Speedo not working properly

[Alan W]

The speedo on my 79 (50thousand kilometers) is reading slow and bouncy. I take it up to about 60 - 100kph it takes a long time to get there then stays on the speedo reading even while slowing down. No problems with accuracy, the cables working fine. Any help advice would be appreciated.
Alan W - South Australia

[EMS]

Typical behavior of a speedo that is older and sat for a while without moving. I had one that did exactly this and it corrected itself after a while. No idea what you could do to remedy this. Be careful with generous oiling, you could stain the face.

[steve murdoch icoa #5322]

Welcome to the site, Alan.
Could it just be crud built up at the wheel?
Even with the tight seal at the speedo drive, road grime can seep in.

[NobleHops]

The speedo on my 79 (50thousand kilometers) is reading slow and bouncy. I take it up to about 60 - 100kph it takes a long time to get there then stays on the speedo reading even while slowing down. No problems with accuracy, the cables working fine. Any help advice would be appreciated.
Alan W - South Australia

Welcome Alan!

N.

[Don]

I take it up to about 60 - 100kph it takes a long time to get there then stays on the speedo reading even while slowing down. No problems with accuracy, the cables working fine

Your symptoms are exactly the same as we usually see with tachometers. In my case, adding a few drops of very light machine oil (We have a product called 3 in 1 oil here, usually used on sewing machines and such) around the movable part of the instrument where the cable attaches. I left mine upside down overnight for the oil to soak in and the next day, may tach was behaving normally again. As Mike admonishes, don't overdo it with the oil . . . . a few drops is all you need

Don