How To Guides


Definition of Tire Terms


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  • Design Rim Width: "Design Rim Width" is the specific rim width assigned to each tire size designation to determine basic tire dimensions.
  • Section Width: "Section Width" is the maximum width of a new tire.
  • Overall Diameter: "Overall Diameter" is the diameter of an inflated tire at the most surface of the tread.
  • Maximum Load Capacity: "Maximum Load Capacity" is the maximum weight a tire is designed to carry under standard use conditions.
  • Load Identification: Load Range with a letter (A, B, C, etc.), Standard Load and Extra Load are used to identify a given size tire with its load and inflation limits when used in a specific type of service.
  • Ply Rating: is a term used to identify a given tire with its maximum recommended load when used in a specific type of service. It is an index of tire strength and does not necessarily represent the number of cord plies in the tire.
  • Static Load Radius: "Static Load Radius" is the dimension from the bottom of the tire to the center line of an axle when the tire is loaded at its rated capacity.
  • How The Tire Part Number System Works: The Part Numbers incorporate tire sizes and descriptions to allow you to easily determine the tires you need to order. For example, part numbers 7516BD and P215-75-R15BB can be interpreted as follows (see diagram)

How to Select Axles and Running Gear


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The following information is to help you make a selection of axles and running gear from our wide range of possible choices or call your branch and have one of our sales people assist you in choosing the right products.

  1. How to Determine the Gross Vehicle Weight (GVW)

    When building a trailer, the total Gross Vehicle Weight (GVW) must be determined in order to select the right axle or axles for the application. GVW includes the weight of the empty trailer and the weight of the intended cargo. (Example: 2,000 lb. empty trailer weight + 8,000 lbs. cargo = GVW of 10,000 lbs.)
  2. How Many Axles

    After determining the GVW; the number and capacity of the axles must be selected. For example, if you want 10,000 lb. GVW and want tandem axles, the minimum required capacity is 6,000 lb. per axle.
  3. Brakes

    First, determine if you want brakes on each axle. Most states require by law that at least one axle has brakes. Some states require that all axles have brakes. To determine how many brakes are necessary in a state, contact the local Department of Motor Vehicles. Second, determine what type of brake you prefer: Electric, Hydraulic Single-Serve, Hydraulic Free-Backing, Hydraulic Duo-Serve, Hydraulic Disc or Air "S" Cam Brakes
  4. Which Type of Spindles Are Going To Be Required

    Straight spindles are used mostly when the bed is over the tires or when low ground clearance is not required. Examples are flat beds, pull-type utility trailers, etc. Drop spindles are used when the lowest possible ground clearance is desired. Examples are Livestock and Horse Trailers, Car Haulers, Enclosed Cargo Van Trailers, etc.
  5. What Are the Spring Centers

    Spring Centers are the CL (centerline) measurement of the Spring Mounting Pads on the axle. Spring centers are usually matched to the approximate frame width of the trailer.
  6. Which Bolt Pattern

    The Bolt Pattern of the axles can vary depending on the capacity of the axle. The Bolt Pattern also determines what type tire and wheel can be used. If there is a specific tire and wheel you would like to use, please relay that information so we can help you to determine the proper bolt pattern and axle.
  7. What is the Length of the Axle

    The next step is to determine the length of the axle. Of the several ways and industry terms to describe this procedure, the most popular term is "Hub Face," which is the measurement from the base of the wheel stud to the base of the wheel stud on the opposite end of the axle. Another term frequently used is "Track". Track is the center of the tire to the center of the opposite tire. This measurement varies depending on what type of wheel is used, because each type of wheel (White Spoke, OEM, Custom) could have a different offset,changing the tire center.
  8. Which Type of Springs

    There are two basic types of springs to choose from: Double Eye or Slipper Springs. Double Eye Springs are used with the shackle-type suspensions. Slipper Springs are the heavy-duty springs used with slipper-type suspensions. Complete sets of springs and u-bolt kits can be ordered with axles.
  9. Which Hanger Kit

    There are several Hanger Kits to choose from - single, tandem or triple for both double eye and slipper springs. Hanger Kits consist of Spring Hangers that attach to the frame, Equalizers (tandem or triple Hanger Kits), Shackle Straps (if double eye springs) and all the necessary hardware.

