BluYot

We were driving yesterday for an hour and a half, avg cruising speed of 100km/h no hills, things seems to be running really well no vibrations or symptoms that something might be wrong. When I was reversing into a parking spot I was naturally look back, then look forward again and noticed a trail/cloud of smoke. I felt sick. It smelt a bit rubbery and a bit like when someone's brakes are dragging and since I just had the rears all redone that was my initial thought but they weren't even hot or have any evident damage. Then I thought maybe it was the center support bearing, or the rubber part within it. When I first bought the truck and was getting it safetied, the mech. said that it would need replacing within the year but not to worry it won't leave you stranded. Is it even possible for this to start smoking? We drove back today avg. 90km/h and stopped a few times but there was no sign of this mysterious smoke...although there was a very mild vibration going faster than 100km/h. I'm boggled but am ready to order the CSB as a preventative measure and u-joints were also replaced/inspected. Any thoughts or opinions on this? Is there a big difference between the aftermarket and OEM CSB? Thanks.