I am trying to find the cause of a hard knocking when going over bumps in my 86 560SEL. I have raised the lever on the valve manually to watch the car raise/visually inspected the struts for leaks/changed the accumulators.

I still have the knock and want to change the top and lower bushings on the rear struts but i can not find them. I believe the part #'s are

114 326 00 68-top
115 326 16 68-bottom


I found https://www.pelicanparts.com/More_Info/1153261668MBZ.htm?pn=115-326-16-68-MBZ&bt=Y&fs=0&SVSVSI=3481
but that says top of strut and i believe that is the bottom bushing. Should i just order 4 of those?


Any advice on other things to check are also appreciated but i do plan on replacing the bushings so if anyone knows where i can buy them.