Speedo drive

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Liam86223
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Speedo drive

Post by Liam86223 » Sat Dec 12, 2020 3:32 pm

Hi guys I’ve got a 1.8 gt-2 5 speed and when driving it seems to show 5 mph slower than it’s displaying, so I found out it has a white speedo drive and when looking online it’s supposed to have a red one.

I’ve bought a circlip and a red drive but the new drive won’t stay on the end of the cable and it won’t fit with the circlip so I’m stuck.

Any suggestions would be really appreciated.



Kdc169
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Re: Speedo drive

Post by Kdc169 » Sat Dec 12, 2020 5:13 pm

You have to get the circ clip, in the groove first, then push the cog over it.. try a bit of grease.. soak the cog in warmish water to help it pass over the circ clip. Cold days dont help.

Still even with different drive you may find discrepancies in speedo, due to wheel and tyre ratios. See attached.

End of the day if shows 75 and your doing 70 on motorway you keep your licence. 1 of the reasons why 10% +2mph rule was there, due to mechanical measurement, now you just plug in to live OBD and can see speed,done by ECU. Depending on quality of GPS you may also find difficult to check calibration, so i guess rolling road or MOT bay.
speedo.jpg
speedo 1.jpg
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C 20 CCO
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Re: Speedo drive

Post by C 20 CCO » Sat Dec 12, 2020 6:25 pm

Haynes manual shows what needs to be done, if you have one. I swapped my drive gear many moons ago and managed it with no problem.


kind regards,

Dave.

To be old and wise......
You must first be young and stupid!

Previously owned: 1984 1.6 CL in alpine white; 1986 1.6 GT in met light blue over black body kit; 1990 1.8 GT2 in silver.
Currently: 1991 GT2 in Pearl green metallic.

Liam86223
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Re: Speedo drive

Post by Liam86223 » Sat Dec 12, 2020 10:21 pm

Thank you for the advice I’ve got the circlip but when I push it on it doesn’t seem to want to go all the way it has a nipple in the middle of the circlip, unless I’ve bought the wrong one



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Blueshark
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Re: Speedo drive

Post by Blueshark » Sun Dec 13, 2020 1:14 pm




mark1gls
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Re: Speedo drive

Post by mark1gls » Sun Dec 13, 2020 5:49 pm

Most VWs speedo over read by about 5 mph, I’ve had a 2002 vw polo over read as did a 2005 VW Touran, 3 different transporter vans all over read... I guess it’s a bit like VWs claims of fuel economy... just a little out :-D


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GT_II
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Re: Speedo drive

Post by GT_II » Mon Dec 14, 2020 12:32 pm

This is not just a VW thIng. Speedos are allowed to over-read by up to 10%, so most are designed to over-read by around 5% to provide a safety margin. Add in a couple of % for tyre tread wear and you're over-reading by 5 mph at 70 mph.


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RussGLAuto
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Re: Speedo drive

Post by RussGLAuto » Fri Jan 29, 2021 8:02 am

The GL was 8 MPH over reading when I first got it. The tyres were 20 years old. Changed them for new and guess what, now back to VW 'standard' 5 MPH over reading...

Old perished rubber makes a difference...


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