Wasn't trying to pick on you...just bein' funny.
Anyway, I think it has something to do with the steel portion of the assembly compressing a little upon being installed the first time. Once popped out, when you try to reinstall them, perhaps in a different bearing bracket, I expect they didn't fit quite as tight. Result, now they 'thunk'. If you installed the complete bearing bracket from the donor car, with guide rod mounts unmolested, then it is most likely someplace else.
Better
__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.