Speedometer needle bounce

My speedometer cable bounces at slow and fast speeds. About 5-7 mph. I replaced the cable and housing, lubricated with spray graphite and it continues.

Is the likely suspect the speedo or the right angle drive?

I don’t see how gears can cause a speedo to bounce. They either turn or they don’t, there is precious little room for them to bounce - nowhere near enough to affect the gauge.

First, remove the speedo, and file a nail square so it fits into the socket for the inner cable on the speedo. Chuck the nail in a variable speed cordless drill, and spin it. Typical cordless drills run about 300 RPM max which, IIRC, will indicate about 50MPH. If the drill can drive the speedo up to it’s max speed without bouncing, the speedo is fine.

Next, completely remove the cable, and flush both pieces out thoroughly with solvent to remove any and all lubricant, then re-lube it with good, clean oil. Again use the cordless drill to drive the cable and speedo, and see if it bounces. Try to bend the cable to the approximate shape it is in when in the car. If it bounces, then you probably need to replace the cable.

When re-installing the cable, find a position/routing that minimizes the bending along its whole length.

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Ill give the drill a try. Was going to try that before but the cable seemed to be constrained so i replaced it.

Good to hear your comment on the drive gear. Limits the causes.

So brand new clean cable/housing and graphite lube, no gunk to flush. It routes in nice smooth transitions and cable was free all the way down until dropping into drive.

I had this on my mgc. The angle drive was slightly worn so the speedo cable was slipping. I bypassed the angle drive to test it and it worked fine so ordered a new angle drive and all was good. Not saying this is your issue but worth a check.


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OK, yeah I see what you mean. I’ll give the drill method a try and then check out the angle drive if the Speedo checks out. Gotta pull the console to get to it so delaying putting that back in.Preformatted text

I once had the sam problem and took cable out and greased it. Big mistake.

Soon the speedo went funny. All the grease worked its way up into the speedo due to the cable pumping action.

69 OTS

Mine used to bounce. Lubed cable. No help. Tried the drill method. No bounce. But it did bounce inthe car. Problem was in the speedometer, it was binding. With the drill drive. It over came the bindig. But with the cable, the binding would wind up the cable, then release then wind up. Causing the bounce. Cleaned and lubed the speedo, the odometer part was tight.


Or you could just plug a digital speedo into your fag lighter . Oops sorry , this an E type :grimacing:

Same on my E. Eventually the drive became completely rounded and didn’t rotate the cable at all

Larry, you talking about rounding on the Right Angle drive at the tranny or the Speedo drive cog?

Tom, so drill method may not give me a definitive answer I guess, but may as well give it a try.

You can easily determine whether the angle drive is damaged. If it is, you’ll be able to turn the output shaft while the drive is still connected to the gearbox.

Correct, the speedo needle was steady with the drill, and the speedo part was okay. But obviously the same cable drives the speedo and the odometer. The one gear in rhe odometer was sticky in its bearing. That caused the cable to wind up to overcome the binding, then release at once making the speedo needle jump. Then it would repeat.

It was the right angle drive off the tranny. The female square hole for the cable end wallowed out and became totally round when it failed for good


So, more than one problem may cause the condition, what a surprise!
Guess i better take another close up look at the angle drive too. Almost feel like buying one-you know the old “throw parts at it til solved”. Not the smartest method I guess. Trans cover on but console still off so nows the time to check it.

Anyone use one of the aftermarket drives available from SNG or others?

Trying to get the Jag’s little issues wrapped and make some progress on my Sprite eng. It’s calling me.

I thought about using the cheaper one SNG offered but in the end, bought the “OEM” one for twice the price after hearing complaints about the cheap ones. YMMV

Yeah, my recent experience with the repro turn signal makes that make sense I’m afraid.

Our speedometer needle was bouncing wildly at slow speeds and would moderate down to a +/- 5 MPH waver at speed. I removed the speedometer from the dash to observe the rotation of the speedometer inner cable. It appeared to rotate smoothly when driven and was not binding/releasing at slow speeds. I then turned my attention to the female cable input spindle on the instrument. I placed a small flat blade screw driver into the square hole and rotated the spindle. I found the issue in our instance…The lubricant between the speedometer casing and the female input spindle had become stiff/hard and I could feel resistance when I rotated the blade. I VERY LIGHTLY applied 3 in 1 machine oil (about 20W) to the periphery of the female cable receiver and rotated it using the small screwdriver. This freed up the 50+ year old lubricant after a drop or two. I keep an old cable end in my tool chest for testing cable driven instruments and spun the speedometer up using my cordless drill…the needle’s operation was smooth throughout the RPM range that I could apply. You don’t want lubricant to find its way into the instrument. As soon as I applied a drop of oil to the periphery of the input spindle, I turned the instrument over (cable input spindle facing the ground) and rotated the spindle back and forth. Judicious use of lubricant and gravity kept the lubricant from entering the instrument body. The speedometer needle operation is very smooth now.

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When I bought my car the speedometer was not working. I pulled my angle drive and took it apart. Found that there is a small length of cable in there and mine had twisted in two. I am going off 20 year old memory but I took it to a friend with a welder and got things hooked back together and working ever since. Your’s may not be repairable but might be worth a look inside if you are not keen to buy a new one right away.

68 E-type FHC

Thanks you guys. I will be taking a look at both those issues.

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My speedo was totally fine then one day it started to bounce. After two days the speedometer stopped entirely.

Taking off the right angle drive I see that the end cap came off and some of the internal parts de parted the vehicle not to be found. This was a part that the po had his mechanic replace so, I don’t think it was that old.

I put a couple of blobs of JB weld on the replacement but I haven’t put the car together yet to see if it actually works well.