ok i have replaced the mustache bushings and put a brace on the diff mount... still clunking. the half shafts seem good and tight but the drive shaft can be turned a good 1/2 inch back and forth. is my rear end just worn out?

 

ok, here's what I'd say...
have you checked your u-joints on the driveshaft? if the u-joints are going bad, then the driveshaft will be able to turn...although I'd say that 1/2 a turn is definitely not a good thing...replace the u-joints if possible, and then if that doesn't work, check out everything else

 

1/2inch of play ... not 1/2 a turn. that would be bad. the u joints dont seem to have any play, the movement seems to be all in the diff. what confuses me is the rear end is quiet other than the occasional clunk. if the diff was truly going out i would expect a lot of whine. who knows, let her go till she blows i guess.

 

ok, well, here's what happened to me. Due to me being a wily teen, and having a fast Z car, I tried to spin the tires, without asking my dad how to do it the right way. Come to find out, I burnt my clutch bad. I noticed that the rear end (differential) would clunk pretty bad when I was taking off, or downshifting, or when I stopped and the clutch wasn't down to the floor. I still have yet to replace the clutch on my car, and before I fried the clutch, it didn't clunk. I guess all I can tell you to do is just to drive it around, try to figure it out, or take it to a mechanic.

 

intresting...dont know how its related but my clutch is not to healthy either. maybe there is something to driveline lash causing the noise.

 

The R-180 Does not have mounted side bearings to hold the spider gear. When the Axles are installed, the axle spindles center the spider. That is why the R-180 is unable to handle any serious power. The half inch of play is due to the input pinion bearing and shims are worn. The R-180 Diff is not worth rebuilding. When you are ready to replace the diff, get a mustache bar out of a 1975-78 280 Z, and an R-200 diff out of an 82-83 280ZX. and get rid of the stock forward diff mount, and replace it with a solid diff mount From motosport auto. This will eliminate the clunking you feel when accelerating hard by getting rid of the stock easily torn rubber stock mount.




Yanky Mate!

 

in australia we get 3.9 R180s with the bolt on half shafts and they have the bearings... best of both worlds !!

 

thanks for the tech breakdown. i am on the hunt for a parts car now.