"Slow" dometer woes and noises

My speedometer AKA the Rover Slowdometer, which is there to remind the series driver of how slow they are going is making a tremendous noise. WIth out any intervention at all, yet, it will occasionally make a loud noise and the needle will act more irratically than usual. I might assume that A, the cable is not fully engaged in the back,, or the gear mechanism is shot and they are not engaging, or some other type of Rover ghost is in effect. Ill figure it out, but wondering on and taking suggestions. Cheers.

No suggestions yet?
Well, the only thing I can offer is a somewhat similar experience (though without the loud noise) resulting from gearbox oil somehow working it's way up the spedo cable (Archimedes Screw effect?) and into the spedo head. That resulted in the needle jumping all over the place...

Thanks 88 I too thought it would get at least one suggestion, but. Thanks, sounds right oil contaminating the gears gumming it up, time to take out and clean, and I think I have a spare which I need to locate,

I've had this happen in a few of my other vintage cars. I've always taken a bolt out of the back of the speedo. Squirt in a little oil. Put the screw back in. The sound is gone.

The gears inside a speedo dry up over 50 years. They need a good lubing. The proper way would be to take apart the gauge and lube up the insides.

I have found that sometimes the lubricant in the speedo cable hardens up and caused the cable to whip around causing wierd noises and needle fluctuations. Light oil run down the cable usually fixes that type of problem.

i've tried to make a fitting to force grease up the cable but to no avail, it always ''come apart'' self destructs. Some industrial equipment has a grease fitting on their cables but not seen much any more. I've soaked them in diesel etc., the best fix was to afix a funnel to the cable in a vertical position (on a high ladder) and fill the funnel with kroil. it'll take a week but it makes it through ........ but then you need grease, not penetrate oil !

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Originally Posted by jimrr

i've tried to make a fitting to force grease up the cable but to no avail, it always ''come apart'' self destructs. Some industrial equipment has a grease fitting on their cables but not seen much any more. I've soaked them in diesel etc., the best fix was to afix a funnel to the cable in a vertical position (on a high ladder) and fill the funnel with kroil. it'll take a week but it makes it through ........ but then you need grease, not penetrate oil !

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You can always fit a new cable, use grafite, its dry and wont attract dirt. I just replaced my speedo cable and after the problems you described decide to try graphite.

Also check that the nut on the transfer box rear output shaft is tight . The drive worm gear to the speedometer is only clamped between the flange and bearing. I had the distance to work suddenly reduce by 10% when using my 2A , it was the gear slipping.

As it sometimes goes with these small annoying things on Rover Smiths gauges, the problem went away, will most likely rise again in the future.

Try checking to insure the cable isn't kinked and binding. It'll build up pressure, release, and jump all over each revolution. I had an old Triumph Spitfire with this dreaded "Made in Britain" issue... for a definition of MiB, watch "The IT Crowd - Series 1 - Episode 2: Fire!"