I am tired of this clunking sound from back end

[AnlaufJohn]

I finally have Lucy's Limousine back on the road and during a long drive last weekend, I felt and heard a clunk from the back end that occurs when turning left or right, after a change in forward movement, say coming to a stop.
The parts I have replaced over the years include:
both trailing arm bushings, stabilizer bar bushings, drive line carrier bearing and inspected the inner gears of the differential.
I doubt the shocks are making that kind of shift, I mean this movement affects the whole truck. It is almost like a short power slide without the power.
The u-joints were inspected when the carrier bearing was replaced and Mike is the drive line guru in town. I trust his judgement.
The bed has new bolts holding it to the frame.
Braking does not affect, but acceleration does.
Moving from a stop, either fast or calmly, and turning, will cause the noise and jolt.
Any ideas on where else to look? Everything seems tight where needed and loose and movable where movement is needed.

[Sharps40]

On my truck that same sound at the same times is the tailgate chains.

[63burban]

Check all bushings on the control arms and track bar. Then check for rust out or cracks in the control arms and broken "U" bolts or other broken/cracked parts. Also check the crossmember that the control arms mount to and check for cracks in the frame itself.

[donthekawguy]

Also check your pinion bearing.

[Clyde65]

check your rear end gears. sounds like something may be in there.

[luvbowties]

Sharps' reply seems to fit the criteria--like sounds when accelerating but not when braking. Think about chains normally riding with wt. against sheet metal: braking keeps them there with even more force, while accelerating causes the truck to initially "run off and leave them"--first swinging them outward.

You did not mention another poster's suggestion: check the track-bar [pan hard bar] bushings. You may have covered this when you mentioned "stabilizer bar"? The track-bar, too, could fit your scenario.

One hint you may concentrate on while diagnosing is twisting/torquing force. Ie, no noise when braking--which yields straight line stopping with body and drive line kept straight; but noisy when accelerating--which yields engine-twisting and torquing force, with drive line twisting simultaneously. Generally, driver side motor support 'breaks' first due to engine torquing up-and-away from its resting position on its mount-and-pedestal, with greater movement; passenger side torques "onto", or "against" its resting position on mount-and-pedestal, with less movement.

Good luck on finding source.
Sam

[hotrodder]

if you have a posi-trac rear, it could be the clutches slipping as you turn. my truck did what describe, I changed the grear oil and replaced it and added the posi-traction additive. problem solved

[Sharps40]

I also put pcv grommets over the chain tab ears so when closed the tail gate doesn't go bonk, clunk, doink, skronk, broing, rattle, rattle, rattle......

[Shaky]

Check the U-bolts that hold the rear axle to the control arms (if you have coils). Mine were half the diameter down in the control arm due to rust. My buddy's broke on I-95 in CT!!!

[AnlaufJohn]

I found out today I have a limited-slip rear end. Who would have done that to a truck with no A/C, no arm rests, one visor and the economy heater? Somebody must have replaced the rear end, because I have the build sheet and there isn't any mention of limited-slip or Posi-Track on it.
I didn't think about taking a picture while the cover was off and my mechanic buttoned it all up when I returned from an errand.
We added the additive and I drove it around and no loud popping sounds!!
I feel a jump or nudge now, so the super dooper goo must be working its way in between the friction discs.