Speed issue (reading wrong)

[MattRocco]

Hi guys having a issue with my speedo, basically I'm going a lot slower then what my speedo reads. It's anywhere between 10-20 mph out... I have found out by having altercations with tailgating drivers on more then one occasion now. Such as being told I'm doing 40 in a 60.

Only thing I've done since I have had it is put some 15" BBS rd wheels on 185/50/15 tyres.

Now I think bigger wheels will affect the mph but surely not by that much?

Time for new clocks?

Regards
Matt

[Little_bro]

Have you tried using a sat nav. As set to show your speed. That way you will know how accurate your speedo is

http://www.tyresizecalculator.com/tyre- ... calculator

[MattRocco]

No I haven't tried nav as my polo had it build in headunit so don't actually have a portable one. I did follow him in polo when he drove it and he was about 10mph short in 40/30 speed zones but I don't know the exact figure

[mr.brown]

Probably not the tyres as there's only a couple of per cent difference in the overall size. There are plenty of free smartphone apps that can tell you your speed - or even a free sat nav app like Waze will do it.

Was it OK before you changed the wheels?
Have you had the speedo cable replaced? Have you checked that it's seated correctly into the dash clocks?
Any gearbox work done? It could be that the plastic drive gear on the cable is the wrong one.

[MattRocco]

I wouldn't know as I've not long put it in the road so these are my first few days actually driving it. It had a clutch done so will look into the cable side of it, thanks for the advice

[Nate]

if i've worked it out right, that tyre size should have you going 2mph slower than indicated (bearing in mind they almost always over-read a bit anyway.

i'd be surprised if you were doing 40 but thought you were doing 60. there is a big difference in the feel of the 2 speeds. i'd compare it to a splatnav or smartphone speedo app and see what the actual difference is

[mark1gls]

Does it look like someone has messed about with the instruments, eg coloured dials?
They may of took the needle of the speedo and not put it back on right.
As Nate said they do seem to over read straight out from the factory.

[MattRocco]

Cheers guys, well the miles don't actually turn over at all just stuck on 150k so possible that someone's previously tried to fix this and moved it all out of sync.

Probably time for some new clocks, although seem to be few and far between other then the ebay ones for £150 unless that's the going rate for them?

If I was to strip the clocks myself is there a set place for the needle to sit, and does the spindle bit it sits on need any amount of tension first, I.e do I need to remove the needle then turn the bit the needle goes on or just remove the needle and set it back a bit?

[DT1]

Cheers guys, well the miles don't actually turn over at all just stuck on 150k so possible that someone's previously tried to fix this and moved it all out of sync.

Google VW odometer fix.

Probably time for some new clocks, although seem to be few and far between other then the ebay ones for £150 unless that's the going rate for them?

Put up a thread in parts wanted. The e-bay prices are inflated.

If I was to strip the clocks myself is there a set place for the needle to sit, and does the spindle bit it sits on need any amount of tension first, I.e do I need to remove the needle then turn the bit the needle goes on or just remove the needle and set it back a bit?

How to reset the needle but if the odometer is bust it's only worth doing so that you have the right speed until you can get another speedo.

[mark1gls]

If the miles are not turning over there is one of the cogs slipping, a common problem and a straight forward fix but can be fiddly.
It seems from the post above there is a mark on the speedo to set the needle so check it's at the right place.

I had to adjust mine on the Mk1 after mine stopped adding miles but the speedo worked.

viewtopic.php?f=16&t=15877

viewtopic.php?f=10&t=17598

The cogs that slip could be the white one here, which is the easy one to fix I used a little super glue to hold it on


Or it could be the harder one to fix like mine the metal (your's might be plastic on a Mk2) as you have to remove the metal bar which hold all the numbered cogs on do the very carefully and make a note of the mileage as I pushed to hard and all the numbered cogs fell on the floor so had to reline all the cogs and fixings to get the mileage right.

[Little_bro]

I have a spare odometer I could sell you with postage for £10

[MattRocco]

Thanks for the advice guys and the information, will take the clocks out this weekend and give it a go carefully. Appreciate all the help

I've PM'ed you littlebro

[MattRocco]

I took car out today with a GPS app on my phone and the car appears to be 10mph under what the speedo reads. I stripped it down (well tried) moved the needle back to where it says on the post above, unfortunately I'm not as delicate as I thought as I broke the needle (taped it back together) tried to fix the mileage issue but once I got to it they all span freely and when turning it the mileage goes up, so glued the bite it said. Built it all back up and tested. I have somehow lost a back cover so you can see the board and still according to my gps app I'm 5mph out and mileage stopped again after moving up 2 miles... I am disspointed in myself but hey ho shit happens! New clocks time I think :(

[mark1gls]

Sorry to hear it did not go well but 5mph sounds about right, my car is about 5mph out on the speedo and has always been like it, even with my wifes honda civic with an electronic speedo drive it's 4-5 mph out. I guess it's so you don't get a speeding ticket

The tape holding the needle may not help as it's adding extra weight to it.
Have you tried resetting the mileage trip to see if that help? I could do that with mine and it would work as far as 0.9 mile or 1.9 miles etc then stop counting or if I was luckly 9.9 miles,in the end it was the harder to get to cog slipping.

[MattRocco]

5mph isn't too bad so can live with it! No haven't tried that but will give it a go on the way to work today