Rear end Trouble

Need some help, I have a 2001 model 2500 dodge truck 4x4 5.9 cummins. Problem the rear end give me problems. I think it's a dana 70. Had the clutches and the 4 small gears replaced. Now when I turn the inside tire does not free spin but keeps pulling, the additive was put in the oil, took it back to shop it was pulled apart and clutches soaked in oil for an hour, put back together, better but still no free spin when turning on blacktop. Any help appreciated.