speedo in mk2

[jungleboystu]

i have put a set of clocks in my 1990 1.6 mk2 from a gti with the rev counter in it, and the indicated speed is about 10mph out. ie im doing 30ish and the clock shows 4ish they are 120mph gagues. does anyone have any ideas how i can sort this problem cheers and one last thing how do u upload photos so i can put them on the forum.

[Diamond Hell]

The speedo you've swapped in probably has different gearing in it. What's the number in the middle of the clocks that were in there and those that are in there now? Is it different? Should be something like 1540

[jungleboystu]

ya i hava had a look at both clocks and they both say 1540 on them what does this mean

[Diamond Hell]

Well that means that they should read right.

Bear in mind that you're dealing with 20 year old instrumentation.

At least it's over-reading, rather than under which might mean you get unexpectedly nicked for speeding.

How do you know it's reading out? What have you checked it against?

[Crasher]

Take out the speedo cable from the box (clean around the area first and pull the cable out slowly) and on the end of the cable you will find a pale coloured gear with 16 teeth. Pull this of and replace it with a red one which has 15 teeth, VW part number 171 957 821 B for £3.63 and refit the cable.

[jungleboystu]

i havent actually checked it agianst another car but i can feel it when i drive but it def doesn't feel like wot it is showing i have also niticed with further invetigiating the when im stationary the needle doesn't sit right on the stop and the white clip on the cable the secures to the back of the speado head is broken i broke it removing my old clocks with this have any affect on it

[Crasher]

Fit a new cable when changing the gear and remember to order a circlip.