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PowerLine Trailers™ Resource Center

Wheel Torque Requirements

Wheel Size Torque Sequence
1st Stage 2nd Stage 3rd Stage
12" 20-25 35-40 50-75
13" 20-25 35-40 50-75
14" 20-25 50-60 90-120
15" 20-25 50-60 90-120
16" 20-25 50-60 90-120
16.5" x 6.75" 20-25 50-60 90-120
16.5" x 9.75" 55-60 120-125 175-225
14.5" Demount. Tighten sequentially to 85-95
17.5" Hub Pilot
Clamp Ring & Cone Nuts
50-60 100-120 190-210
17.5" Hub Pilot
⅝" Flange Nuts
50-60 90-200 275-325
Torque Bolt Diagram

Trailer Maintenance Schedule

Item Function Required Weekly 3 Months or
3,000 Miles
6 Months or
6,000 Miles
12 Months or
12,000 Miles
Brakes Test that they are operational. At Every Use
Breakaway System Check battery charge and switch operation. At Every Use
Tire Inflation Pressure Inflate tires to mfg's. specifications. X
Brake Adjustment Adjust to proper operating clearance. X
Wheel Nuts and Bolts Tighten to specified torque values. X
Tire Condition Inspect for cuts, wear, bulging, etc. X
Brake Magnets Inspect for wear and current draw. X
Brake Controller Check for correct amperage & modulation. X
Suspension Parts Inspect for bending, loose fasteners, wear. X
Wheels Inspect for cracks, dents or distortion. X
Brake Linings Inspect for wear or contamination. X
Trailer Brake Wiring Inspect wiring for bare spots, fray, etc. X
Hub/Drum Inspect for abnormal wear or scoring. X
Wheel Bearings & Cups Inspect for corrosion or wear. Clean & repack. X
Seals Inspect for leakage. Replace if removed. X
Springs Inspect for wear, loss of arch. X
Hangers Inspect welds. X

Brake Troubleshooting


Causes Remedies
Open Circuits Find & Correct
Severe Underadjustment Adjust Brakes
Faulty Controller Test & Correct
Short Circuits Find & Correct
Causes Remedies
Grease or Oil on Magnets or Linings Clean or Replace
Corroded Connections Clean & Correct Cause of Corrosion
Worn Linings or Magnets Replace
Scored or Grooved Brake Drums Machine or Replace
Improper Synchronization Correct
Underadjustment Adjust Brakes
Glazed Linings Reburnish or Replace
Overloaded Trailer Correct
Causes Remedies
Underadjustment Adjust
Improper Synchronization Correct
Faulty Controller Test & Correct
Loose, Bent or Broken Brake Components Replace Components
Out-of-Round Brake Drums Machine or Replace
Insufficient Wheel Load Adjust System Resistor and Synchronize
Causes Remedies
Faulty Controller Test & Correct
Broken Wires Repair or Replace
Loose Connections Find & Repair
Faulty Ground Find & Repair
Causes Remedies
Wrong Magnet Lead Wire Color Correct
Incorrect Adjustment Adjust
Grease or Oil on Linings or Magnets Clean or Replace
Broken Wires Find & Repair
Bad Connections Find & Repair
Causes Remedies
Underadjustment Adjust
Improper Syncronization Correct
Improper Controller Change
Faulty Controller Test & Correct
Causes Remedies
Underadjustment Adjust
Lack of Lubrication Lubricate
Broken Brake Components Replace Component
Incorrect Brake Components Correct
Causes Remedies
Grease or Oil on Linings or Magnet Clean or Replace
Out-of-Round or Cracked Brake Drums Machine or Replace
Faulty Controller Test & Correct
Causes Remedies
Overadjustment Readjust
Out-of-Round or Cracked Brake Drums Machine or Replace
Incorrect Brake Components Replace
Loose, Bent or Broken Brake Components Replace
Faulty Breakaway Switch Repair or Replace
Loose Wheel Bearing Adjustment Adjust
Bent Spindle Replace Axle

How To rewire a Trailer Plug

Our trailers are wired using the most common color coding for the trailer industry. The chart below gives the trailer wire color, its electrical function and where to connect on the proper plug or connector. Before starting, verify all wiring with a test light.

Trailer Wire Color Electrical Function Flat 4-Way Plug 6-Way Plug 7-Pole RV Connector
White Wire Trailer Ground White Wire GD 1 White
Brown Wire Tail & Marker Lights Brown Wire TM 3 Green
Yellow Wire Left Turn Yellow Wire LT 5 Red
Green Wire Right turn Green Wire Rt 6 Brown
Blue Wire Electric Brakes S* 2 Blue
Black Wire Accessory / Battery W A* 4 Black
Red Wire Auxiliary 7 Yellow
* Some manufactures use A for brakes and S for Accessory/Battery.
Flat 4-way plug diagram
6-way plug diagram
7 pole RV connector diagram

Tire Wear Diagnostic Chart

Wear Pattern Cause Action
Center Wear Center Wear Over Inflation Adjust pressure to particular load per tire catalog
Edge Wear Edge Wear Under Inflation Adjust pressure to particular load per tire catalog
Side Wear Side Wear Loss of camber or overloading Make sure load doesn't exceed axle rating. Align at alignment shop.
Toe Wear Toe Wear Incorrect toe-in Align at alignment shop.
Cupping Cupping Out-of-balance Check bearing adjustment and balance tires.
Flat Spots Flat Spots Wheel lockup & tire skidding Avoid sudden stops when possible and adjust brakes.

How To Determine Trailer Bolt Patterns

Trailer bolt patterns are called out by two numbers. An example would be 6 on 5-1/2. The first number represences the number of holes on the wheel or studs on the hub / drum. In this case 6 holes or studs. The second number represences the centerline circle the holes or the studs are on. In this case 5-1/2 inch diameter circle.

Wheels with an even number of holes, measure center-to-center on the holes or studs directly across each other. We have made wheels with an odd number of holes easy to determine. Simply measure center-to-center on the holes or studs, skipping one between the measurements. See the diagrams below.

8 on 6-1/2 Bolt Pattern

8 on 6-1/2

6 on 5-1/2 Bolt Pattern

6 on 5-1/2

5 on 5 Bolt Pattern

5 on 5

5 on 4-1/2 Bolt Pattern

5 on 4-1/2

4 on 4 Bolt Pattern

4 on 4

PowerLube Axle™

The PowerLube Axle™ is a hole drilled through the center of the axle that meets a cross drilled hole located between the rear bearing and the back seal. The end of the hole is then threaded for a grease zerk. This allows for a fast and easy wheel bearing grease repack. Below are instructions and a diagram.

First, romove the rubber plug. Second, fully insert a standard grease gun onto the grease fitting. Third, pump grease into fitting while rotating the hub or drum. The old grease will begin to flow back out of the cap around the grease gun nozzle. Finally, when new clean grease appears, remove the gun, wipe off all old and excess grease and replace the rubber plug.

PowerLube Axel