jumping speedo needle

[yoc]

Hi, I installed a complete speedo cable and speedometer but the needle still keeps jumping. What next?

[Mercedesrover]

Make sure you don't have a kink in it. Make sweeping bends in it as you route it up to the dash. Wouldn't hurt to drip a little oil down the cable either.

[I Leak Oil]

If it's routed without any sharp bends then check to make sure both ends are engaged in their drives properly and check to make sure the rear output flange nut is tight as the speedo drive gear is driven by nothing more than a friction fit IIRC.
Jason T.

[yoc]

jumping speedo needle

Hi, Thanks for the reply Jim and Jason. I don't think it could be the cable being kinked. I'll check the rear output flange nut. Is that the nut with the locking washer just ahead of the od?

[BackInA88]

Hi, Thanks for the reply Jim and Jason. I don't think it could be the cable being kinked. I'll check the rear output flange nut. Is that the nut with the locking washer just ahead of the od?

NO they are talking about the nut in the center of the emergency brake drum, right over where the the rear drive shaft bolts to.
You have to remove the rear drive shaft to see it.
It should also have a cotter pin in the nut you would have to remove first before you can thighten it.

I hope this works for you.
I checked everything on mine before I finely replaced the speedo and all is well now.

Steve

[singingcamel]

I use grafite powder, sounds like a dry cable . make sure the end in the tranny is tight

[yoc]

jumping speedo needle

Thanks guys, cable is new inner and outer. must be in tranny. thanks

[Apis Mellifera]

Is the speedo new?
If not and if the Landy speedo is anything like the ones in my MGs, it's probably the speedo. Most Smith's speedos have a spinning bar magnet that rotates inside a shallow disc inside the speedo housing. The magnetic force drags this disc (rotates it) as the cable drives the magnet. The needle is attached to a shaft that passes through a brass friction bar and then attaches to the disc. Usually what happens is the one side of the magnet weakens and this unevenly "drags" the needle around. There is a margin of adjustment via the brass friction bar. To access it, remove the needle and face and you'll see it. The bar is supposed to dampen needle movement, so if you get too loose or too tight, the needle movement won't be smooth. It might be possible to re-magnetize the magnet, but I've never tried it. You can test the speedo by isolation with a square-drive bit in a drill. Hope this helps.

[Blueboy]

my does the samething - I just use the GPS to tell how fast I'm going.

the speedo is fairly accurate though - it just jumps around a 5mph range.


Jaime

[KevinNY]

Same subject, my Speedo quite working but works when I drive the cable with a drill from the transfer case end?? It started jumping around a bit, got worse then quit altogether.

[LaneRover]

Wait.... ...some of them DON'T jump?

[thixon]

Did you lube the cable prior to installation?

[yoc]

jumping speedo needle

Hi, cable is new inside and out bought new/completly assembled. speedo is also new. haven't checked tightness of nut behind pbrake yet.

[thixon]

If both are new, then my guess is lube, or too small a bend in the routing of the cable somewhere. Don't use a light oil, it just drips down to the bottom of the cable over time Either use a graphite lube, or a viscuss dino lube of some type. I've used lithium grease before because I did'nt have anything else at arms reach, and it worked fine.

[thixon]

I just notice you said you bought the cable new, already assembled. If you did lube it, did you pull the inside of the cable out of the housing and lube it that way?