I replaced all the struts , shocks (koni fs) and mounts about 10,000 miles ago and recently started getting a rattle over bumps fr the rr . I removed the rear shock and tightened the top bolt about 3/4 of a turn and the noise is 80% gone . Im wondering if I should disassemble the shock to see if the top mount under the cap is bad . Any suggestions appreciated

 

Upper factory shock mounts are worn and they clank around. When putting in new struts makes sure you get new rear shock mounts. 33526754123

https://www.northamericanmotoring.co...int-knock.html

 

Thanks for the reply . I did replace the mounts front and rear with a new set when I installed the struts and shocks

 

Only thing I can think of is if the mount is bolted all the way down on the FSDs. The insert on the rear should have filled any gap. Did you check the rear sway bar and the sway bar links? Also the rear control arms?

I would check those first, then go back to the rear upper mount.

 

I checked everything and it all looks good so perhaps Ill just change the upper mount since its really not that difficult to do
thanks

 

ok, welcome.

 

Frankiev, Wondering if you replaced the rear upper guide supports and did it fix your knock? I have a similar knock on my '05 MCSC with Koni FSDs. I've replaced the upper bushings with Powerflex but that made no difference. Knock is coming from guide support area. Almost like top of support is flexing. Video below was before I put in PF bushings.

 

All I did was tighten the top nut on the shock mount which had backed out a few turns