1979-1993 & 94 Conv [Subscribe to Daily Digest] |
Hi, Toshi
New shocks will definitely make a big difference. I think I can help explain the harshness you're feeling, and it's not a SAAB design problem. Your SPG didn't ride that harshly when it was new. I noticed the same thing in my 900T before I changed shocks last year.
Shock absorbers damp out two different kinds of oscillation in two different ways. Low frequency/ long throw oscillation, such as when you bounce your car by pushing down on the fender a few times, are damped by the shock absorber piston moving up and down. When this damping mode fails in a shock absorber, a car will continue to rock and oscillate after you let go of it, perhaps bouncing through several long cycles like a Slinky toy.
The other function of the shock absorber is to damp out high frequency/ small amplitude vibrations. At the top of each shock is a small rubbery "donut" which isolates the car frame from vibrations. Over time, these dampers can harden into solid little hockey pucks, and then you will feel every tiny imperfection in the road.
Many times these dampers are bad, but the shock still performs the long-throw damping function adequately. An inexperienced mechanic might bounce your car a few times by pushing on the fenders, see that it damps out quickly, and say, "Your shocks are fine." But he's not testing the vibration damping ability.
I'm oversimplifying this a little; there are multivalve shock designs and other exotic and expensive shocks which can handle high frequency oscillation within the shock body. But for a typical shock absorber, the rubber donut on top handles almost all of the short period vibration damping.
When you install your new shocks, make sure you don't overtighten the nut on the top of them, squishing those little donuts too far. With new rubber dampers on your new shocks, you will immediately notice the harshness in your SPG's ride will be cured.
Good luck!
- = M = -
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