speedo out

[Bessie the camper]

hi all

im speedois reading about 20kmh out ive checked the back of speedo cable pushed in and the clip is on the wheel end i dont know what else to look for

[kevtherev]

is the tyre the right size?

[Bessie the camper]

what size should it be mate

[kevtherev]

depends on the rim

[Bessie the camper]

all four are 185 14

[kevtherev]

tyres are ok then.
was it 20% at all speeds?... I assume this was a sat nav comparison?

[Bessie the camper]

there or there about mate i had annette follow me this morning on handsfree sat nav was about 3mph out to annette speed

[kevtherev]

sounds about right to me Gareth.
might be worse if you ever chance the shed at 60

[Bessie the camper]

sounds about right to me Gareth.
might be worse if you ever chance the shed at 60

how dare you call it a shed

[kevtherev]

made of wood innit...

[1664]

made of wood innit...

well chipboard really.........

[andydormer]

Hi All,
Sounds like our van has a similar problem with the speedo.
Had hoped removing the big alloys it came with for original size wheels and tyres would fix it.
I've checked the speed given on the GPS to the speed of my wife driving her car infront of the van too - GPS is correct.
The front hub grease cap is in good condition and the cable is clipped in ok. It is the clip on type at the dashboard end of the cable.

From memory, approximately 30mph on Tomtom is 40mph the speedo, 40mph on tomtom is 55ish on the speedo, 55mph on tomtom is almost 70mph on the speedo. Next time we're out I'll ask the wife to write the numbers (mph and kph) down so's I can concentrate on the road

Read somewhere on the forum that the number at the bottom of the speedo (805) sets the gearing ratio... but from what I've read that sounds right for a 1984 2wd caravelle... is this correct? Could the previous owner have bodged the wrong speedo components to the right speedo face and blamed the alloys?

I'm confused how greasing the speedo will stop the exaggerating of the speeds?

[AngeloEvs]

The needle is only a friction fit on the shaft and could move out of calibration over time. Add to the fact that most Speedos seem to read a bit higher on most of the cars I have ever owned.

The speedo (correct one) was out on my van too - same % margin of error (compared to Tom Tom) over a range of speeds - I removed the Speedo - rotated the needle to 65 MPH, gripped the shaft with a small set of pointed nose pliers and gently applied pressure to the needle and rotated it to where it should have been - 55MPH. Been fine ever since.

[ghost123uk]

I removed the Speedo - rotated the needle to 65 MPH, gripped the shaft with a small set of pointed nose pliers and gently applied pressure to the needle and rotated it to where it should have been - 55MPH. Been fine ever since.

That is common practice on old British (Lucas) motorbike speedos