I still think the left lower ball joint is had it. The key is his initial description about rumbling when curving right at highway speed. As the ball joint deteriorates the first perception is a very minor shimmy during this manuever, then the steering wheel begins to visibly move followed soon by a low rumble. If left unattended it will develope into a rumble with an almost harmonic knock.

When mine started I thought I needed an alignment, but since the tires were wearing pretty even I let it ride. When the rumble started I did the front end rebuild, everything except the LCA bushings.

__________________
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.