For about a year now, I have been having a clunk sound. I knew the ball joints were bad so I figured it was that. Well over the weekend, I grew some ***** and replaced the entire front end. Here is what we replaced: New upper/lower ball joints, inner/outer tie rods w/ sleeves, pitman arm, idler arm, end links, both shocks, both hub assemblys, both axles, brakes, rotors, & calipers. Took about an hour and half to strip everything down and took about 4 hours to put back together (taking the time cleaning parts, doing it right).

Well the clunk sound did not go away. When I press on the brakes and the vehicles weight shifts forward, it clunks and I let off brakes letting vehicle come back up, it clunks. The sound is coming from the passenger side front end. I know its not the brakes because I capped off the brake line and it still makes the sound. It actually does it with out using the brakes if you hit any holes or what not. Bouncing the car up and down does not make the sound either. Only when there is heavy jerks of force then will it make the clunk sound.

Now I am thinking possibly a torsion bar mount, control arm bushings, motor mount, transmission mount? I dont know. I have energy suspension control arm bushings but I didnt put it because it looked like the torsion bar was going to be a bitch to get out and the upper control arm bushings were siezed to the bolts themselves so I knew it was going to be a nightmare.

When it makes the sound, its like its coming from the rear part of the torsion bar. Its not isolated to the very front of the truck. Its almost like its right under the passenger seat floor area at the bottom of the door.

I dont know... any ideas on ways to check? I was going to have an alignment done but am going to old off until I figure out the issue.

By the way, its a 1998 Chevy Blazer 2 door 4x4 w/ 206k on stock ball joints (rivets). Also, last month, we just did lower intake manifold gaskets on it. Pretty easy job if the EGR tube comes off ok, which it didnt which turned into replacing the driver exhaust manifold. It never ends! Im so deep into this thing, I cant stop. New fuel tank, fuel pump, rear brakes, tcase, blah blah blah

 

I know this sounds kinda funny, but open your hood and hold it on either corner. Rock it from side to side. Do you hear your clunk when you do that, or is it solid?
The hood hinge washers are bad for going on these trucks. It makes a horrible clunking noise. It's a tiny little washer that takes 5 min to replace. Hard to believe that's what causes such a bad clunk. Anyway, just a suggestion. It happened in my truck too, so you might want to start by testing that out.

 

x2

These are the washers -- Dealer only part, and the hardware stores around me did not have a conical washer like this in such a large inner hole diameter.




The hood hinge problem makes more of a shock/balljoint clunk...it usually happens with a little more frequency. The torsion bar crossmember bushings also can go with high mileage, but that's usually one hard clunk, and will not clunk again until the weight shifts significantly again in the other direction.

Edit: Just saw the part where you said it was like it was coming from under the passenger floor. That would almost definitely be the torsion bar crossmember bushing. But the hood fix is a quick $10 fix for an annoying sound

 

I missed that under the floor comment. It's probably not your hood washers then.
Hard to believe, but those washers literally fit on your finger tip and they're about $5 each at the dealer.

 

I thought it was my torsion bars too, took 2 rags put under the hood hinge to load the hinge upwards when closed, took it around the block and NO NOISE WTF this used to be a silent recall now they dont give a rats *** i call them Obama hinges.

 

Well the sound is gone... here is what I did, I got an alignment.

I dont know what he did but whatever he did made the sound go away.

Camber was perfect within .3* of each other to 0*
Caster was out 3.8* & 4.5* and they adjusted to 3.1* and 2.7*
Toe was out .54* and .47* and they adjusted to .04* & .03*

I am assuming its whatever he did to adjust caster that fixed the problem. I dont know what but when I picked the truck up, I pressed the brakes and it didnt make the sound. So I hammered the brakes trying to make the sound happen and it wouldnt clunk.

2 weeks later, I blew up my motor. Keep an eye out for that thread haha

 

WOW, the internet saves the day again. I've had this clunk in my ZR2 for months, Thought it was a ball joint but when I looked underneath it wasn't loose. Put the rag in between the hood and the frame took it for a ride down a dirt road.
EUREKA moment indeed.

Now if I could only get better gas miliage!