How to Order Tubular Axle Assemblies


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Our part numbers for Axles are assigned in accordance to the capacity, bolt pattern, type of brakes (if any) and type of spindle used. When ordering axles, the following information should be helpful to you.

EX: 20545I-ST-EZ2,000 lb., 5 on 4 1/2 Idler Straight with E-Z Lube

20/545/I/ST/EZ

20:
The first group of digits represent the capacity (20=2,000 lb. capacity)
545:
The next group represents the number of studs and the bolt pattern of the studs
(545=5 on 4 1/2 , 655=6 on 5 1/2 , 865=8 on 6 1/2 , etc.)
I:
This tells you which type of brakes are used, if any.
(I=Idler, E=Electric, H=Hydraulic, HFB=Hydraulic F=Free-Backing, A=Air)
ST:
This tells you which type of spindles are used (ST= straight, 4D=4 Drop)
EZ:
Any other options ( EZ=E-Z Lube Spindle, SPR=Springs Mounted)

How to Select Torflex Axles


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  1. How to Determine the Gross Vehicle Weight (GVW)

    When building a trailer, the total Gross Vehicle Weight (GVW) must be determined in order to select the right axle or axles for the application. GVW includes the weight of the empty trailer and the weight of the intended cargo. (Example: 2,000 lb. empty trailer weight + 8,000 lbs. cargo = GVW of 10,000 .)
  2. How Many Axles

    After determining the GVW; the number and capacity of the axles must be selected. For example, if you want 10,000 lb. GVW and want tandem axles, the minimum required capacity is 6,000 lb. per axle.
  3. Brakes

    First, determine if you want brakes on each axle. Most states require by law that at least one axle has brakes. Many states require that all axles have brakes. To determine how many brakes are necessary in a province, contact the local Department of Motor Vehicles. Second, determine what type of brake you prefer. Choose from Electric, Hydraulic Single-Serve or Hydraulic Duo-Serve.
  4. What is the Length of the Axle

    Of the several ways and industry terms to describe this procedure, the most popular term is "Hub Face" which is the measurement from the base of the wheel stud to the base of the wheel stud on the opposite end of the axle
  5. Which Bolt Pattern

    The Bolt Pattern of the axles can vary depending on the capacity of the axle. The Bolt Pattern also determines what type tire and wheel can be used. If there is a specific tire and wheel you would like to use, please relay that information so we can help you to determine the proper bolt pattern and axle.
  6. What is the Outside Frame Dimension

    Since the mounting brackets of the Torflex axles mount directly to the frame of your trailer, it is necessary to know the outside frame measurement in order to install them on the axle correctly.
  7. How to Determine the Trailing Arm Starting Angle

    The starting angle is the position of the spindle in reference to the trailer frame. In order to make it simpler to select the starting angle for your Torflex axle, consult the tables which appear at the bottom of each Torflex axle page.

How to Read Torflex Articulation Dimensions


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Note: Dimensions shown here are for example only: Refer to specific Torflex Axle Page for correct dimensions.

  1. How high do I set the fenders

    Look at the 0 drawing: The 2.2 is distance from center of spindle to top of bracket. The .1 is how far arm moves bracket for 'Full Load'.

    2.2 To top bracket
    +.1From top bracket to 'Full Load'
    2.3 Travel from 'No Load' to 'Full Load'

    Fenders should be located 5.7 above tires when 'No Load' (2.3 + 3.00 DEX REQ).

  2. What is 'Shock Load'

    'Shock Load' 1.6 is how far arm travels above the top of bracket. The distance the arm moves from 'Full Load' to 'Shock Load' is the difference of 1.5.

    1.6 Distance arm moves from 'Full Load' to 'Shock Load'
    -.1Full Load Dimension
    1.5 Travel from 'Full Load' to 'Shock Load'
  3. What do the + marks on the curved broken line represent

    This line tells us how far forward the tire moves at each of the load points.

    Using the 0 drawing again: Notice the 6.0 distance from center of spindle to center of inner bar. When the arm travels up to 'Full Load', the tire is moved forward .4 . At 'Shock Load', the tire has moved forward 1.4 .

  4. When trailing arm starts at 22.5¦ or 45¦ down, the calculations are subtractions rather than addition.

    Look at 22.5 down drawing.

    'No Load' is 4.5 from top of bracket
    'Full Load' is 2.3 from top of bracket
    2.2 Travel from No Load to Full Load'

'Shock Load' is .4 above top of bracket, so the travel from 'Full Load' 2.3 to 'Shock Load' .4 is 2.7 .

