Bouncing Speedometer

Unknown

What causes the needle to bounce on the speedometer. Depending on the speed I can get up to a 10 mph bounce on the needle.

Pat

RL Chilton

From my experience, it's a dirty housing and cable. The cable sticks, then lets go and sticks again, etc. It causes your needle to "bounce" all over the place.

Jon B

You might slide the flexible cable out of its sheathing and inspect it. If there is a kink in it, that might explain the bouncing. Then you could lube it at the same time.

[Deleted User]

Hi Pat,



Most likely the speedo cable is dry. Disconnect it under the dash at the speedometer, then pull the cable up, and out of the housing. Be sure to spread some old towels, sheets, or newspapers over the floor, and seat so you don't risk the cable getting oil residue on your interior when it is removed. Coat the cable with gear lube if it's a standard trans, or trans fluid if an automatic, then slide it back in the cable housing, and button it all up. If that doesn't do it, the speedo mechanism in the dash may need a little light sewing machine oil applied to the revolving parts inside, which will require the speedometer to be removed, and opened up.



Hope this is a help.

Unknown

Great fast responses. I thought I had lubricated it when I installed it, but I will check again and if it is not the cable I will lubricate the speedometer lightly.

Thanks guys.

[Deleted User]

If you do lubricate the speedo itself, please do so very "lightly".



I made the mistake of lubricating one "heavily", the excess oil got between the two drums of the speedo and caused it read very, very high. The speedo is an air gap arrangement and doesn't tolerate interferences well at all.



There is some really good cable lubricants that are used for motorcycle cables. NOX is one I've used alot. The applicator is a small needle that you can insert between the cable and its housing, then squeeze until you see the lubricant dripping out of the other end. I'm in agreement with the other posters, try lubing up the cable first.



Mark

Geoff

I had the same problem on my Jet, and it was caused by the cable being too short (I had fitted an overdrive), and the routing made too sharp a bend. I fitted a longer cable with a smoother bend, and it cured the problem. However, the same thing can be caused by a binding speedo head as has been mentioned. This causes the cable to wind up, and then whip, resulting in the variation.

[Deleted User]

My speedo has done this in the past and after lubing the cable, what I found was lack of lubrication at the dash gage. My 1951 Commodore has a small hole with a cotton wick right where the speedo cable screws into the gage. It looks like a brass bushing that spins with the cable. A few drops of oil and it smoothed right out. I add a few drops every year of so when the needle stars to wander around.

Browniepetersen

OK, with all this good advice there is little for me to say. But, I will add, with my 52 the lube and the spedo housing lube did not solve the problem so I pulled out the housing/cable and removed the cable from the housing. I soaked the housing in fluid and took a light paper (400 grit wet/dry) to the cable. while I was sanding and cleaning the cable I noticed two small nicks. I cleaned these up, ran an abrasive brush through the housing. Soaked the cable and housing in a graphite based oil and reassembled. Wiped it dry and reinstalled it. It has worked great for about 4 years now with just a bit of graphite on the cable each year.