Date registered: Nov 2008
Vehicle: 1981 300TD 310k--1966 230 165k--1970 280se 172k
Location: Ohio City, Ohio
Mentioned: 1 Post(s)
Quoted: 33 Post(s)
A '68 220D is a w114, right? I think that it shares the same horn arrangement with the fintails with the exception of a collapsible bowl between the wheel and the horn (the last year or so of fintails also had this bowl, I believe).
If so, it may have missing/worn vulkonnan washers in the shift column that causes the horn to malfunction. When these are faulty, they cause the shaft of the shifter to overtravel, thereby pushing the horn ring into contact when you don't want it to. The parts are cheap and is a pretty easy fix. Replace the nylon ball washer at the shifter stalk while you are at it.
There is a DIY article floating around somewhere that should help with the procedure. It involves removing the steering wheel, the bearing snap rings, a couple of hex screws, the shifter stalk, the turn signal assembly, and the retaining clip on the shaft, which has to be rotated with vice grips 180 degrees to release the clip.
Be careful prying off the horn pad. Instead of removing the logo, the whole pad pops off by pulling out with your hands. Before I knew what I was doing, I tried prying off the logo and slightly damaged it.
1981 300TD--310k miles
1970 280sel--172k miles
1966 230--162k miles