67 Valiant

When I had to remove the rear wheel clyinders, I had to remove the axle shafts. When I was done putting the wheel clyinders, I put the axle shaft, and I had a buddy check the oppsite side if the other axle was rotating. It did. Then I mounted the brakes. When I test drove the brakes, the rear end did something I never heard. It felt like the tires moved first, then the car moved. I didn't do a burn out, I just gentley relesed the clutch. Was I suppose to remove the diff cover and algin the axle shafts? Its a /6 (170) 3 on the tree. It's got a 7 1/4 rear end. The rear end didnt do a grinding sound, it just felt funny.