Have a 71 GS with cruise. Old speedo was way off (15 mph). Replaced gears in tran and cables. Still off. I replaced the speedo gauge and it worked correctly (right on the money compared to GPS). Now the speedo intermittently stops working. If I spin the cables at the cruise unit the gauge works. If I spin the cables at the transmission, the gauge works. When I hook it back up it will work correctly for a few miles then stop again. Any ideas? Thx.
Are the speedo cables new or old and have they been lubricated? It sounds like the cable(s) are binding. Also the back of the speedometer itself can occasionally use a light cleaning just to be sure there is no unnecessary drag on it. Lastly, the ends of the cables are box shaped, they could be worn out and rounded off.
New cables, lubricated, ends are square. I oiled the back of the gauge when I put it all together a month ago or so.
Replaced the whole system (gears, cables, and entire gauge). Worked fine for a month then started this intermittent failure. Everything was new except gauge, which was used, but it works fine when spun by hand or with a drill.
Not at the same time. Replaced gears and cables trying to get speedo close to accurate. Then realized the speedo gauge was no good so replaced it. After that if worked great (read exactly the correct speed), then started this business.
So I figured out the problem. The 2 gears in the transducer were not meshing up correctly. They both spin on a brass bushing. I hammered the brass bushing for the lower gear out a 1/4 inch, and now it works fine. Guess I need a new transducer, but at least the speedo works again. Not sure I would trust my life to a 50-year old cruise control system anyway, as I never use it.
