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Speedo

Discussion in 'Kombi Club' started by dells, Feb 5, 2018.

  1. dells

    dells New Member

    Messages:
    9
    Location:
    Sydney
    My '75 Dormobile's speedo is significantly out of whack with the actual speed that the car is going. I've checked with Boris at Vintage VW at Campsie (Sydney) and he says that the wheels appear to be the correct size so he doesn't see why this could be the case. For example, when I checked the speed just over the border in Victoria at the official speed monitoring apparatus, I was going 92 km/h when the speedo said I was doing 119km/h. Any ideas?
     
  2. Barry

    Barry Well-Known Member

    Messages:
    2,604
    Location:
    Abbotsford NSW
    Speedos always read low - normally about 5% - 10%

    That is a lot though

    I would be guessing it's just a case of old age.

    Double check your tyres yourself with this
    https://tiresize.com/tyre-size-calculator/
    25.4" or 645mm is the diameter you are chasing

    Otherwise
    1 - get a new speedo
    2 - get yours rebuilt / calibrated
     
    KahunaKombi likes this.
  3. dells

    dells New Member

    Messages:
    9
    Location:
    Sydney
    Thanks Barry. Will do.
     
  4. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,304
    Location:
    Melbourne Bend of Islands
    Might just be gunked up internally.
     
  5. David H

    David H Well-Known Member

    Messages:
    3,313
    Location:
    newcastle
    .
    An 'over read' sounds very odd:(.

    To confirm 'indicated 119 & actual 92 kph':confused:?

    Anyway you'll always be safe with the boys in blue;) & think you've got the best Kombi:p.

    Got some spares for sale if needed:).
    Cheers
     
  6. Barry

    Barry Well-Known Member

    Messages:
    2,604
    Location:
    Abbotsford NSW
    Pretty sure there was some rule that manufacturers could not have an under read.
    All cars had to have a minor over read so as they couldnt be responsible for someone speeding when they thought they were not
     
  7. cbus

    cbus Well-Known Member

    Messages:
    10,846
    Location:
    sunshine coast
    Yep. Required in legislation.
    I had speedos read considerably high.
    From memory think one cause may have been worn cable/ speedo connection. ??
    Think other was on a swap so likely different internal gear?
     
  8. David H

    David H Well-Known Member

    Messages:
    3,313
    Location:
    newcastle
    Totally agree. 119/92 is 27 over & close to a 30% over read:rolleyes:.
    Mostly one would consider 'slip' in drive, cable or speedo internals due to wear & thus be an under read.
    Cheers
     
  9. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,304
    Location:
    Melbourne Bend of Islands
    Over-read possibly due to speedo system full of crud. Not so much on VW with drive off front wheel. Gear box driven sometimes get full of oil travelling up the cable.
    Other cause may be wear and something is rubbing in the mechanism.
     
  10. syncro

    syncro Well-Known Member

    Messages:
    8,968
    Location:
    Southern Highlands
    The standard is 5-10%. Most older cars that I have had were 10% and newer ones are 5%.
     
  11. dells

    dells New Member

    Messages:
    9
    Location:
    Sydney
    The over read starts early (eg speedo reads 50, actual speed 41; speedo 60, actual speed 50 etc) so it's always above 20% over. David is right..I'm never over the speed limit but sense that it's nothing much to worry about. The odometer clicks over at 99,999kms so I have no idea how many kms the kombi has done either. Now up to 27,000! I'll take what all have said on board and try to sort out the best solution.
     
  12. Barry

    Barry Well-Known Member

    Messages:
    2,604
    Location:
    Abbotsford NSW
  13. cbus

    cbus Well-Known Member

    Messages:
    10,846
    Location:
    sunshine coast
    Constant linear high sounds like it needs calibrating.
    Remove unit and VERY carefuly lift needle off then reset it at zero and check before firming in place.
    Will be ' how to's' on a search.
    Or Al may say how.:)

    Some spray grease or heavy duty lanolin down cable won't hurt.
    Check condition of ends and hub cap same time.
    Lube speedo as per instructions or Al's advice.
     
  14. chris taylor

    chris taylor Well-Known Member

    Messages:
    1,549
    Location:
    adelaide sth aust
    I have the same situation with my 76,reads 4klm hr faster than im doing ,happy to have it that way. the old ones needle used to bounce so had a s/hand one fitted.
     
    David H likes this.
  15. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,304
    Location:
    Melbourne Bend of Islands
    As above. Speedos were factory calibrated up to 5% max error. Police speedos were more accurate with 2% max. All were calibrated to read high so you would not get booked. Old age may cause more error. Changing rolling diameter with different wheel/tyre combinations on the front will alter reading. I know my speedo reads high so I (try) to stick to speedo reading and don't get a ticket!
     
    chris taylor likes this.
  16. syncro

    syncro Well-Known Member

    Messages:
    8,968
    Location:
    Southern Highlands
    I've never seen a Kombi/Beetle less than 10% when they were new.

    Australian Speedo accuracy standards
    Australian Design Rule 18 sets out the accuracy standards for vehicle speedos.

    From July 1 2006 a new standard began its phase in and by 1 July 2007 all new vehicles had to comply. The new standard requires that:

    • The speedo must not indicate a speed less than the vehicle’s true speed or a speed greater than the vehicle’s true speed by an amount more than 10 percent plus 4 km/h.
    • Odometer accuracy is no longer defined.
    https://www.drive.com.au/motor-news/how-accurate-is-your-speedo-20140716-ztmh4

    They have to make the the speedo read higher in case the owners change to taller tyres etc. eg Changing the tyres on a Caravelle to light truck tyres.
     
    Last edited: Feb 7, 2018
    evan&janine and chris taylor like this.
  17. old grey

    old grey Well-Known Member

    Messages:
    717
    Location:
    newcastle
    My 69 utes speedo is in MPH and 'bounces' a little bit. I likethat im not exactly sure what speed im doing but am sure that the cop that pulls me up for speeding will more than likely just want a look at my vw.
    I love the gear ratios and its quick off the mark as its so light when empty. I know i can drive pretty hard around town (not all the time) and give it a bit on the more open parts of road or coming up to a hill.
    I drive to conditions not the speedo.
    I got a small speeding ticket once in the old grey 20 years ago but have been sweet since. The cop was getting heckled by his partner as he was writing us up for being 8 ks over in a 70 zone. I was coming down off Stockton bridge and believe i was going quicker but knew i was speeding so i took it with a smile.
    Pretty good record i think.
     
    chris taylor likes this.
  18. chris taylor

    chris taylor Well-Known Member

    Messages:
    1,549
    Location:
    adelaide sth aust

    Were you happy at the fact that it could actually go fast enough to get a speeding ticket, wow, it sounds like getting busted for that alone made your day. ;)
     
  19. chris taylor

    chris taylor Well-Known Member

    Messages:
    1,549
    Location:
    adelaide sth aust
    When i changed over from radials to light trucks i thought my speedo reading might have altered a bit and probably has ,but when going through one of those speed checks on the road it reads 4 kph faster than i am actually going , dont know what is was before but happy to leave it as is now .
     
  20. dells

    dells New Member

    Messages:
    9
    Location:
    Sydney
    Thanks to all for the feedback. I'll try to determine the best option and put it on the priority list of 'things to do with the kombi.' Cheers
     

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