speedo drive color for 4.11 ratio mk5 diff?

[josht]

hi i fitted a 4.11 ratio diff and high profile tyres to my mk5 i also changed the spedo drive to a blue one but the speedo still reads wayyyy to slow 10mph under at 50 just wondering if there is a better drive to fitt? it has electric speedo and i changed out the white one for the blue one that was a nats cock smaller

[AlanN]

I had a blue one for my 3.89:1 and it only 1 - 2 mph out, Ive kept it just in case I go back to manual. I'm sure green is 4.63 and I think my previous 5.14:1 was a pink-ish colour, but I didn't keep it, so my memory is a little vague.
My current C3 auto has a red one for my 3.89 again a only 2mph out, but that had a green one for a 3.44 granny axle.

[josht]

The speedo was reading a little bit too fast but when i changed the tyres it was reading spot on. I fitted a 4.11 diff and it was reading way too slow so i orderd a blue speedo drive wich was hard to tell the differance in size between the white one and the blue one. They had the same number of teeth is that right?

[AlanN]

I would expect there to be a different amount of teeth or the pitch to be different, I'll try and get a photo of the one I have tomorrow

[josht]

yea thats what i thought

[josht]

Iv counted the teeth on the drive and there are 22 teeth ford say they list 22 and 24 teeth drives. Am i right in thinking the smaller the drive the faster the speedo will read?

[AlanN]

My blue one has 24 teeth

[robbie.cee]

how big are the wheels- not a monster truck now is it?

if only diff thats different, then the output from gearbox stays same max rpm, its the final drive thats changed,
on that logic,, it must mean the speedo drive would need less teeth than before to correct speed. possibly one compatable from a car that used mt75 like some peugeots i believe as well as fords ! fek knows what coulur but id guess 18 or 19 teeth possibly?

[godderidge]

19 teeth yellow if that does not work you can change the worm gear that drives it and there are three to chose from with 5,6 or 7 teeth

[AlanN]

Are you talking about the speedo worm on the main shaft, never heard of a different one listed. You could get get in a right pickle with 6 speedo pinion gears too

[godderidge]

Yes the worm drive on the end of the main shaft. I had a Mk5 with a 4.11 diff and with 235/65/16 tyres and could not get the speedo to read right so had to change the worm drive to the 7 tooth item to make it read right, got it from fords but had to wait 3 weeks for it

[josht]

yea bro there the same size wheels im running dont spoze you have a part number for that gear? is it a easy job to change it?

[godderidge]

Dont have part number but very easy to change

[AlanN]

You have to drop the prop and remove rear seal, unbolt the nut on the end of the shaft, to get to that gear...

[sportscott]

My blue one has 24 teeth

A very old post I know but am having trouble with my speedo, I had the clutch replaced a couple of years ago and it was the worst job ever. Apart from that when I got it back the speedo was over 20 kmh out, and as a result the motor was cutting out at 160 kmh when I was only going less than 140, I disconnected it and drove it a couple of years without a speedo relying on Gps but thought I'd look into it. I must add I changed the gearbox as the bad clutch job put paid to the original and changed the speedo pinion drives, to use the original white one that was in it but it didn't make any difference. Today I bought a new sensor in the hope that I could rectify the problem as in the bad clutch job hadn't put the cable in the right place and it had worn on the propshaft. I read through some old posts and thought I would look into the pinion gears, I replaced the original white one 22 teeth, with a blue one 23 teeth, that came with the replacement gearbox and now only between 15 and 20 kmh out but still not within tolerance. I read Alan, that your blue gear has 24 teeth if I could find one with the same amount of teeth it would slow the speedo yet further and be more accurate, before all these problems the speedo was almost accurate, hard to believe as the EU law states it must read higher up to 10% Has anybody got a blue pinion gear with 24 teeth spare? just read another post from 2009 and it says that the gears are white 22 teeth, blue 23, or brown 24 teeth, I think it's the brown one I need.




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