How to Order Torflex Axles


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Our part number system for Torflex Axles is very similar to that of the tubular axles. Please place your order according to the description based on the following information/example:

EX:12TF70-865E-EZ#12 Torflex,7,000 lb., 8 Bolt, 6.5" Bolt Pattern, Electric Brake, E-Z Lube

12TF :
Model of Torflex Axle (#8, #9, #10, #11, #12, or #13)
70 :
Capacity of Torflex Axle (70 = 7,000 lb. capacity)
865 :
8 Bolt, 6.5" Bolt Pattern
E :
Type of Brake, if any (I = Idler, E = Electric, H = Single Serve Hydraulic, HY = Duo-Serve Hydraulic)
EZ:
Type of Lube (EZ = E-Z Lube, OIL = Oil)

It is also necessary that you give us the outside dimension of your frame and the starting angle of the trailing arm.

How to Determine Correct Axle Position


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1.Weigh the trailer (under wheels) "Wheel Weight"
2.Obtain "Tongue Weight" (Actual)
3.Measure distance from tongue to axle, or to
center between Dual Axle Set (D)
4.Determine Total Weight
Total Weight=Tongue Weight + Wheel Weight
If tongue weight is greater than 10% of
Total Weight, decrease distance D by X where

X=(Tongue Weight - 10% Total)Times D
Total Weight
If tongue weight is less than 10% of
Total Weight, increase distance D by X where

X=( 10% Total - Tongue Weight )Times D
Total Weight
Example #1 - Tongue greater than 10% of Total Weight
Example #2 - Tongue less than 10% of Total Weight
Tongue Weight=
Wheel Weight=
D=
Total Weight=
% Tongue Weight=

X=
1025#
7200#
264
8225#
1025=0.1246 or 12.5%
8225
1025 - 822.5 Times 264=6.499
8225
Tongue Weight=
Wheel Weight=
D=
Total Weight=
% Tongue Weight=

X=
300#
8200#
264"
8500#
300=0.035 or 3.5%
8500
850 - 300 Times 264=17
8500

Move the Axle(s) toward theTongueof the trailer approximately 6.5"
New D=264 - 6.5"=257.5"
Move the Axle(s) toward theRear of the trailer approximately 17"
New D=D + 17"=264 + 7=281"

How to Order Replacement Hubs or Hub and Drums


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To order the correct replacement hub or hub and drum, the following steps can be used to simplify the ordering process:

  1. Determine the Bolt Pattern of the Hub.
  2. Determine the Inner and Outer Bearing Numbers. Note whether the bearings use grease or oil bath lubrication.
  3. Measure the old hub seal to insure that the I.D. and O.D. dimensions will be the same.
  4. Verify the Stud Diameter.
  5. If the axle is a brake axle, measure the diameter and width of the brake to determine brake size.
  6. Look for any casting numbers on front or rear of hub or hub and drum.
  7. On heavier axles, such as the Dexter 8,000 lb. or 9,000 lb. axles, you need to determine the hub pilot diameter. This can be accomplished by measuring the center hole of your wheel.
  8. On 8,000 lb and larger axles determine if it is equipped with ABS, and requires a drum / rotor with ABS exciter ring installed.

Once you have the above information, you are ready to locate your replacement hub or hub and drum. Locate the bolt pattern desired, then find the table that lists our inner and outer bearing numbers.

Verify:

  • Inner/Outer Bearing Numbers
  • Type of Bearing Lubrication
  • Stud Size
  • Seal Size
  • Drum Size

Confirm brake size and/or hub pilot diameter (if applicable). Complete assemblies contain the hub or hub and drum, inner and outer bearings, seal, grease cap or oil cap and all necessary wheel nuts.

How to Select Electric Brakes and Brake Parts


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Few Things To Keep In Mind:

  1. To determine the right or left side brake assembly, position the brake with themagnet at the bottom.On electric brakes, the actuating arm will always curve from the pivot pin to the magnet, toward the left for left hand brakes and toward the right for right hand brakes. (See the illustration.)
  2. When ordering your brake assembly or brake replacement part, alwaysuse both the part number and the reference number. Both are necessary to insure prompt and correct filling of your order.
  3. Sometimes the easiest, most economical way to repair a brake is to replace the complete assembly. By removing wires and a few nuts and bolts, you haveall new parts,saving time, trouble and expense.
  4. Whether you choose to replace the entire brake assembly, only individual parts in need of repair, or need new brakes to build a trailer--We have what you needto do the job right! We are just a telephone call away.

