I have an 84GS without posi. Start up in the morning go down the driveway about 20' hang a hard left and it sounds like the rear end is making al kinds of clunking. After driving a while its not as bad. I have an idea what it is but like some other thoughts. Fluids fresh also. Also sometimes when I go totake off it grabs and chirps the tires.

 

Don't feel bad, no Mazda has Posi. That's a Chevy part.

 

how do you know it is the rear end, maybe you are missing an exhuast hanger

 

 

OK lets not get technical with the words. You know what I mean.