Help, I recently had my trailing arms rebuilt in my 72 along with the 1/2 shafts.

Reinstalled the shims the same way they came out (new SS ones) Used all new hardware, shock mounts etc.

Have not realigned yet.

I developed a loud thumping noise from the P/S when moving in any gear or coasting, it sounds like an out of round condition that appears to happen at every 180 degree rotation.

I drained refilled & added the posi-lube to the rear no change, changed the snubber also. Differential mount bushing are tight.

I'm considering repositioning the rear spring it appears to be off to the P/S about 1/2" too far. The rear spring outer mounting bolts are not centered in the spring bushing, I believe this might be adding to the problem?

Does anyone have another suggestions? I'm at my wits end and hoping it's not a differential issue.

Alex

Is P/S.  Propeller shaft?

IF you had the Drive/Propeller Shaft out of the rear, check to see if the end caps on the universal joint are properly seated in the pocket and the u bolts are tight on the caps. If you have side or up and down movement on the end of the propeller shaft, something is not tight, or not in correct placement.

Make sure that the tailshaft of the transmission is on a parallel plain to the input shaft on the differential.  If these are not parallel, there will be a vibration since the driveshaft will speed up/slow down with every rotation.

Thanks I plan on getting under the car this weekend and look. 

MMM didn't think of that will check

Check to see if the spring end is hitting on the rim, or a wheel weight. You should be able to see wear marks if it is...

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Well guys thanks for all your help. 

I believe I did solve the issue, apparently when I had the local auto repair shop press in new universals on the 1/2 shafts, they had not properly secured the flange, needless to say it was bent at the top of the ears and this caused the thump at 180 degrees, the cap was not in line with the end of the universal and the retainer was not fully seated in the recess on the flange, I straightened the ear replaced the holding cap retainer with a new one test drove and all is fine so far.

Shame on me for thinking the local auto repair shop could do the job right. 

Great!  I've been in that situation myself, and noticed the problem as I began the I installation.  Glad I could point you in the direction that I have encountered.  Be safe, drive it and enjoy it! 

Great!  I've been in that situation myself, and noticed the problem as I began the I installation.  Glad I could point you in the direction that I have encountered.  Be safe, drive it and enjoy it! 

I think it's Passenger Side. I first thought it was Power Steering until I read farther. 

1973 L-82 4 spd