Keeping up down under

| November 03, 2005

Alignment pays for itself in increased tire life and reduced fuel consumption many times over. It only takes a good technician a short time to align axles unless there are mechanical problems like bad wheel bearings or bent suspension components that need to be repaired. If misalignment is severe enough, it can ruin a set of tires in a single trip!

On the Hutch spring ride, alignment is adjustable via an adjustable radius rod on one side. The technician just loosens the lockbolts at either end and then rotates the center section of the rod to move that side of the axle forward or backward as necessary.

On the Hendrickson Intraax, there is an egg-shaped eccentric on either side. The technician just loosens the lockbolt and then uses a socket bar in the square hole to rotate the eccentric and move that end of the axle in the right direction. Adjustments are provided on both sides so that the distance between axles can be adjusted as well as the angle of each axle in relation to the trailer frame. Both axles must be adjusted on both sides during an alignment operation.

The landing gear
Landing gear uses a high speed gear ratio to raise and lower legs to the ground when the trailer is hooked up, and a low gear to raise and lower the trailer once the legs are supporting it. The No. 1 abuse of this system is dropping the trailer when the legs are not yet resting solidly on the ground.

When lowering the legs, once they touch the ground, the low gear should be engaged and the legs extended another inch or two to ensure they are adequately supporting the trailer.

The number one maintenance issue is greasing. There are typically grease points on the gearbox, as well as on the body, in order to cover the entire mechanism. The leg itself, where it slides up and down inside the body of the unit, should also be greased to prevent abrasive wear.

No. 2 issue is bolt torque. Torque all bolts to specifications periodically. Also, inspect all brackets carefully and replace if cracked.

You can tell when the landing gear’s internal gearing has worn and the mechanism needs replacement. You’ll feel the gears strip as you turn the crank instead of getting a steady lowering or raising of the legs.

Wheel bearing lubrication
Many wheels use oil in their bearings. With oil-lubed bearings, it’s easy to check the level and replenish. But you have to keep after them because even a small defect in a seal means the oil will quickly leak out. So keep your eyes pealed for any sign of oil leakage and also check the fill level frequently. Leakage means the hub must be disassembled and the oil seals replaced, a precision operation.

Any sign of oil leakage onto the brakes puts the trailer out of service.

Lube level can be easily seen through the sight glass. You can add fluid by either removing the small filler plug in the top of the housing (after rolling the wheel until it’s at the top), or by removing the red plug in the center. You can see the rings that indicate that the unit is full or that level has dropped to the point where it is essential to add oil. Check your owner’s manual for the correct viscosity and other specifications.

Total capacity is about 1 1/4 pints. After adding oil, spin the wheel a few revolutions and then recheck the level to make sure it is still correct. Add more oil, if necessary.

Many wheel bearings use grease rather than oil because, if a seal should fail, leakage will occur only very slowly. The downside of grease is that bearing must be disassembled and repacked carefully periodically and whenever the bearing and seals are serviced.

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