w126 Rear suspension HELP!!!!!

hi
i have been having an issue with my 85 500sel lately. when the car is under load with 2 people while driving, i feel a nasty shake and it makes a hum. also around 60mph i feel a vibration under the driver's
seat.
took the car to the dealer yesterday and had them look into the driveshaft. the both flex disks and the center support bearing checked out fine. final diagnosis was that i need to replace the rear subframe bushings and rear upper control arms. they say the rear end is loose. come to think of it, when i go over bumps, i can hear
My questions: why the control arms? do they bend after 200000mi? isn't it the bushings? how manay are there?
any ideas?
thank you in advance
Lushan Silva 85 500SEL
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Your five arm, multi-link rear suspension definitely could cause your car's symptoms. MB has upgraded the outer, top arm with a much more heavy duty one as well as a newer designed bolt. This arm bears the brunt of the weight when cornering. P.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.