In-accurate speedo

[pyebibby]

Im sure that i'm all out! doing 50 on the speedo and i recon i'm actually doing 60... its all ratio's and its out. What can be done to one test the speed and two fix it.

[ASL642]

Borrow a Satnav and get someone in the passenger seat to compare it whilst you're driving.. Don't be tempted to take your eyes off the road to check!

[bmcecosse]

Follow some trucks on the motorway - they will be doing 56 mph.......

[mike.perry]

What diff have you got in the car and what is the TPM (4 figure number) on the dial?

[pyebibby]

will reply on the 4 digit number when i go and wake her up next, and as for the motor way... i dont know if i want to get up to 56 mph!

[phurn]

and why not! i regularly take mine up past 65 and apart from the gearbox sounding like its about to explode theres nothing to worry bout!

[chrisryder]

you'll know when you're doing 88 when you end up leaving two lines of fire behind you, and end up in the 1950's

the tip with the lorries is a good'un. or follow a friend who will travel at a pre-arranged speed. or find a sign that flashes up your speed, ideally one that tells you exactly how fast you're going (although i did go past a broken one that said i was doing 7mph...)

[pyebibby]

SN4477/OOA 1504 does that mean anything to you? i like a lovely fuel steady 40mph

[bmcecosse]

That's the speedo for a 4.55 final drive. Is that what your car has?

[mike.perry]

If your car still has the 948 engine, box and 4.55 diff then that is the correct speedo. If it has been changed to a 1098 with 4.22 diff then you need a 1408 speedo

[pyebibby]

aaargh! yes, shes got a 1098cc engine in her and shes originally 998cc... ok, is that change just a change on the dashboard or alot more?

[chrisryder]

depends if when the 1098 was fitted if they changed the diff too!

[pyebibby]

i'll ask my old man!

[bmcecosse]

It's a simple speedo swap - start looking for a 1408 tpm - IF the car has the 4.22 final drive fitted. BUT - it's only a 6.6% inaccuracy and quite frankly when new the speedos were often ~ 8% inaccurate anyway - see any of the period roadtests!

[mike.perry]

1098 engine, that's good for 70mph. 40mph gives Morris Minors a bad reputation. They sound frantic at speed because they do not have the sound proofing of modern cars.

[phurn]

Mine sounds just as frantic at 40 as it does at 70! More gearbox woes than engine, but there's no excuse to keep it at 40! I do more than that down windy country lanes.

[chrisryder]

got mine up to IGN when i first got it

i'm far more sensible now!

i'm aware of a 10% inaccuracy of my speedo, and i just go past speedcameras accordingly. it means i can happily go past a 40mph camera at an indicated 44, even after 3 years of it, i have to think twice!

if it were me pyebibby, just find out how innaccurate it is with the help of a friend or a satnav, and calibrate your mind accordingly!

[pyebibby]

yh sounds like the cheapest option! and my speedo is in such good condition (suppose they all do under the glass?!) haha

[mike.perry]

Th speedo would be in good condition if the 40 - 90 mph part of the dial has never been used

[pyebibby]

that is VERY TRUE!