HELP,SV PRO DIFF & SLIPPER PROBLEM

[toddzellia]

I just rebuilt my slipper and diff in my cougar sv,added new pads new spur gear and new male and female outdrives to diff.I went step by step in the manual put everything together and tried a test run.The slipper was spinning so I tighten it down all the way when car is rasied boath tyres spin and all looks good then went you set it down tyres dont spin and the slipper just spins and car barley moves.
went back tighten the scerw in the diff and still no luck....
any ideas...????