Hi Manfred
I have similar problem. My 67 230sl doesn't lock in park, and wants to roll. I always use a wheel chock. Lever appears ok. Where is the spring/pawl on the output shaft? Can I access it and lube or see if spring is present? 1971 Lancia, do you have a picture? I remember my college roommate lusting after the Lancia Beta when it came out. I was more intrigued with the exotic Stratos rally call, but I have never seen one. Any help or info about the trans would be much appreciated.