My 99 Durango has had a "thump" or knock in the steering column since I had the heater core replaced. I think the shop either knocked the column out ofalignment or left something loose when they had the dash torn out, but several trips back to the shop have done no good. I have tried to re-align the column using a TSB I found on line, but it did not help. The column thumps about every 1/4 turn in either direction. It also feels like it catches or grabs on something. Any suggestions would be appreciated.