Selecting Electric Brake Parts:

  1. Determine the size of your brake.
    1. A. Measure the diameter of the mounted brake shoe.
    2. B. Measure the width of the lining Actuating Arm
  2. Determine the manufacturer of your brake.
    1. A. Select the brake you have by looking at the key identification points shown in the drawing.
    2. B. Check the electric brake chart for your brake and the part you need. Further identification may be made by referring to the exploded drawings and magnet photos of each brake.
  3. Select the part you need. Though many parts are shown, we carry only the replacement parts numbered. The words "Parts Only" indicate that complete brake assemblies are not available.

Using The Electric Brake Chart:

  1. Find the picture that matches the assembly or the part you need.
  2. The part and reference numbers are just below the picture of your assembly or part. Part and reference numbers are placed beside the photo of individual replacement parts. Use them to order what you need.
  3. Double check your part against its listing in the pages Adjuster Spring which show the exploded drawings, assembly and magnet photographs.
  4. Call or fax your order to our location nearest you.

Reasons Why Brake Hardware Should Be Replaced:

  1. Worn, weak return springs will cause the brake linings to drag against the drum and cause premature brake failure.
  2. Hold-down springs will lose their tension and allow the brake shoes to wobble or ride up against the face of the brake drum, causing premature lining failure.
  3. A frozen adjusting screw will not allow shoes to be adjusted properly.
  4. Rubber dust plugs will crack with age and allow dirt to contaminate linings. (Not shown.)
  5. A stretched self-adjusting cable prevents the self-adjusting lever from properly aligning the shoes. (Not shown or illustrated.)

Electric Brake Trouble Shooting Guide


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PROBLEM
CAUSES
REMEDIES
NO BRAKES
OPEN CIRCUITS
FIND AND CORRECT
SEVERE UNDERADJUSTMENT ADJUST BRAKES
FAULTY CONTROLLER TEST AND CORRECT
SHORT CIRCUITS FIND AND CORRECT
WEAK BRAKES
GREASE/OIL ON MAGNETS/LININGS
CLEAN OR REPLACE
CORRODED CONNECTIONS CLEAN/CORRECT CAUSE
WORN LININGS OR MAGNETS REPLACE
SCORED/GROOVED BRAKE DRUMS MACHINE OR REPLACE
IMPROPER SYNCHRONIZATION CORRECT
UNDER ADJUSTMENT ADJUST BRAKES
BLAZED LININGS REBURNISH OR REPLACE
OVERLOADED TRAILER CORRECT
LOCKING BRAKES
UNDER ADJUSTMENT
ADJUST
IMPROPER SYNCHRONIZATION CORRECT
FAULTY CONTROLLER TEST AND CORRECT
LOOSE, BROKEN BRAKE PARTS REPLACE COMPONENTS
OUT OF ROUND BRAKE DRUMS MACHINE OR REPLACE
INSUFFICIENT WHEEL LOAD ADJUST SYSTEM RESISTOR
INTERMITTENT BRAKES
FAULTY CONTROLLER
TEST AND CORRECT
BROKEN WIRES REPAIR OR REPLACE
LOOSE CONNECTIONS FIND AND REPAIR
BRAKES PULL TO ONE SIDE
INCORRECT ADJUSTMENT
ADJUST
GREASE/OIL ON LININGS/MAGNET CLEAN OR REPLACE
BROKEN WIRES FIND AND REPAIR
BAD CONNECTIONS FIND AND REPAIR
HARSH BRAKES
UNDER ADJUSTMENT
ADJUST
IMPROPER SYNCHRONIZATION CORRECT
IMPROPER CONTROLLER CHANGE
FAULTY CONTROLLER TEST AND CORRECT
NOISY BRAKES
UNDER ADJUSTMENT
ADJUST BRAKES
LACK OF LUBRICATION LUBRICATE
BROKEN BRAKE PARTS REPLACE COMPONENT
INCORRECT BRAKE PARTS REPLACE
SURGING BRAKES GREASE/OIL ON LININGS/MAGNET
CLEAN OR REPLACE
OUT OF ROUND BRAKE DRUMS MACHINE OR REPLACE
FAULTY CONTROLLER TEST AND CORRECT
DRAGGING BRAKES
OVER ADJUSTMENT
READJUST
OUT OF ROUND BRAKE DRUMS MACHINE OR REPLACE
INCORRECT BRAKE PARTS REPLACE
BROKEN BRAKE PARTS REPLACE
FAULTY BREAKAWAY SWITCH REPAIR OR REPLACE
LOOSE WHEELBEARING ADJ. ADJUST
BENT SPINDLE REPLACE AXLE

