Rear end problem help

Howling on deceleration can be a loose pinion bearing ! In that case you will need to have the pre load on the pinion bearings readjusted ! Friction Modifer will fix the clunking noise ! You just need to drive it ! Go to a school parking lot and do some figure 8 with it! The clunking is the friction clutch’s grabbing and letting lose again! Once the modifer gets on the clutches good that will stop !