[Arcuden]

Hello again

Car is a 1970 Nova with a factory 4-speed, and (I think) 8.5" 10-bolt.

There is a rather loud knocking sound coming from the rear of the car, while driving. It is consistent, in that it happens all the time while moving, but not a uniform sound - in other words, it doesn't sound like a broken gear tooth or similar that would make a constant knock-knock-knock sound. The best way I can describe it through text is knock - knock --- knock knock knock -- knock----knock knock -- knock - knock ---- etc. In other words, random. It does, however, seem to speed up as the car speeds up.

Again, it will only make the sound when the car is in motion. Sound does not change if the car is or is not going around corners.

It will NOT make the sound when the following are done:

- Rev the car in neutral with tires on the ground, car not moving
- Put it in gear and spin the rear tires while the rear is off the ground (whether the jack stands are on the frame or on the axle)

It WILL make the sound when the following are done:

- On the road in motion, with the car in gear, with or without throttle
- On the road in motion, car in neutral, coasting

I think I can rule out most of the drive line possibilities (U-joints, drive shaft, differential, etc) but I wanted to ask to see if anybody here knows of any other possibilities.

My only other guess would be suspension, but I can't think of what would cause a noise this loud.

Thanks everybody.

[Arcuden]

Nevermind!

Found out that the cause is a loose shock mount.