At this point in time, I've changed all of the bushings. That includes the mustash bar, and the rear diff. front mount. I've changed the drive shaft U-Joints, and the half shaft U-Joints. One of the drive shafts was starting to go bad. The two lower half shaft U-joints were getting a little bad.

Guess what? I still get a lower decible, low pitch CLUNK:mad:

I can't believe it. A complete master bushing set. And lately, all these other parts, and still a slight clunk. Could it be one of the carrier bearings behind the oil seals, that were also changed in the diff??? Could it be something in the rear brakes??? It's diffenetly behind me.

I noticed the slightest amount of oil seapage behind one of the oil seal in the diff. So while changing the u-joints, I had the seals changed also. Oh, yeah, a new clutch while I was at it. New front oil seal, and gasket in the tranny also.

Oh why, oh why :disappoin Is it too much to ask for, to have a clunk free car:cry::disappoin

Did you replace the arrestor strap?

Been there, dude. My advice? Don't trust your ears. These cars' body structure (IMO) make most noises sound like they are coming from the rear. I spent months chasing a 'clunk in the rear', only to finally determine that it was in the transmission instead.

So stop now, and take some detailed notes. When does it clunk? Only on torque application? Or will it clunk back when you back off? Is it temperature related? (i.e. only when the car is warm, or only cold)? What gears will it clunk in? Can you get it to clunk in reverse? Any more or less likely to clunk while turning? These are the types of things that will help us help you track it down.

Could also be stub axle splines. They wear and can clunk.

Pre-internet days when I had my first 240z I tracked down a clunk to the right hand side stub axle. I just crawled around under the car feeling for any play in the joints. Started with the propshaft, to the diff, then each drive shaft to the wheels.

Found the slightest movement in where the driveshaft bolted to the wheel.

Not sure if it was the right thing to do, but I just tightened the big nut up and the clunk went away.

i have a very slight clunk in my 240. only when i start out in reverse, then stop...shift to forward 1st gear.

however, after reading a lot of posts on this issue, i'm going to wait it out until it gets REALLY LOUD and OBVIOUS.. LOLLOLLOL

I hear it mostly after the car has sit for awhile. It seems to rear it's ugly head when I try to back up after the car has been parked for awhile.

I just put that theory to a test though. I can hear it going forward, and backward. Only at very slow speeds. As in just moving a little from a complete stop.

As per SBlake's question,,,no, I didn't change the strap holding down the top front of diff,,,,,If indeed that was what was inferred by arrester strap.

Had a similar problem awhile back (fully restored drivetrain and suspension similar to you). My "thunk" was from an incompletely secured spare tire. I doubt the arrestor strap is the problem.

As Arne said, don't trust your ears.

I spent HEAPS trying to track down a thump in the rear right suspension. At least that's where the noise APPEARED to be coming from. Had it apart no less than four times. Finally fixed the problem by adjusting the #@&*^%@!~* SUNROOF.

I can laugh about it now though.

Rick.

:devious::devious:

As Arne said, don't trust your ears.

I spent HEAPS trying to track down a thump in the rear right suspension. At least that's where the noise APPEARED to be coming from. Had it apart no less than four times. Finally fixed the problem by adjusting the #@&*^%@!~* SUNROOF.

I can laugh about it now though.

Rick.

:devious::devious:

my approach justifies my procrastination since i'm 80% deaf in my left ear.....plus...i spent enough time and money on my car for now:bunny:

Somebody recently mounted a videocam under their car trying to find the source of a noise too. Perhaps this might help some? It's a great idea, and if it ever stops raining here I want to do it too, to capture the sound of my car under heavy acceleration because with only a resonator and no muffler she really screams above 3,000, but silent below with a soft foot.

Good luck tracking it down.

yeah...that video was me

http://classiczcars.com/forums/showthread.php?t=31266&highlight=thunk