Ka-thunk...ka-thunk, ka-thunk...ka-thunk. What is this noise?!?

[Danny_Ocean]

I have a noise (ka-thunk) coming from the front passenger wheel area...typically only happens when coasting or deceleration and upon hitting a bump in the road.

I thought at first it was worn sway-bar bushings. Those have been replaced and the "ka-thunk" continues. Then I thought it was the horizontal cross-brace between the shock towers. I inserted some plastic washers between the mounts and the heim joints...nope.

The only thing left I can imagine is the strut. It's either worn out or bottoming out (rubber stop missing?). How to check for a worn strut? The car handles fine and doesn't nose-dive upon hard braking.

Anything else in that area that "ka-thunks"

[LakeCleElum]

What year? I had this in my 73.5....Front sway bar was sliding back and forth....Was hitting he dust cover of the strut....PO had put in new bushings and had not pushing the linkage into the fender, allowing the bar to "float" back and forth....YMMV

[tobluforu]

Check the gland nut on the strut.

[stormmaster]

oh no.....not the dreaded ka-thunk ka-thunk ka-thunk noise......nothing worse than that....
except maybe the thhp...thhhp....thhhp....hssss noise

[will hung]

Check to see if your wheel bearings are tight. You'd be surprised how they can loosen over time and then kathunk over bumps.

[pete3799]

Originally Posted by tobluforu

Check the gland nut on the strut.

This would be my guess.

[Rot 911]

Originally Posted by tobluforu

Check the gland nut on the strut.

Agree. Had it happen to me a few thousand miles after replacing the struts. Guess I didn't torque it down enough. If it is loose you can get a pipe wrench in there and tighten it down while in place.

[Targalid]

This is also the classic noise made by a loose/failing ball joint or tie rod end, particularly the description of hearing it when going over a bump. Check those for sure.

[shuzboomer]

Does the frequency of "ka-thunk - ka-thunk" change with the speed your car travel? Is it proportional say 10 "ka-thunk - ka-thunk" at 10 MPH and 20 "ka-thunk - ka-thunk" at 20 MPH?

What I am getting at is it a wheel rotation noise that repeats or not...

I had a similar issue with my SC due to some crud in the wheel. The noise went away after pulling the wheel and blowing some compressed air between the pads and calipers.


RBL>

[rusnak]

That's the sound of loose lug nuts as well. Doubt that's the case, so I'd guess loose calipers or bearings.

[Danny_Ocean]

Originally Posted by LakeCleElum

What year? I had this in my 73.5....Front sway bar was sliding back and forth....Was hitting he dust cover of the strut....PO had put in new bushings and had not pushing the linkage into the fender, allowing the bar to "float" back and forth....YMMV

'79 SC. I installed the sway-bar and bushings myself. It is installed correctly. Ka'thunk was there before and after I replaced the bushings.

[Danny_Ocean]

Originally Posted by tobluforu

Check the gland nut on the strut.

Gland nut is which nut? Does the strut need to be removed to reach it?

[Danny_Ocean]

Originally Posted by will hung

Check to see if your wheel bearings are tight. You'd be surprised how they can loosen over time and then kathunk over bumps.

I gave the wheel the "wobble" test when it was on the lift. No play up/down or front/back.

[Danny_Ocean]

Originally Posted by Targalid

This is also the classic noise made by a loose/failing ball joint or tie rod end, particularly the description of hearing it when going over a bump. Check those for sure.

I just installed new turbo tie-rods. Sound was there with the old tie-rods too. Balls joints appear fine.

[Danny_Ocean]

Originally Posted by shuzboomer

Does the frequency of "ka-thunk - ka-thunk" change with the speed your car travel? Is it proportional say 10 "ka-thunk - ka-thunk" at 10 MPH and 20 "ka-thunk - ka-thunk" at 20 MPH?

What I am getting at is it a wheel rotation noise that repeats or not...

I had a similar issue with my SC due to some crud in the wheel. The noise went away after pulling the wheel and blowing some compressed air between the pads and calipers.


RBL>

No, the "ka-thunk" is the same, regardless of speed. It's only change in frequency of ka-thunks is how many bumps I'm running over at the time.

[Danny_Ocean]

Originally Posted by rusnak

That's the sound of loose lug nuts as well. Doubt that's the case, so I'd guess loose calipers or bearings.

I just re-built the wheels and mounted new tires. Lugs are torqued to spec.

Loose caliper? I'll check that.

[tazzieman]

I have the same issue which I had thought might be the ball joint...After new BJs , tierods , bushings(sway and A arm) and replacing upper strut mounts, strut pins, rotors, bearings...noise is still there. Next is to disassemble the strut , even though the shocks are very firm.
Let me know what you find , as I won't get around to looking at mine this weekend!

[rusnak]

Originally Posted by Danny_Ocean

I gave the wheel the "wobble" test when it was on the lift. No play up/down or front/back.

It's always better to check the wheels/ bearings with the car on the ground. Steering might need to be checked on the lift.

[poorshe911]

how about a bad CV joint?

[Danny_Ocean]

Originally Posted by poorshe911

how about a bad CV joint?

New CV joints. Sound is definitely coming from R/F.