Klunking noise is driving me insane...

[87NAT]

I have had a klunking noise coming from the back rear drivers area for about a year now. This is what I have done:

checked all sway bar bolts
tightened all shock bolts.
put rubber line on top and bottom of coil springs to dampen them
checked all exhaust/muffler clearances
put rubber groments on all exhaust hanger connections and bolt holes
checked tires for rubbing etc, etc, etc, etc....:frown:

Could I have a bad body bushing and it will only rear its head when I am going down the road. I am almost 99% sure its a metal on metal noise but very deep sounding. Only during bumps or uneven roads does it make this sound.

Any advice you have is appreciated. I only have 35k on the car but it sat for many years in storage before I bought it.

 

[3.8L V-8 eater]

I have had a klunking noise coming from the back rear drivers area for about a year now. This is what I have done:

checked all sway bar bolts
tightened all shock bolts.
put rubber line on top and bottom of coil springs to dampen them
checked all exhaust/muffler clearances
put rubber groments on all exhaust hanger connections and bolt holes
checked tires for rubbing etc, etc, etc, etc....:frown:

Could I have a bad body bushing and it will only rear its head when I am going down the road. I am almost 99% sure its a metal on metal noise but very deep sounding. Only during bumps or uneven roads does it make this sound.

Any advice you have is appreciated. I only have 35k on the car but it sat for many years in storage before I bought it.

Had a friend who had the same type of clunking noise you described. because his exhaust rattled a little he thought nothing of it when it got worse... So a buddy at a car show put his foot on the exhaust and the noise didn't stop... Ended up being the bolts that held the torque converter to the flexplate had all came loose. He was able to tighten them up and still drive the car , but he rounded off the holes in the flex plate so he will be replacing that at some point. Could be worth a look didn't see that on your list of things you checked.

Tony...

 

[87NAT]

I have had my tranny out and switched converters 4 times in 2 years. But thats another story....
Noise has remained constant thru out tranny installs.

 

[GNVYUS 1]

Make sure gas tank is flush against the trunk or it might make that clunking sound.

It's not a spring compression sound or bushing squeak?

 

[Pronto]

Is the jack and spare tire stowed correctly in the trunk? They could be making noise.

 

[87NAT]

Is the jack and spare tire stowed correctly in the trunk? They could be making noise.

Thats extra weight and has been gone for years.

 

[87NAT]

Make sure gas tank is flush against the trunk or it might make that clunking sound.

It's not a spring compression sound or bushing squeak?

I will check my tank but I am sure its tight.

As far as the spring compression sound I really dont know. From inside the car it sounds like its coming from the wheel well area or by the back seat. Its not inside the car but thats where the klunk is coming from. Thats why I want to now suspect a bushing maybe. I just didnt know if they will do that or not.

 

[Pronto]

Do you have the 2 extra body bushing (the GNX) ones?

 

[87NAT]

Do you have the 2 extra body bushing (the GNX) ones?

They actually came with the car. The original owner bought them and never installed them. I have them in a box in my garage. Would that make a difference? IS it hard to install?

 

[Pronto]

I've never done them but I believe you would have to loosen all of the mounts and drop the frame enough to squeeze them in.

 

[JST A 6]

Had a friend who had the same type of clunking noise you described. because his exhaust rattled a little he thought nothing of it when it got worse... So a buddy at a car show put his foot on the exhaust and the noise didn't stop... Ended up being the bolts that held the torque converter to the flexplate had all came loose. He was able to tighten them up and still drive the car , but he rounded off the holes in the flex plate so he will be replacing that at some point. Could be worth a look didn't see that on your list of things you checked.

Tony...

"Had a friend"??? I'll still be your friend even though you keep using my car as an example on here Tony!!! J/K:biggrin:

87NAT, make sure you check the transmission crossmember mounts where it mounts to the frame rails too. I once bought a truck that was making some pretty awful clunking noises and the guy I bought it from had no idea what it was so he dropped $200 from the price so I could use that money to fix it. Turns out the crossmember mounts were shot and I fixed it for about $30. If you don't mind spending more HR PartsNStuff has some real nice poly crossmember mounts; That's what I have on my GN.

 

[HyperV6]

My 85 Monte had a sound from the rear / trunk area. After taking the back seat out and checking everything under the car I finally found it. A spot weld on the trunk latch mechanism broke where it attached to the inside of the trunk. When I would hit bumps or drive on uneven surfaces it would make the noise. I welded a couple of small beads and no more noise. Check it out.

Craig

 

[jdpolzin]

Sounds to me like control arms. Either the bushings on the top of the rear end, bushings in the control arms, or wobbled holes where the arms mount.

 

[87NAT]

"Had a friend"??? I'll still be your friend even though you keep using my car as an example on here Tony!!! J/K:biggrin:

87NAT, make sure you check the transmission crossmember mounts where it mounts to the frame rails too. I once bought a truck that was making some pretty awful clunking noises and the guy I bought it from had no idea what it was so he dropped $200 from the price so I could use that money to fix it. Turns out the crossmember mounts were shot and I fixed it for about $30. If you don't mind spending more HR PartsNStuff has some real nice poly crossmember mounts; That's what I have on my GN.

I have had that crossmember in and out ALOT in the past 2 years. I will look at that.

 

[87NAT]

My 85 Monte had a sound from the rear / trunk area. After taking the back seat out and checking everything under the car I finally found it. A spot weld on the trunk latch mechanism broke where it attached to the inside of the trunk. When I would hit bumps or drive on uneven surfaces it would make the noise. I welded a couple of small beads and no more noise. Check it out.

Craig

This sounds like it could be it. Because the sound is coming from that backseat area. Of course I am always driving and its hard to pinpoint a sound when your behind the wheel. I would get my wife to help but she wont ride in my GN anymore. After I lit up the tires at 50 mph and went sideways real bad with her in it she vowed never to ride in it again. The plan worked. I can cruise solo now.

 

[87NAT]

Sounds to me like control arms. Either the bushings on the top of the rear end, bushings in the control arms, or wobbled holes where the arms mount.

I changed the lowers out. How can I check the top ones with out pulling them? OR do I need to pull them. I dont mind the work, just asking.

 

[mr_nate]

I have that same annoying noise now, checked it out yesterday, bushing was split and hanging off on the lower control arm

 

[SS_Sean]

You might also pull you driveshaft off the pinion yoke and check the play on the pinion. A couple things could be wrong if you have exessive play, bad pinion bearings or the too much play in the ring/pinion. If that's the case a rear end rebuild would be necessary.

You could also have bad u-joints on the drive shaft. Easy to check. Crawl under the car and if you can grab the drive shaft and move it there is a problem.

You could also have an output shaft bearing that has gone out. This would cause exesive movement in the output shaft on the tranny, and would cause a clunking noise when shifting from gear to gear.

Hope that helps.

 

[EGOKILR]

I am having the same problem

Only over bumps. My buddy said it was the bushings for the car, all of them look fine to me.
I have another rear end I needed to upgrade so I swapped that one with new upper adjustable control arms to get rid of the stock control arms, I have Metco lowers. The drive shaft did seem to make the same sound when I was under the car hitting on it towards the tranny and rear end side. I believe it is what SS_Sean stated to look at, just seeing if you found your problem?

 

[VIN7]

Did you check the parking brake cables just in front of the driver's side rear wheel?

Mike