I know this is a widely discussed topic but I have a couple of questions. My 87 560sel rides very hard going over bumps. I have replaced the accumulators with very little change in overall ride quality. The pump is indeed working and I was under the vehicle on the weekend and was able to move the vehicle up and down using the hydraulic control arm. I actually took out the linkage bar and manually moved the control arm up and down. However when I replace the linkage it seems like it is too long as I can't raise the control arm high enough to get the car up to the desired level. I did drive the car with the linkage out and desired ride height and it was still rough. My mechanic said I might need new coils but I can't wrap my head around how this would help. Thoughts???????

The Dude.

Taylor Made R7 425 8.5degree(the only other thing I drive)

Is the noise front or back? Only when you hit bumps? I just changed the guide rod ball joint and suspension bracket bushings on my 420SEL. I had a knocking whenever I hit the smallest little bump. Now, smooth as cat fur.

Check sway bar mounts as the bar across will bang terribly when they are bad.

Rough ride is flat accumulators or binding struts, and I cannot imagine the struts binding.

Can you bounce the car by using a foot on the rear bumper, or do the tires just squish out with no suspension movement? If the suspension is rigid, there is something wrong with the accumulators, the fluid moves into them and displaces a rubber diaphram against nitrogen pressure. They fail when the nitrogen leaks out, and there is no suspension movement because the diaphram is up against the top of the sphere.

A loose sway bar will cause the link to be out of position, likely.

Low fluid or a bad pump will cause the rear to sag badly. Dead springs will cause a mushy ride, not a harsh one!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

The harshness is in the rear. Applying force to the back end does make the car move up and down on its suspension as opposed to squishing the tires. I haven't checked the sway bar however. Even when I installed the new accumulators the ride did not soften. It's really a pain as I just had the front tie rods repaired and the front end of the car rides like butter. But around town, even the smallest crack in the road sounds like I'm going over a curb. As this car was the flagship in the 80's and more of a passenger car than a drivers car I would figure the rear suspension should be second to none.