Ugh... I broke something
 

Last week I had the right rear wheel off to take a look at something. When I took was lowering it off the jack, my old crappy jack went down way faster than I wanted it to.

Unfortunately I heard a loud pop, boioioing sound... So apparently I've broken something. big vibration in thr right rear when it drives (which I've ceased).

I put It back up on the jack yesterday and started looking to see it I broke one of the half shafts or half shaft u joints, but didnt see anything.

I was on my lunch hour at work, so I didn't have much time to dig further, however when I lowered it (more slowly than I ever had before), I heard the sound again, a metalling pop, then a boing like a very heavy spring.

I will be digging further today / tonight, but figured I might fish for suggestions here while I'm waiting to dig into it.

1976 280z, 5 speed...

Was the wheel off when it dropped ? I wouldn't think it was that high off the ground when it did drop. What where you looking for, as you mention, in the first place. The only thing's dealing with springs in that general area are the struts and brake shoes

I was trying to get a better look at the fuel pump setup, so I jacked it up by the plate near the diff and then took the right rear off so I could get a better view. The tires were maybe 3-4 inches off the ground.

Coil spring busted? Take a close look. When I hear "boing" I think of springs.

agree... may have been from my crappy jack... but I think this is at least some or part of the issue...


The drive shaft moves back and forth as it goes into the diff...

Danger, learning curve ahead...

Weird... I cant seem to find this part... Apparently they arent replaceable after 1975...

ergh...

As I recall, the u joints are not "replaceable", in the traditional sense, but can be pressed out. See here:
280z driveshaft u joints irreplaceable??? - S30 Series - 240z, 260z, 280z - HybridZ

The boing still makes me think springs. If not broken, maybe it is not sitting square in the perch.

Good luck.

I'm working on some other things now and the car is up on ramps. I am starting to agree on the springs.

Before I put it up on the ramps I jacked up each of the rear wheels and on the passenger side I was able to move the spring up and down freely as soon as the weight was off the wheel.

On the drivers side the spring is stationary and cant move, even after the weight is off the suspension.

This is a bit out of scope for my current project that will have the car on ramps for a few weeks, but will dig into this after. I have some learning curve ahead.

spring
 

Either your spring is broken, or it has gotten out of sorts, with the wheels hanging down, the spring might move and not be seated properly, they really just are held in by gravity / weight of the car.

Rock, I will check into it in a few weeks when get it off the lifts.