I need an educated dart throw. I am feeling a very light periodic vibration at highway speeds that lasts perhaps 1/2 second and repeats about every two seconds. I have not really noticed any change to the period between 50 to 75 mph. Any thoughts? Thanks, Hal

Tires need balanced? Just a guess.

Does it get worse when you accelerate? Could be prop shaft harmonics caused by worn joints or centre bearing?
Eliminate obvious stuff first, check the tire pressure all round and wheel nuts.

No Gary, it does not get worse with acceleration, if anything it might be slightly less noticeable during acceleration/load. Obvious items (tire pressure, wheel nuts, tire balance) have been eliminated. Hal

A cycling vibration is usually drive shaft or center support related. Try removing the drive shaft from the rear end and rotate it 90 degrees and bolt it back up and road test. Get worse or better?

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81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

Did you cure it?
Have a similar cycling vibration - is it worth it to change all the wheels over from my other 190 (Not sure if I've got the socket/strength for the wheel nuts!) or should I be looking to the centre bearing/propshaft balancing due to the cycling in-out nature?

Russ

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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg

W114 does it, W123 did it before driveshaft rebuild. Worn parts or one part is out of phase usualy. If your a startrek fan it's slightly like the throb of the warp core in engenering.

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

A cycling vibration means at a steady speed the vibration lessens then peaks. A tire/wheel vibration stays steady at a steady speed. If it cycles then think driveshaft, stays steady think wheels/tires.

__________________
81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

I solved the vibration problem. The center support rubber had deteriorated allowing the drive shaft to sag when static (can just imagine the dynamic movement) - bearing was ok. The flex disks were functional with very light cracks starting to form. Since getting the drive shaft out is fairly labor intensive I replaced the flex disks along with the center support and bearing. No vibration now! Thanks for the suggestions folks, Hal