Likely the parking pawl is bent, I'll bet it goes click, click click as it rolls too. It isn't nearly as beefy on the 108's as it is on the later cars like a 126. Or could be the shift bushing inside the steering column if column shift. My 4.5 will only catch in park perhaps 25% of the time. I always use the hand brake with that one.

__________________
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.