Front End Inspection
Nothing's more important for safety than steering. Check components closely.
Motorists have been badly injured or killed by rolling wheels, and trucking companies ordered to pay millions in the resulting court Fix such things now.
ED THOMAS
CONTRIBUTING EDITOR
Here's an absolute statement: Nothing on any motor vehicle is more important to safety that its steering system. Bad brakes and tires can cause a truck to go when it should stop, or stop when it should go, and hit something in the process. But bad steering can send a truck out of control in just a few feet, and put it out of service right here, right now.
Problems with the front end's various steering parts that should be looked for anytime anybody with any mechanical knowledge is under the truck doing anything. A technician should eyeball linkage along the front axle and steering gear, including the pieces ahead of the firewall. And the driver should look at these things as part of the pre-trip inspection.
ATA's Technology & Maintenance Council's Recommended Maintenance Practices manual includes a "pre-alignment" checklist that can double as a safety check. Here are some of the list's items:
1. Check all tire pressures and air up if necessary.
2. Steering components
• Draglink, and tie rod and ends — for damage, tightness and wear, and adequate lube;
• Pitman arm — connecting nut should be secure, properly torqued and locked.
3. Steering sector.
• Tightness or looseness in the steering wheel, and gear play;
• Gear box-to-frame mounting bolts must be secure and properly torqued.
4. Steering shaft.
• Damage and wear in moving parts
• Proper lube in the driveline, U-joints and portions of the linkage.
5. Steering knuckle.
• Worn or damaged kingpin seals, bushings and bearings.
• Proper lubing where needed.
6. Maximum steer angle — check the stopscrew for proper setting so each wheel can turn as tightly as possible without contacting any chassis component.
7. Brake drum centering — With hub-piloted wheels (now the industry standard), drums can be adjusted by loosening and retorquing the wheel nuts. Do this after jacking up each wheel-end, and, with brakes released and other wheels chocked, spinning the wheel and feeling for incomplete shoe contact (the shoe touches at one point of the rotation, then loosens as the spin continues). If this is felt, loosen the nuts and apply the brake to straighten the drum, then retighten and torque the drum.
8. Wheel bearing end play and condition — A whole subject unto itself. See accompanying story for things to watch for during a walk-around inspection.
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Early Signs and Symptoms of Wheel-End Problems
