Speedometer repair and adjustment with pictures

[pullshocks]

My Vision developed a screeching sound when in motion.  By riding around the block without my helmet I was able to tell it was coming from the speedometer.  Another clue something was wrong was the eratic response of the speedometer needle.

There are several threads mentioning speedometer noise and the need to lube the cable and the bearing inside.  I tried lubing the cable, to no avail, so I opened the instrument cluster and pulled the speedo.

Speedometers have always been a big mystery to me.  The cable spins a magnetic disc.  which causes a second disc (actually kind of cup shaped) to rotate.  The second disc is on the same shaft with the speedometer needle.  The faster the magnet rotates, the farther the needle moves.    There is a very light spring on the needle shaft that returns the needle to zero (visible in the 2nd photo).

I lubed the bearing, but in this case the screeching did not come from the bearing.  The threaded portion had come loose from the frame, allowing the magnet disc to rub on the other part.

Using laquer thinner and q-tips I cleaned the joint and glued it in place.

My speedometer has always been wildly inaccurate (reads 45 and a known 30 mph).  The odometer has been reasonably close.  As long as I had it out, I wanted to try to get it better calibrated.

I used my electric drill to spin the speedometer.  It advanced the odometer .6 miles in 1 minute, equivalent to 36 mph.

By bending tab that attaches the spring to the frame, I increased tension on the spring bit by bit until I got the speedometer reading down to 36 mph while spinning it with the drill.

We will see how accurate that turns out to be on the road.

[QBS]

I do believe that you have gone where no Vnary has gone before.  Thank you.  Did you remove the speedo needle in any of your explorations?  If so, how did you do it?  Conventional V wisdom (and my personal experience) has indicated that sure speedo destruction lies down that road

[pullshocks]

Did not try to remove the speedo needle.  Seemed like that would be inviting disaster.

[Rick G]

My experience with speedo needles is that they can be removed easily . just be gentle. Tach's are different matter . If you try to remove them it will destroy the tach. When i replaced the face with a custom stick on , I made a cut from the bottom of the face to the shaft hole  and them applied the stick on face.

[lexx790]

I corrected mine the same way, a good way to check its accuracy is to ride with a sat nav or a speed app on a modern mobile phone.

[pullshocks]

You win some, you lose some dept:

Don't have a GPS or smart phone but I went through a couple of the neighborhood radar trailers that flash your speed, and 28 on the speedo was 28 on the radar.

Unfortunately, the noise came back after a couple miles.  I can feel it in the speedo cable housing, and tweaking the cable makes it go away.  So I am going to try to source a new speedo cable.

[Rikugun]

Is it the cable or did the glue fail? Did you remove the cable and examine it?

[pullshocks]

Glue did not fail.
That needed to be fixed, but apparently I was wrong concluding the noise was caused by the rings rubbing together.
I pulled the cable out, no fraying or anything.
I got some different lube, white grease in an aerosol can from NAPA. 
After shooting a bunch of the white grease in there, and putting the cable back in I disconnected the cable at the wheel and spun the cable with my drill.  The noise was intermittent.  I could feel a lot of vibration at the cable housing but could not isolate the sound.
After spinning with the drill for a few minutes, the noise stopped.  I reassembled and rode 5 miles with no noise.

[QBS]

Did you pack the cable carrier bushing mounted in the speedo head unit with grease?  That fix has been promoted several times over the years.  It worked for me.

[pullshocks]

QBS, I tried to work grease into the bearing, and I thought I succeeded because there was no noise spinning the unit without the cable ( drill with a small phillips screwdriver tip  inserted where the cable goes).  But it is possible that I did not get grease all the way in.   I will try again with the  aerosol white grease, it comes out very liquid and may flow into the bearing better.  It has some solvent content and thickens up as the solvent flashes off
I may also try Rick Greville's trick of drilling a lube hole, but I worry about drilling too deep and buggering the bearing.
If the noise comes back I will also try the new NAPA cable core that i bought before discovering the complete cable is available from Yamaha,

[Rick G]

Just drill slowly and check the depth frequently!I did it with the speedo on the bike . '83 style fairing was mounted as well . Its not that hard.