Mechanics

QUESTION ABOUT SECONDARY OR INDIRECT DAMAGE DIAGNOSIS?

2007 Dodge Caliber • 50,000 miles

The vehicle was hit in the drivers side wheel well crush zone. Since the design of unibody is meant to absorb energy in the crush zones from the front or rear collision. How is the energy transmitted when it is hit directly?

The vehicle was going west and another vehicle(going north) hit it in the wheel well, destroying the wheel, ripping the shock and strut in two.

How do you determine the path of indirect damage?

Photo Note: The bumper and grill removed for damage analysis.

Issues: leak in coolant, under engine case, oil leak located near coolant tank. Engine vibrations, squeak in the back end, brakes grinding
all doors misaligned, hood misaligned increase wind noise drivers side door - also rattles, knocking noise in passenger side wheel well, loss of acceleration, ticking when accelerate, whirling noise from serp belt.

What happens when the unibody is off by 12mm and over tolerance in 6 other areas. What issues arise when unibody is off.


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Olivernmari
February 5, 2012.



You need a mechanical engineer to answer questions like these. I have a friend who rebuilds only smashed Chrysler products and he never concerns himself with these questions. He hooks it to the frame straightener and pulls things in the direction they need to go. There are numerous locating holes under the car where he takes measurements from. With those, it is very easy to get things correct within 1/32", but that can be hard when sheet metal is severely wrinkled. In those cases, he cuts off panels at the welds and installs new or used ones.

As a body man, he is very aware of crush zones that must not be beefed up with extra bracing, but must be as strong as original to provide proper support.

Caradiodoc
Feb 5, 2012.
Thank you for you answer. We had the frame measured and it's out of tolerance in 7 areas out of 24, one area is more than 12mm. I'm not to sure what happen when the frame is out of tolerance though.

Tiny
Olivernmari
Feb 5, 2012.
12mm is a lot in some areas and insignificant in others. The important things are the position of the lower control arm and the upper strut mount or upper control arm. Those suspension items have to be in the correct geometry for proper handling. An alignment can appear to correct the wheel for good tire wear but it takes more than that for good handling.

Doors, fenders, and the hood all have adjustments built in to overcome production tolerances so you don't have to worry if those mounting areas are off a little. If the panels seem to fit properly, I would mainly be interested in seeing an alignment printout. "Camber" is the main alignment angle that has to be set very precisely for proper tire wear, but for good handling you need to look at "steering axis inclination". That angle is not adjustable and there is no spec. Given. All that is important is the angle has to be the same on both sides, within 0.2 degrees. If it is not, the front cross member might be able to be slid sideways, or sometimes the upper strut mount can be shifted a little.

Caradiodoc
Feb 6, 2012.