Lotus Elan and Lotus Elan Plus 2 Forums

The speedo needle on my `67 S3 elan wavers +or- 5 to 10 mph. Is this normal or is it likely to be wear in the head, or the cable?
Jim

Possibly a kinky cable.. a common problem on many cars.. or
the cable may be sticking.. easy enough to take out and clean..
or either cable could be slightly rounded
alternativly it could be the gearbox drive having a tooth or two missing.. not tooo hard to check.. but check the cable first.
also the right angle drive can play up....

I had this problem on my S4. Fitted a new speedo cable and it fixed it. Make sure the cable does not have any sharp bends/kinks. As a new cable is only about ?10 I would start here first.

Yes change the cable otherwise if it's tight you will end up ruining the angle drive on the gearbox

I had this problem last summer then coming back from Niagara the speedo died. The right angle drive input shaft had snapped because the speedo cable had stopped when the speedo locked up solid.

Ends up the source of the problem was dried up grease on the odometer gears in the speedometer.

I'd recommend pulling the speedometer out of the dash, lubing the speedometer cable, then taking the guts of the speedometer out and making sure the gears on the odometer parts are not sticking. If they are sticking it is easy to lube them. Just be careful of the needle. In the process of diagnosing my problem I ended up taking it all apart and I got the needle back on a little off, so now the speedometer is 10 MPH high.

Rob

Another cause of erratic speedo can be wear in the brass bearing that the needle's spindle sits in. A very careful strip down and reassembly can aid this but an overhaul with new or donor parts is often required.

Unless you would feel confident rebuilding a clock mechanism I would leave the internals of a speedo to a specialist (there goes the spring!)

Thankyou all for your excellent advice. I slid out the cable, which was oily, and gave it a good coating of grease. Hey presto, perfect steady reading ............................ until...............it stopped altogether. I`ve ordered a new one from Christopher Neil but I`m a bit concerned as the ends don`t seem particularly rounded. I`m hoping the extra grease just caused the end to slip.
Thanks again.
Jim