Police officer, "Do you know how fast you were going back there, sir?"

Me, "Somewhere between 10 and 60 mph. I really couldn't tell for sure because the speedo was boinging all over the place."

Yes, my speedo is boingy, especially in the first few minutes of driving (it calms down a bit after a while). No, I haven't actually been stopped by the police.

Is this just a matter of a new speedo cable or do you think there's something up with the dial (or maybe dodgy electrics)?

It's a Smiths dial, by the way. The trip counter is jammed, although the odometer works.

Thanks,

Cable might just need lubricating. I belive it's graphite or something you're meant to use.

I tend to agree - I'd take both it and your clutch cable out, hang them up somewhere and liberally squirt WD40 down between the cable covers and the cables letting the fluid flow out of the bottom. You'd be suprised at how much browny gunk will come out....

V6 Man wrote:You'd be suprised at how much browny gunk will come out....

Reminds me of when I had that kidney infection.

(Sorry, you didn't want to hear that )

kidney stones are far more fun Gavin especially when they are bigger than the "pipe " they have gotta come out of ( bet you didnt want to hear that either)

Ouch, oh yes, been there, done that!

Horrid. Absolutley horrid lol

The closest men can get to the pain of childbirth, apparently

V6 Man wrote:squirt WD40 down between the cable

This is not a good idea! WD40 attracts moist, and when if freezes and you drive off your cable snaps. Just use something like bicycle oil.

Wd-40 is a great rust solvent though So yeah, I would WD40 first then 3 in 1 afterwards

WD40 attracts moisture? really? but WD40 stands for "Water dispersant 40th attempt" it was developed by a research chemist in his spare time.

The boingy speedo is also caused by a bad earth on the cable.

The 340s tend to go bouncy as the earth fails. A way to check if you have a bad earth ( although it only works once in the cars life ) is to check if your heater heat selector sliider has become stiffer to move, more than usual or if the choke cable has become much harder to move. This is caused by these cables being used as earth cables when the one from the speedo stops working. The slight heating of the lining of these cables as they act as earth cables makes them stiffer to move.

check the earth straps both to the battery, the stater, the one from the bonnet to the front of car and the contact between the earth strap need the battery the bolt that holds it to the area beneath the battery.

good luck!

The speedo on 300s is purely mechanical, trust me. I've had 'em apart. But yeah bad earths cause lots of problems.

Yup, lube the cable.

cheers

James