How to Select Hydraulic Brakes and Brake Parts


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THE SINGLE-SERVO / DUO-SERVO DIFFERENCE:

1.SINGLE-SERVO: Single plunger coming from the wheel cylinder, most commonly used with Surge Brake applications.
2. DUO-SERVO:Two plungers coming from the wheel cylinder, stops vehicle in both forward and reverse motion.

SELECTING HYDRAULIC BRAKE PARTS:

1. Determine the size of your brake.
a. Measure the diameter of the mounted brake shoe.
b. Measure the width of the lining.
2. Determine the manufacturer of your brake.
a. Is the manufacturer's name on the backing plate
b. Compare to complete Brake Assembly or to exploded drawings in this catalog.
3. Select each part you need. The exploded drawings of each brake are to assist you in selecting the parts you need. Though all parts may be shown, we carry replacement parts only for those that are numbered. Parts labeled "Parts Only" indicate that complete brake assemblies are not available.

USING THE HYDRAULIC BRAKE CHART:

1. Find the picture that matches the assembly or the part you need.
2. The part and reference numbers are just below the picture of your assembly or part. Part numbers are placed beside the photo of individual replacement parts. Use the part number to order what you need.
3.Double check your part against its listing in the pages which show the exploded drawings.
4. Call or fax your order to the location nearest you.

REASONS WHY BRAKE HARDWARE SHOULD BE REPLACED:

A. Worn, weak return springs will cause the brake linings to drag against the drum and cause premature brake failure.
B. Hold down springs will lose their tension and allow the brake shoes to wobble or ride Duo-Servo Cylinder up against the face of the brake drum, causing premature lining failure.
C. A frozen adjusting screw will not allow shoes to be adjusted properly.
D. Rubber dust plugs will crack with age and allow dirt to contaminate linings. (not shown or illustrated)
E. A stretched self-adjusting cable or worn lever prevents the self-adjusting lever from properly aligning the shoes. (Not shown or illustrated)

Wheel Selection How-To's


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A great deal of thought and consideration should be given when selecting trailer wheels.
Important choices must be made from the various wheels on the market. When combining wheels, tires, hubs and axles, the load carrying capacity is limited to whichever component has the lowest capacity. Load capacities relate specifically to generally accepted standard axle applications for conventional trailers used In normal highway service, loaded equally side-to-side. Unusual axle configurations, unequal fore and aft loading, or overload conditions can cause premature failure of wheels, tires and/or other parts.

How To Determine Bolt Pattern:


Match wheels to hubs by the number of bolts and bolt circle. To determine the bolt circle on wheels with an even number of bolt holes, measure center-to-center on bolt holes directly across from each other on the diameter (Example: 8 on 6 1/2 would mean 8 bolt holes with 6 1/2" center-to-center diameter). On odd number bolt wheels, measure any bolt hole center to the point halfway between bolt holes on the diameter (Example: 5 on 4 1/2 would mean 5 bolt holes with 4 1/2" measure to a point halfway between the opposite bolts).

How to Determine Wheel Offset:


Offset is the distance between the mounting face of the disc and rim centerline.
Inset: Refers to the distance when the mounting face is outboard of the rim centerline.
Outset: Refers to the distance when the mounting face is inboard of the rim centerline.

Selecting a Ball Mount with the Correct Rise or Drop


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Replacement Axle Spec Sheet


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Measuring for Replacement Torflex Axles

Determine where the center of the spindle is in relationship to the bottom of the main frame to help determine closest articulation angle.

Measuring for Replacement Spring Axles

How to Determine Which 5 Bold Pattern You Have


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HUB A B C
5 BOLT 4.50" B.C. 2.645" 4.280"
5 BOLT 4.75" B.C. 2.792" 4.518"
5 BOLT 5.00" B.C. 2.939" 4.755"
5 BOLT 5.50" B.C. 3.233" 5.231"

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