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Diagnosis : Identifying Steering Damage
Collision repair often involves mechanical repair, too, and some body shops don't have the desire or expertise to deal with steering system damage. If you're ever called upon to repair front suspension damage, here is a rule of thumb for diagnosing a damaged or potentially damaged steering system: Diagnosis begins when the vehicle first arrives at the shop and doesn't end until after the owner picks it up. The reason for this extended diagnostic period lies in the fact that many of the steering systems' most important pieces -- for example, the gears or the rack -- are covered, sometimes making damage difficult to notice. In addition, some pieces do not show any signs of damage until after the vehicle is driven and normal road stresses are placed on them.
To diagnose steering damage you'll run two basic tests: a visual inspection and a road test. If you suspect the power steering units are damaged, you'll run a separate test on them with a steering system analyzer, which helps locate leaks. The visual inspection involves the interior steering pieces, the steering wheel and column, and the exterior parts.
There are a few things to keep in mind during the diagnosis. First, there's really no such thing as "typical" steering damage. Every accident is different, especially when it comes to how steering is affected. Second, steering system damage is more about angles than velocity. A direct hard hit at a particular angle can produce light or no damage, while a relatively light hit at another angle can cause severe damage. Third, severe suspension damage doesn't automatically imply heavily damaged steering components. This is also true in light hits.
When examining exterior parts, check the linkage and hoses for tears, hairline cracks and breakage. Be sure to use adequate lighting during the inspection. If the vehicle has a Pitman arm, shake it forcefully to check for any looseness. The same goes for other parts of the linkage and steering. Test suspect parts by pulling and pushing on them to determine if they've been knocked out of position or need to be tightened or replaced.
On rack-and-pinion systems, check for loose or damaged ball sockets at the tie rod ends and where the tie rods attach to the rack. Keep a sharp eye out for power steering fluid leaks. Small leaks often are hard to detect because the fluid builds up inside the bellows and doesn't show. Always wipe the gearbox and pump with a clean rag to help locate leaks.
After inspecting the underside of the car, thoroughly examine the interior. Look for cracks and bends to the steering wheel and column. If the airbag deployed, there's a good chance the steering wheel was damaged.
When the vehicle is roadworthy, take it for a sufficiently long test drive -- 30 minutes at the very least -- in different driving conditions and on different road surfaces. If possible, ask your technician or another qualified employee with a lengthy commute to test drive the vehicle by taking it home one night. Check for any "dead spots" in the steering -- areas where the steering seems ineffective. This is usually a sign of broken gear teeth. Also, listen for odd noises when the steering is turned and for loose pieces in the steering column.
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