speedo question

1929tudor

Senior Member
Just got my car done and finally the madien voyage. I saw that my speedo jumps around. say if I'm going a constant 10mph it will bounce from 5-15mph just from the roughness of the road I guess. Souldn't it be still?
 
It should run smoothly. I suggest that you start with the speedometer cable. Make sure that it is lubricated within the housing and fits without binding into the receivers on both ends. I have seen a few that had a drive cable (in the housing) that was too long and would compress slightly when installed. Gar Williams
 
make sure there are no sharp bends in the outer cable, or a clamp isnt to tight and crushing the outer cable
 
Be very sparing of lubricant within the speedo, too much can gum it up. The cable should be lubricated with a graphite based grease, not a chassis grease. Remove the inner, clean off the existing stuff and apply a good coating of graphite. Reassemble, test, good to go! :)
 
1929tudor,
I have this exact problem in my 1929 Sport Coupe. What did you find the problem to be? Thanks. Jim
 
1929tudor .................
Vaseline is very good for lubricating the internal cable. It does not get stiff, when cold, as regular grease does, and it does not run when it's warm. You can use it very liberaly. It has been used for decades and decades.
Remove your cable, clean it well and use plenty of vaseline, as you feed the internal cable back in.
MIKE :)
 
The internal cable is made of a spiral wound bundle of spring wires. If one of the strands fractures (very common) it will rotate with a jerky thump no matter how well it is lubed. Get a new cable core. My dad worked for Stewart Warner on Fullerton Ave. in Chicago in the early 60's, where they made speedos and cables. Chrysler was a big customer. The cable off the ball mill winding machines was tested for evenness of strand tension and rotational speed when bent and rotated. The good stuff went to Chrysler, the reject stuff went into Schwinn bicycle speedos. Every year my bicycle had the latest Chrysler dash with a great big 120 mph speedo.
 
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