Steve J.

My clunk turned out to be loose harmonic damper sliding back and forth in the torque tube - '87S4

Ducman82

hummm....... how does one check that?

Steve J.

Basically, I eliminated all other possibilities. Then after I sold the car, the new owner replaced TT and verified that's what it was.

Ducman82

ahhhhh.

WallyP

If the spherical washers on the lower arm shock bolt are loose or missing, you will usually get a twitch of the rear end as you get on/off the throttle. The rear will step slightly one way as you apply throttle, then step the other way when you lift off. Pretty noticeable...

Ducman82

everything looks in place. i think i just have a gremlin that like to mess with me.

Mrmerlin

is the sway link hitting the rim??
is the cross member to chassis bolts tight

Ducman82

Cross member bolts are tight, sway link are not hitting. i jacked it up again and removed the wheel and hit everything with a wrench again, all is tight. when i spin the rotor (driver wheel goes backwards) and stop it then move it forward, there seems to be about 1/4 -3/8 "slack" before the diff seems to mesh. but that should be about normal i would think.

Randy V

There is a bolt that connects the right front exhaust support arm to the engine block.

if that bolt is missing, you get a clunk/bang as that support arm hits the block.

Ducman82

nope thats not it.... ill just have to run it some more, maybe get some one to lay in the back with there ear to the floor and listen...

Mrmerlin

add a spacer to the sway links and where they mount

Mrmerlin

to set the sway bar ends connect one side( both ends) drive the car then without lifting adjust the other side so it connects without any preload.

Ducman82

ill try that again to adjust it. the links do have the spacers that came from the kit from Carl.

granprixweiss928

So I have a clunk/knock sound in my RR suspension also. I bought this car a few weeks ago. when test driving, I did not hear it. After a 350 mile trailer ride, the car now makes a knock when going over every bump.

Ducman82, did you solve your problem?

I have read several threads now that all talk about various clunk/knocking sounds in the rear....and none of them seem to ever have the solution posted ( if it was found?)

Im my case, I have checked:


checked all lower suspension bolts/nuts for torque
checked axle nut with large socket, standing on bar
inspected parking brake and shoes- a-ok
CVs seem fine, PPI tech said they may be dry? but they are sealed, no tears in boots
trans output flanges have some play just like Bill ball here:
http://forums.rennlist.com/rennforum...t-flanges.html
I replaced the shocks, the rears were tired ( would not push out when off the car), and fully lubed/torqued the lower link BIG pin and nuts, conical washers
torqued upper shock mount to body nuts
installed a battery clamp
drove with hatch open to see if that was it- nope
double checked exhaust was not hitting frame or CV axles
checked sway bar torques
checked transverse member to body bolts

Car is an 81 with only 56K miles and its a 5 speed shocks are Koni Red and springs are unmarked but look like Eibach.

could it be the fuel tank?

the knock happens with driving around town when going over bumps. noise is a thunk/klunk/dull in the body sound, not a clang or ping or lightweight metal sound.


thx

Lizard928

In Ducmans case, I'd almost bet it to be the shock setup.