Suspension Vibrations

[Eagleyez]

Can damaged coil springs, frame, or frame parts (metal fatigue/hairline cracks) cause vibrations in the suspension, dashboard, and floorboards?

2002 AWD Astro Passenger Van used (789 miles) at purchase. From day one, we felt a mild to moderate vibration, a "soft" "cushy" ride, and wandering at freeway speeds. Within a few weeks (highway driving) the front end began to shake and wobble at higher speeds and it felt like the tires were leaving the road surface with any "bump" in the road causing the steering wheel to Jump/Bounce up and down.

In 8 months I had the vehicle back to the dealership for service (steering problems) 6 times. The repair history (attempts) is a nightmare alone.

Anyway, the short story: they ultimately discovered the driver side door pillar welds were broken, both passenger side shocks were "blown-out", and the passenger side tires had "Broken/Separated" belts. However, they tried to suggest that brake wear and warpped rotors caused the vibration. They tried to sell me a brake job!!!

They replaced the front-end parts (including the brake/rotor issue) and the vibrations are still there. At the same time, exterior body trim parts and interior trim parts were tightened and or replaced; caused by excessive vibrations.

Now they suggest the vibrations are inherent to the AWD Van.

:mad: I took the vehicle to an independent shop. The inspection confirmed the vibrations but revealed no VISIBLE damage to suspension or front-end parts. However, with the history above and as this vehicle was used in the Winter Olympics (2002) in Utah, the technician advised me that if the vehicle had left the road and had landed hard on the suspension, or suffered any type of sever impact, there may be minute/hairline fractures/cracks in the coil springs, frame, or frame parts. According to the technician, this could cause vibrations that would be amplified by the steering wheel and other driver compartment components.

Help? and thank you.

Eagleyez:confused:

[Wayne]

Hello Eagleyez,

It definately sounds like you have a problem with this vehicle.
I can't imagine that the problem would be within the springs (hair line cracks), as due to the nature of spring steel, it will just snap rather than develop small cracks.
With the infomation that you have stated, it is consistant with the symptoms of cracking in the chassis or suspension, and with all the other problems that were discovered, you would have to be seriously concerned with the history of the vehicle, and what sort of impact it has been in. I would recomend finding a good chassis and suspension specialist to have a look at it and try to find any more signs of broken welds or cracks in any of the components.

I hope this helps you.

Wayne
wayne@whiteline.com.au

visit our web site at www.whiteline.com.au

[Eagleyez]

Originally, I thought owning an Official Olympic Vehicle ... (it was only used to shuttle dignitaries).... was a novelty. Come on, ...(it was used so little, only 789 miles, they returned it to the Manufacturer to be reconditioned, then it was sent to us).... The Salesman must have been the guy that came up with the Little Old Lady from Pasadena sales pitch. Really, that was a good one!!!!

I have learned that all steel has hairline cracks. However, it is when the smaller cracks begin to travel, connecting to create larger cracks that you will have problems. A severe impact will cause the cracks to move, which will begin the loss of integrity in the steel. This will, depending on use, speed up the process of metal fatigue. Although weakened, the steel may not break, but depending which component, or combination of components was damaged, may still have an affect on performance in other areas; steering, vibration dampening, weight capacities, and so on.

I have talked with engineers, spring manufacturers and automotive (GM Qualified), and was told that any impact resulting in blown out shocks, separated belts, and broken structural welds, would likely have had an adverse effect in the structural integrity of the entire vehicle. However, without the previous history of the vehicle and with no specific dynamics known, the formula for measuring impact loading would be a guesstimate. Therefore, all structurally related components would need to be investigated, some through destructive methods and others through the Non-Destructive Method (ASTM-E-1444).

In any case, they tell me that the impact would have been severe enough to cause great concern. The consensus was the springs may have suffered damage, but this alone would not create all the vibration that I am experiencing. Moreover, they felt it was likely a combination damage to other parts of the suspension and in structural areas as well.

I have an appointment with the General Motors Engineer tomorrow morning. It will be an interesting discussion.

I'll be back with an update


Eagleyez :cool: