It has a harsh, yet sloppy, ride

Question:

I am having a problem with the ride quality of my restored 1985 Oldsmobile Delta 88 Royale. When I rebuilt this car (just as I have several other similar GM vehicles), I separated the body and frame and replaced all the body mounts with good rubber and steel inserts. I’ve replaced the springs, both front and back, so many times and in so many variations that I’ve emptied the salvage yard. Yet, despite all of this intense and exhausting effort, the ride quality is actually getting worse.

The vehicle does have some evidence of salt corrosion, but nothing so serious as to impair its structural integrity. Currently, all four springs are exactly original equipment part numbers, albeit from other Oldsmobiles or similar vehicles. The original front springs had sagged to the point that they needed to be replaced. The car rides over, rather than through, lumps and bumps and gives a harsh, jarring, jolting ride that is devoid of any isolation. When going into a depression like a manhole cover, the car dips heavily into the hole and the back wheels impart a very uncomfortable and abrupt punch to the chassis when coming out. When going over any slight irregularities in the road, one can actually see the hood ornament and headlights wiggle and jiggle up and down with the terrain. It feels as if I’m being dribbled inside of a basketball, and a series of bumps in the road can send the car skittering out of control.

Naturally, I’ve tried so-called “heavy duty” shocks, but those only made the ride so bad that I had to turn back and remove them within one block after installing them. Going over the slightest ridge or fissure in the road yields a harsh and loud “crack” that can be felt through the seats and steering wheel as if the suspension is not absorbing any of the road irregularities.

And, despite all of this stiffness, the car handles poorly with sloppy cornering and side-to-side toss that can make the driver motion sick. I’ve tried using stiff urethane sway bar links, but the added suspension stiffness made the car even more intolerable to drive. I’ve also installed a rear sway bar, but that did nothing for the ride.

I have several other mid-1980s Oldsmobile Deltas and Buick LeSabres, all of which ride like a dream. They all have the exact same springs in them that this car does. One of them has suffered substantial rust damage to its frame at critical points, yet despite its high mileage, it rides like new. I’ve had to replace its springs several times over the years and almost no matter what salvage yard spring I threw at it, it rode perfectly thereafter.

I have done literally everything I can think of to try and smooth out the ride on this car. The only clue I can give as to what might possibly be wrong is that when replacing the front springs (an arduous and time-consuming task), I could barely hold the front lower control arms in their fully extended position even with all of my weight while grabbing the lip of the fender well to push against. Both control arm bolts had to be loosened for me to get the compressed spring into the frame and arm. Normally, as with other similar vehicles, I could just use one foot to swing the arm down while slipping in the spring or loosen only one bolt and easily move the arm down to install the spring. In this vehicle, the rubber control arm pivots seemed to have the fight of 10 men in them.

Because the rear springs do not require unbolting the lower trailing control arms, I cannot tell how stiff they are. It is my understanding, though, that these rubber pivots, unless damaged by outside forces, should last the life of the car. I replaced the motor and transmission mounts, and despite the harsh, pounding ride, you cannot feel the engine or transmission vibrations.

Does the very metallurgy of a frame deteriorate over time such that it becomes unable to resist vibration and shock inputs? Is there any hope for this vehicle other than a “for sale” sign? It looks great and is easy to maintain, but I’ve got to do something about this ride. What is going on here?

Answer:

I have a few comments that may be of use to you. As you point out, it is something of a chore to replace the springs. Because of this, and because the actual performance of used springs cannot be gauged until they are installed, I always recommend installing new springs when feasible.

Having said that, I don’t think the ride problems you are experiencing are due to bad springs. Your car’s control arm bushings were not meant to “last the life of the car.” Like any rubber parts that are subjected to intense loads, they eventually will need to be replaced. Bad control arm bushings can definitely be at least part of your problem.

Furthermore, bad installation practices can adversely affect control arm bushing performance. When you need to pivot the control arms beyond their normal range of travel, such as when you replace springs, you should loosen the bushing end cap bolts. Don’t tighten the bolts again until the springs are installed and the car is on the ground bearing its own weight on its wheels.

A possible problem with control arm bushings is that they can get rusted in place. When you separate the ball joint, remove the spring, and loosen the bushing end cap bolts, the control arms should pivot freely. If they don’t, it likely indicates that the inner sleeves are frozen on the pivot shaft.

You state that the car “wobbles and bobbles down the road” and this sort of behavior may result from bad or incorrectly adjusted wheel bearings, loose or broken suspension parts, a cracked chassis or incorrect wheel alignment.

And last, don’t overlook the importance of the role your tires play in ride and handling characteristics. Defective, excessively worn, unevenly worn or just plain poor quality tires can yield a horrible ride. The same is true for the shock absorbers. You mention that you tried “heavy-duty” shocks and they made the problem worse, but don’t say anything else about the shocks you have in the car.

There is a big difference between bargain shocks and high-quality units and if you have the former get rid of them and install four new, name-brand, high-quality gas shocks.