The engine did have a top end before I bought it for an unknown reason, but it seems unlikely that it would not have come out in one of the many oil changes.
I don't think it is a threaded chain link anyway. I have never heard of one being used in a chain design. Any engineer who would have come up with that idea should be shot. What would the threaded end thread into anyway? A little nut that would shear or vibrate off?
It is a most interesting little part though.
'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)