TARA Panel Discusses Chassis Damage

THREE members of the Truck-frame & Axle Repair Association (TARA) discussed different types of damage that may not be apparent on vehicles involved in an accident.

The presenters were long-time TARA members and board members: Ken Dias of Dias Spring Service Inc in Erie, Pennsylvania; David Medley of Medley's Auto & Truck in Louisville, Kentucky; and Jim Roark of Akron Wheel & Frame Inc in Akron, Ohio.

Dias said that he begins his damage inspection by walking around the vehicle. "Take an overview of the damage you see initially," Dias said. "Then start writing the damage estimate from the front bumper to the rear of the truck."

Dias described an estimate he wrote recently on a tractor damaged in a rollover. In the accident, the hood was ripped from the vehicle and set back on the tractor by the tow truck driver.

The vehicle was inspected by Dias in a tow yard after business hours; and he could not move the hood by himself to inspect the engine compartment. Neither could the insurance adjuster who wrote his estimate after inspecting the vehicle.

"We had no clue to any damage underneath the hood," Dias said. "Often, the vehicle must be in the shop for a thorough damage inspection."

Obvious Truck Damage The obvious damage on the tractor included a bent exhaust stack from the impact with the cab, a shock absorber on the back of the cab that was snapped in half, a broken cab air-ride, and a bent rear cab mounts.

Scrapped wheel studs on a rolled-over tractor must be replaced, Dias said. Anytime there is collision damage to the front of a tractor, a tire with a mark should be dismounted and the interior inspected for damage.

On another tractor he inspected recently, a power-steering hose was rubbing on the universal joint of the steering shaft, Dias said. After moving the hose, Dias could see it was abraded almost through.

"To protect your shop, make a thorough inspection," Dias said. "The customer expects the truck back in as good or better condition than it was before the wreck. Make sure your business isn't held accountable for subsequent repairs."

Other items to inspect in a front-end collision are the steering-arm, drag-link, brake cams, slack adjusters, missing pins, front motor mounts, alternator brackets, belts, pulleys, fan blades, radiators, and fan shrouds. In some front-end collisions, sector shafts in steering boxes can become bent, as can U-bolts on front axles. Measuring Frame Damage

Medley spoke about making field inspections of frame rails on damaged tractors. It is best to make a correct estimate in the field, before a vehicle with possibly damaged frame rails reaches the shop.

First determine what equipment must be removed to repair damaged frame rails, Medley said. Tools are available to accurately measure in the field frame damage such as twist. Besides frame rails, other components on a frame can become damaged.

"A lot more can be damaged on a frame than just one rail," Medley said. "When it comes to frame damage, we have to look at the whole picture. When there is extreme twist in a frame, you better look at the crossmembers."

During a damage inspection, the crossmembers may be the most important part of the frame structure. This is especially true when estimating the time it will take to repair a frame having damaged crossmembers.

On the rear section of a frame Medley inspected recently, the rear crossmember was buckled in addition to damage to both frame rails. Initially more attention is paid to the main damaged area while more obscure other damages can be missed.

Medley told about another tractor. The frame rails had sidesway and several crossmembers were damaged in a side-impact accident. Simple tools such as a four-foot levels with a straight edge and a carpenter's framing square can be used to help diagnose frame damage.

Determining Diamond, Sidesway Using a framing square on the front, center, and rear of the frame will show if the frame has a diamond or sidesway, Medley said. Determining the precise amount of diamond or sidesway is difficult outside of the shop, "but using a framing square is a good way to show a supervisor or an insurance adjuster if a frame has diamond or sidesway," Medley said.

Measuring the outside of the frame with a straightedge can help determine the amount of sidesway, he said. Everyone involved in an accident claim wants to know how much sidesway is in a damaged truck frame. Eventually, the insurance adjuster and the repair shop need to agree on the amount of sidesway.

It is becoming increasingly difficult to inspect truck frames because of aerodynamic cab fairings and skirts, Medley said. A Torpedo level is small and attaches magnetically, making it a good tool to inspect hard-to-reach frame rails.

