Just got into my first ford, a 2013 F150 4x4 with the one piece shaft. On the initial test drive i did not notice the slip bump but yesterday I did. Did some research and found out to grease the slip yoke. Greased it with valvoline moly grease and seemed to work for the night, today in the morning it felt fine for around 10 min then went back to bumping. It was also around 35ish degrees if that makes a difference. Read more and found a “special” grease ptfe. Should I pull it off clean the grease i used and put the ptfe stuff on or will a new slip yoke fix the issue or do I need a whole new drive shaft? Want to be done with this fast. Also the rear shocks are completely shot and i mean shot they have no dampening to them, would that make the bump more pronounced? Thanks in advanced.