Speedometer cable or odometer noise

I have a 1973 450SL (North American model). I am
getting a noise that is either the speedometer cable or else the odometer. Noise starts at about 45 MPH, and will not stop until the car does. At first I thought it was the speedometer cable, but thought I'd ask around before digging into the problem. Car has 117k miles on the odometer. The odometer works, but what concerns me is that the trip odometer doesn't. It, (the trip odometer), will not reset to zero either. Is this a common occurence with these cars? I do have a MB shop manual but with the holidays and all I figured I'd tackle it next year. Any thoughts before I start my quest for quiet?

[JOHNSC16V]

Don

I recently have the same problem with my 86 16V, try do a search first in this area. With my problem people told me to lube the speedometer, so I did but right now I don't know if it work or not because I can't get that damn speedocable back on!! I don't know how hard is it to take out your cluster but try to Lube the speedometer first before you try anything BIG.

John