Strange noise coming from my rear end
 

...and no, it's not flatulence...well not this time anyway.

I've got a loud metallic CLACK.... CLACK... CLACK..CLACK CLACK. CLACKCLACKLACKACKACKACK sound coming from the left rear corner whenever I get hard on the power. The frequency of the clacks increases with speed, stops when I ease off, and is especially noticeable while accelerating into a left turn from stationary. If I drive easy I have no problem. No noise or vibrations cruising the highway.

Car is a stock 84 GSL 110K/km, with original bushings, 25K/km on shocks

Any thoughts?

does the noise stop when you apply the brakes?

I suggested this to someone else,

In my race car, after I lowered it and took ou the Watt-Link and installed a Panhard bar, the drive shaft rubbed the tunnel under extream acceleration and cornering. I didnt have the rearend lined up! Check out all of your bushings and watts link. Look up in the drive shaft tunnel, if it is the drive shaft, you will see the rubbing marks.

Thanks Guys

1st Seven... Had a leaky pinion seal replaced in the diff not too long ago. Noise started afterwards. Will check drive tunnel for scuffing.

inittab...Noise stops when foot eases on accelerator. Haven't tried left footing the brakes while getting on the power. What's your line of thought here?

After I took everything out of the rear interior of my car, I heard my poor driveshaft making a thumping rhythm and a constant clicking noise. I also hear a loud CLUNK whenever I shift - old driveshaft, soon to be replaced. All I've got to figure out is the rear axle.

could be a caliper binding and causing the pad to make the clacking noise, or one that's overly loose and rattling.

What Manntis said is my line of thinking

Check your tranny mounts too. If they are getting bad/loose the tranny will become misaligned and might make that sound. But this sound come from the middle of the car. <-- Just something else to check after you exhaust all other possibilities.

Thanks for the replies all.

If only all problems had solutions as simple as this one...Turns out that the noise was an inside wheel weight clipping the E-brake cable on each revolution. Surprising how loud it was.

Did you replace the crush collar on the pinion shaft when you replaced the seal? I sure hope so. ANYTIME you remove the pinion flange a new collar is a MUST. It's a one time use item. How's the clutchpack in your LSD? WHen they wear out, they make a sound like you describe. When you refilled the diff, what did you use? Did you use an LSD additive? If not that'll make for a noisy clutch pack too.

Yeah check out that stuff, LSd additive will make a big difference :)