"You can attach it to a frame rail behind a fuel tank and determine if there is any damage without removing the fuel tank," he said.

When inspecting a frame, check to see that the vehicle is sitting on level ground, Medley said. By placing a four-foot level on the ground near the front axle, it is easy to determine if the frame rails are twisted.

"If the ground is uneven, that needs to be taken into consideration when taking photographs or measuring the vehicle," Medley said.

Inspecting Frame Rails Sidesway on frame rails can be measured easily just ahead of the fifthwheel, he said. This will show up if sidesway is drastic. However, a build-up of grease on the frame rails near the fifthwheel can interfere with sighting a frame rail tosee if it is straight.

Inspect the frame rail underneath the fifthwheel and use the level, Medley said. Trucks often cannot be moved for an inspection. If the truck was involved in a rollover accident, use a level to check the fifthwheel plate.

"A four-foot level is easy to carry in a car or truck," Medley said. "Sidesway can be discovered easily by using three levels placed at the front, middle, and rear of the frame rails."

Checking the axle tracking of a truck also will reveal sidesway and diamond, Medley said. Climbing on top of the frame rails and looking down at the axle housing is another way to determine if the tracking is off and the axle is damaged.

During a walkaround inspection of a damaged tractor with only 50,000 miles on the odometer, Roark noticed different distances between the front fender and tire on each side of the vehicle, he said. In addition, the left wheel had impact damage, the front bumper had a small dent, and the right cab step was bent upward.

"No other sheet metal damage was visible," Roark said. "The other damage must have been underneath. The truck must have gone over a guard rail."

Finding Unseen Damage Roark noticed that part of the front axle on a new truck appeared to be rusted and the U-bolts were deformed. This was from stress damage caused by an impact.

After removing the front bumper, it was apparent that one frame rail was bowed and pulled down in the front, Roark said. An impact with a spring hanger bowed the frame rail, and the stabilizer bar and steering controls were damaged.

On another tractor damaged in a front-end collision, a sector shaft in a steering box was twisted, Roark said. Drivers usually notice if the steering is off track. Instead of being straight, the splines on the sector shaft will have a dip or twist caused by a collision.

"In most accidents, unless the impact is very severe, the shaft will not separate from the steering box but it will twist," Roark said.

Check the spring-shackle bushings and see that the springs attach correctly to the frame rail, Roark said. Make sure each spring has the same number of leaves with the same thickness. Often a commercial truck will have extra leaves in one rear spring because a crane or other equipment is mounted on the vehicle. Many trucks have special equipment and vehicle modifications, Roark said. Pay attention to workmanship when a chassis problem is caused by an accident. Make sure all aftermarket installations and modifications were done correctly.

Damage to Modified Vehicles One possible scenario is a larger engine installed in a truck, Roark said. With a smaller engine compartment, an oval cut may be made in a frame rail because there is not enough room for an oil filter.

"Later, the frame rail breaks causing an accident," he said. "Then the vehicle owner wants your shop to replace the frame rail."

If a dump truck is in an accident and the frame is twisted, more than likely the subframe of the dump body is also twisted, Roark said. Straightening the frame will require removal of the dump body subframe. The frame and subframe are made of different metals that will not bend in the same fashion.

"If the truck frame is straightened without removing the subframe, the softer metal of the subframe may be stretched or overflexed," Roark said.

In a rear impact, the rear axle may be crushed, Roark said. The spring saddle may be pushed down. A leak may develop in this area; so the U-bolts should be pulled off and the spring saddles should be inspected.

Other damage that may not be apparent includes spring leaves, band-out springs, and a cracked spring leaf in the middle of the stack, Roark said. This damage could make a difference in the height of the vehicle if it is not repaired correctly.

"In estimating the damage on a straight truck or tractor, many items need to be inspected and sometimes it's very difficult," Roark said. "To complete an inspection in the field can be very challenging."

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