I recently noticed my car was riding about 3/4" low in the driver's rear. Today I crawled under there expecting to replace a soggy shock and found this:



:eek: :eek: :eek:

I replaced it with a VBP part that looks a little different than the factory unit. It's the same width from end to end (it doesn't flare out beyond the central hanger-onner), it's thicker in vertical section and doesn't have as much arch, basically it looks like a black 1x2.

Due to the shallow arc, at maximum suspension travel in the downward direction there is literally zero preload, the knuckle bolts are loose. In reality, this condition should only exist when the car is airborne, in my case that's not all that often.

The original spring used four spacers on each side, two aluminum plates and one pressboard plate on top and one aluminum plate underneath. The new spring is much thicker in the center, in the absence of any installation instructions, I used only the pressboard spacers to arrive at a dimension slightly larger than the original (accounting for some squish in the old one) and it seemed to snug up nicely.

Does any of this sound right, or should I expect an abrupt change in ride height in my very near future?

 

Sounds like you need to call VBP. :cheers:

 

Great photo....what an ugly component. According to Dave McLellan, that "spring" was flex tested over a million times without failing in the lab. :confused:

Was your spring exposed to any "solvents"...engine degreasers, etc.?


[Modified by Oldman, 9:43 AM 7/24/2003]

 

sometimes exhaust heat can cause this type of spring failure, too.

 

:iagree: Look at the exhaust, no heat shield like the factory setup

 

As far as I know, the exhaust is factory up to the welds you see just under the spring, wasn't any additonal heat sheilding prior to the modifications. No doubt that original spring had been cooked for 100K+ miles.

I've heard about solvents disintegrating fiberglas matrix, but this thing didn't just turn to mush, it has a distinct and almost perfectly straight break at the tip. This leads me to believe there might have been a manufacturing defect, possibly a misplaced seam in the fiber.

Toward the end of the spring, there are some whitish abrasions that look suspicously like jack saddle marks, you can guess what effect that might have.

Another possibility is there is a band in the middle of the halfshaft that is very clean, as though something rubbed the oxidation off. I'm wondering if something didn't get wedged up there long enough to shorten the spring over a few bumps and weaken it at that point. My power steering cooler was kinked into a perfect 90 when I bought the car, so I know there's been at least one large foreign object under there.

The guru at the Corvette-only parts store said skipping the car laterally under power can do that as well as abrupt changes in traction, such as spinning off ice or sand on to sticky pavement. I'm gonna say we're all right; it was a combination of the above.

I've always inspected the leafs from above (try getting your head under there without a hoist) but I'm going to keep a closer eye on the dirty side in the future.

:cheers:

[edit] still can't type... [/edit]


[Modified by rocketfinger, 2:03 PM 7/24/2003]

 

Hmmm? You have one?

 

The original y-pipe on my '88 did have a heat shield where it makes the 45* angle after the cat. When I had a new one fabbed up, I didn't have one put on, but I am thinking about it when I eventually get around to duals. The heat shield on the original was about 16" long where it goes under the spring :cheers:

 

Just noticed that. Hmmm...