GOOD NEWS ! Since no one provided me with an answer to my question, I decided to tackle this project myself. Rather than taking the dashboard apart, I decided to investigate the transmission end of the speedometer cable/housing first. I followed the housing under the hood from where it came through the firewall down to the transmission. I was able to get at it fairly easily without even having to get under the car. Where the housing meets the transmission, I found a dust cover rubber boot (similar to where an ignition coil wire goes onto a coil). After 17 years, it was pretty well stuck, and I had to slit it with a razor blade to get it out of the way. I was then able to see where the cable housing went into the transmission. I had expected to have to unscrew it, but I found it was being held in place by a retainer spring clip. I released the spring clip and was then able to gently pull the speedometer cable housing away from the transmission. As I pulled it out a few inches, I saw that the inner speedometer cable was still in the transmission. I stopped pulling the cable housing and gently pulled on the inner cable. It came right out of the transmission. I then pulled the speedometer cable all the way out of the cable housing. It came out easily. I sprayed some WD-40 into the cable housing, added a little bit of heavy weight (80-90) gear oil and then sprayed in some more WD-40. I then put the inner cable back in the housing and gently worked it back and forth, pushing it in and out to evenly distribute the lubrication inside the cable housing. I finally pushed the inner cable all the way back up into the speedometer. Then I inserted the bottom end of the housing into the transmission and reattached the spring clip. I finished by replacing the rubber dust cover that I had slit with the razor blade. The toughest part of this whole process was getting the spring clip back on to lock the cable housing into the transmission. It was a tight spot to get at, and took some trial and error and patience. I'm waiting for some really cold weather, but thus far I haven't heard any more speedometer noise. I think this did the trick.
Tuesday, February 19th, 2008 AT 1:35 PM