General Tech Speedometer Pointer Bouncing Around

[arcom]

I forget where online I read it, but the inner cable is only supposed to extend out like 3/8"---not exactly sure about that number---but it was way less than my cable protruded. Someone had suggested loosening the knurled nut where it fits into the back of the speedo which I did and it greatly reduced the waving---but did not eliminate it.

 

[ed_h]

Since it is reading too high I doubt it is an issue with the magnets as that would mean they are too strong. More likely the spring has weakened

I think this is correct. My magnet had weakened, and I was able to strengthen it, but in the learning process, inadvertently weakened it, which suggests that a weakened spring might be compensated for by weakening the magnet. If you're game, this might suggest how to do it:

https://bullfire.net/TR6/TR6-40/TR6-40.html#Speedo

Ed

 

[KVH]

I just wanted to close this topic out by saying that, as a few of you indicated here, the only problem was a bad cable from one of the big three. It was too long, and whether that was the sole problem, I don't know. But the new shorter one, routed over the top the engine, then down along the tunnel cover on the passenger side, out of the way of the exhaust, works fine. I have an angle drive and overdrive transmission, just fyi.

I should stop always assuming something more serious. My Speedometer is almost perfect. And, by the way, TJ's Speedometer Service here in Tucson was great. He tested it right after I walked in, and didn't try to sell me a thing. His bread and butter isn't Smith and Jaeger gauges, but gauges off more modern trucks. Interesting guy. They're not making many more like him.