Speedo being odd...

[jon]

Bit of a strange one this....
The Speedo on my TE51 corolla has started over reading by about 20mph, but only (it seems!) after the engine has got up to temperature, and it goes back into 30/40mph after a fair run at 60/70mph. Sometimes it goes back to normal if the engine is turned off and started again, sometimes not.
Any ideas??
jon

[jon]

anyone...

[harvey]

Strange one Jon, never came across this before in 25 years of toyota ownership! As the speedo is a mechanical setup,and the way speedos are calibrated I have been told, is by the altering distance the magnets are away from the rotating coil which is driven by the cable. Could anything be loose within the speedo head itself?
I think I have an old TE51 speedo head which you can have if I can find it that is,which is easier said than done in my garage!

Hopefully someone can answer your question

[airfireman1]

I had this problem with my old TA22, it used to read about 20kph fast. what i did to fix the problem was remove the speedo and take the needle and face off. You will find a small brass nut that can be adjusted to add extra tension to the needle shaft. I lubricated all the shaft and bush it runs in then adjusted the nut up slightly. i then connnected the speedo without reinstalling it in the guage cluster and did several test drives with a pace car and kept adjusting the tension on the needle shaft until it matched the pace car speed on the face. it only took a few goes and I have had no more problems..I think that over time there is some wear or loss of tension in that asembly and it causes the needle to move too freely.
If you can try a different speedo first it would be good. This was a last resort to ry and get some sense from a 35year old speedo.
Cheers Dave

[jon]

Cheers both! If you could find your spare Harvey that'd be great, how much would you want for it?
jon