Crazy speedo

Anything to do with the electrics of the car.

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Jon M
Posts: 66
Joined: Thu Dec 16, 2004 9:35 am

Crazy speedo

Post by Jon M »

Hi,

My speedo has been playing up occasionally, bizarrely only when I'm travelling east on the M4! It just seems to dance around between 80 and 110 MPH, not sure what speed I'm actually doing but it's about 4k RPM in top. I have a '91 N/A so presumably the cable-driven speedo. Anybody got any ideas? Cheers,

Jon
nutter

Re: Crazy speedo

Post by nutter »

a mate of mine had this problem, the speedo would work for the first 20 mins then just die. He tracked it to the gearbox. he replaced the speedo drive but that didn't do anything. Apparently there is a nylone gear inside the box that strips sometimes :shock:. He just went to halfords and bought a bike speedo and glued the sensor on to the back of his front wheel :lol:
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Lauren
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Joined: Mon Dec 13, 2004 5:37 pm
Location: Greater Manchester
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Re: Crazy speedo

Post by Lauren »

Yep, this happenned to Mark's SC. Was the gearbox drive going. You can either replace the gearbox speedo drive or like nutter says, go the option of the bike speedo route.
Jon M
Posts: 66
Joined: Thu Dec 16, 2004 9:35 am

Re: Crazy speedo

Post by Jon M »

OK, does anybody know how hard it is to replace the drive unit? Also what I could expect to pay for one? Or perhaps I should just treat myself to a fancy GPS install.... :roll:
nutter

Re: Crazy speedo

Post by nutter »

well if it's just the drive unit and not the gears inside the box then it quite easy. the drive is held on with a 10mm bolt. although you may need to remove the rear engine mount to get acces to it. Thats just three bolts though.
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