Keep hitch parts painted to prevent rust and maintain good appearance. Do not paint over labels.
Keep lift brackets clean and lubricated to ensure ease of operation.
AT THE BEGINNING OF EVERY TOWING DAY
Coat the round ends of the spring bars with a fibrous grease.
Clean ball and coupler socket and coat ball lightly with grease.
Check spring bar chains and U-bolts for wear and security. Replace before they become worn.
Check to see that all hitch bolts are properly tightened and that the locking pins in the lift brackets are securely in place.
Also, check that the hitch pin is in place and secure.
Check to see that all electrical hook-ups are in working order and that the safety chains are securely connected.
Check all trailer to towing vehicle connections for security and operation.
NOTE: Surge / over-ride brakes usually require a small amount of fore and aft movement for their actuating mechanism to
function. To avoid restricting movement, it may be necessary to increase the number of chain links between the lift
brackets and spring bars, by tilting the head down. Tighten the two 3/4" bolts to 260 ft. lbs. torque once head angle is set.
Those surge brake actuators not designed for use with a weight distributing hitch, may bind and not operate freely. Check
your surge brake operating instructions for any specific requirements regarding their use with weight distribution hitches.
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PAGE 7
MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM
WARNINGS & WARRANTY
WARNINGS
BALL HEIGHT: Loaded ball height should never be greater than the uncoupled ball height. Front wheel overload and loss of rear wheel
traction can result and can lead to unstable handling. It can reduce braking ability and create a tendency to “jack-knife” when turning or
braking at the same time. If the loaded ball height is greater than the uncoupled height, reduce take up on the spring bar chains and
remeasure and adjust until the proper height is obtained.
LIFT CHAINS: If the lift chain is angled fore or aft at the top within the lift bracket, it may catch on the bracket when turning. This could
damage the lift bracket or pry it open.
SHORT WHEEL BASE VEHICLES: Towing with a short wheel base vehicle may induce sway when towing.
SURGE/OVER-RIDE BRAKES: Some surge/over-ride brake systems are not compatible with weight distribution systems, please check
with the trailer manufacturer or the relevant operating instructions.
FRONT WHEEL DRIVE VEHICLES: Do not attempt to hook-up or tow with the rear tyres of the towing vehicle removed. Severe
structural damage to the towing vehicle, hitch and trailer may result. A towing vehicle/trailer combination cannot be controlled adequately
unless the towing vehicles rear wheels are carrying their share of the load.
OFF-ROAD USE: Never use a Weight Distribution System off-road. If you need to travel off-road, remove the WDS and replace with a
fixed tow ball mount.
Mister Hitches Weight Distribution Systems are only designed to perform on vehicles in good condition.
All replacement hardware must be of a type approved by this manufacturer.
Product specifications or the contents of this document are subject to change without notice.
DO NOT MODIFY ANY PART OF THE MISTER HITCHES WEIGHT DISTRIBUTION SYSTEM OR INSTALL
ON VEHICLES OTHER THAN THOSE SPECIFIED. THEY MUST ONLY BE USED TO TOW TRAILERS.
DO NOT OVERLOAD ANY PART OF YOUR TOWING SYSTEM.
NEVER EXCEED THE LOWEST RATING OF ANY PART OF YOUR TOWING SYSTEM.
WARRANTY
Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major
failure and for compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the
goods fail to be of acceptable quality and the failure does not amount to a major failure.
Intertrade Holdings Pty Ltd (“Mister Hitches”) provides the following warranty in relation to Mister Hitches Weight Distribution Systems (“Product”). The
benefits of this warranty are in addition to any rights and remedies imposed by Australian State and Federal legislation that cannot be excluded. Nothing
in this warranty is to be interpreted as excluding, restricting or modifying any State or Federal legislation applicable to the supply of goods and services
which cannot be so excluded, restricted or modified.
MISTER HITCHES LIMITED 25 YEAR WARRANTY
Subject to the exclusions and limitations below, Mister Hitches provides a 25 Year Warranty for Weight Distribution Systems from the first date of purchase at retail. The 25 Year
Warranty applies for so long as the product is owned by the original purchaser, or the recipient of the new product (by way of gift or promotion). The 25 Year Warranty does not
apply to a product that was purchased second hand.
If a defect appears in the product, Mister Hitches will, in its sole discretion, either:
1. Repair the product or the defective component of the product;
2. Replace the product or the defective component of the product; or
3. Issue a credit to the reseller who originally purchased the product from Mister Hitches.
Mister Hitches reserves the right to change the design, specifications or composition of the product without notice and without liability. Mister Hitches reserves the right to
replace defective products or components with products or components of similar quality, grade and composition, where an identical product or component is not available.
Goods presented for repair may be replaced by refurbished goods of the same type rather than being repaired. Refurbished parts may be used to repair the goods.
Warranty Claims
1. If a fault covered by this warranty occurs, the purchaser must return the product to the original place of purchase.
2. Any warranty claim must be accompanied by proof of original ownership (such as a receipt) and details of the alledged defect.
3. The cost of visiting the original place of purchase and/or returning the product to Mister Hitches is the responsibility of the purchaser. If a product is deemed defective,
it will be repaired or replaced when returned with transportation charges prepaid.
This 25 Year Warranty is limited to defects in the materials or workmanship of the product and does not cover accessories.
Exclusions
The 25 Year Warranty will not apply where:
a) The product has been on-sold or assigned by the original purchaser;
b) The product has been modified or repaired by someone other than Mister Hitches or a someone authorised by Mister Hitches;
c) Mister Hitches cannot establish any fault in the product after testing;
d) The product has been used other than for the purpose for which it was designed;
e) The product has been subject to abnormal conditions, including temperature, water, humidity, pressure, stress or similar;
f) The defect in the product has arisen due to abuse, misuse, neglect or accident;
g) The defect in the product has arisen due to the unlawful or unusual operation of the vehicle to which it is fitted;
h) The defect in the product has arisen due to the purchaser's failure to properly assemble, install, fit, maintain
or use the product in accordance with the specifications and instructions provided by Mister Hitches;
i) The defect in the product has arisen due to the overloading of the product beyond its specified or recommended capacities;
j) The defect is caused by normal wear and tear.
Limitations
Mister Hitches makes no express warranties or representations other than set out in this 25 Year Warranty.
The repair or replacement of the product, or a refund of the original purchase price of the product, is the absolute limit of Mister Hitches liability under this 25 Year Warranty.
NO REPRESENTATIVE, DEALER OR OTHER PERSON IS AUTHORISED TO ASSUME FOR MISTER HITCHES ANY ADDITIONAL, DIFFERENT OR OTHER LIABILITY IN
CONNECTION WITH THE SALE OF THIS MISTER HITCHES PRODUCT.
If you have a product problem covered under this warranty, please contact the reseller where you purchased this product from.
Secondly, you contact Mister Hitches;
Intertrade Holdings Pty Ltd, Unit 1 / 2 Tidal Way, Bibra Lake WA 6163
Tel: (08) 9418 7044 Fax: (08) 9418 7983 Email: [email protected]
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