Zpeed

Hey Just today i've installed another R200 into my 76 as the last lost the holding pin and cacked itself, this new one has around 1/4 turn drive pinion slackness, and makes a loud noise when pressing the accelerator, is there any way to adjust the slackness or do i have to get another diff. And i am completly sure that it is this noise, as when i turn the shaft i hear the same noise