Inaccurate speedo

[ianders]

Hi guys.

Wondered if this is fixable or just one of those things with having a T25.

Speedo reads slightly on the high side e.g. 35 on the speedo is 30 in real terms.

Between 50-60mph on speedo I can only describe the needle as very bouncy making it impossible to determine speed.

I would guess that at the higher speeds (around 65 on speedo) it's around 60 (a lot of cars seem happy to sit behind me on motorways and aren't desperately moving out to overtake) so possibly 5mph over on the entire range?

Any ideas what this could be?

Tyres are 185/80R14

[California Dreamin]

Factory standard +10%

Pretty much the normal for old fashioned mechanically driven speedo heads.
This has something to do tyre diameter changing from NEW to OLD and having to have a safe margin.

Baring in mind that back in the 80's there wasn't such thing as 'SatNav' and know one was the wiser. It is only down to the fact that most of us own a device that can accurately read speed, that we have become aware of this fact.

Having said all of this ^^^^ it is possible to remove & refit the needle (idea thanks to Andy at CamperShack)
Once your speedo head is removed. Remove the circlip/grease cap on the N/S/F wheel that drives the speedo cable....as your drill will spin at a constant speed (get the idea), attach the drill, press to full speed....note the MPH...remove and refit the needle minus say 10%..never done it myself but there is no reason it wouldn't work.



Martin

[ianders]

Cheers for that. Some useful info there!

[CovKid]

Or just go up on wheel size, and be in the more competitive and cheaper 15" tyre market and the speedo reads just about bang on.