Section : Gearbox

VIT MKI Overdrive Engage/Disengage

Posted By : Lee Codrington, 10-May-2004, 12:33pm

• VIT MKI Overdrive Engage/Disengage

  Posted By : James Carruthers, 10-May-2004, 12:56pm

  Lee,
  
  
  Canley have some good information about common overdrive misfunctions...
  
  http://www.canleyclassics.com/infodatabase.asp?top...
  
  
  
  
  James
  

  • VIT MKI Overdrive Engage/Disengage

    Posted By : Lee Codrington, 10-May-2004, 04:56pm

    Cheers James,
    I've now bookmarked the webpage.
    Lee

    • VIT MKI Overdrive Engage/Disengage

      Posted By : Huw Harrison, 10-May-2004, 05:29pm

      Hi Lee
      
      I had something very similar happen to me a few years ago on a Herald I had put an overdrive box into, it was the selector bolt not moving far enough which is quite easy to access by removing the tunnel and then removing the 4 screws over the inspection plate. If i tried to click into overdrive off the column switch it would work intermitently but when i reached down and moved the selctor bolt manually, hey presto Overdrive... A couple of turns on the nut at the end and problem solved...
      
      Hope this helps
      
      Huw

• VIT MKI Overdrive Engage/Disengage

  Posted By : William Davies, 10-May-2004, 01:28pm

  Hi Lee,
  Do you have the original column mounted switch or the troublesome gearknob switch from a later car? Common failure with the latter is damage to the switch wires where they pass into the gearlever,
  Cheers,
  Bill.
  

  • VIT MKI Overdrive Engage/Disengage

    Posted By : Lee Codrington, 10-May-2004, 02:09pm

    Hi Bill
    I forgot to mention my switch is column mounted....
    Best
    Lee
    

  • VIT MKI Overdrive Engage/Disengage

    Posted By : Jeremy Derbyshire, 04-Jul-2004, 11:07am

    Ive just started rebuilding a Mark 1, was the overdrive an optional extra?
    
    Mine ceratinly does not have one. Can you reccommend a gearbox specialist that I can send my gearbox to to be refurbished - the selectors and gate are definetlye in need of attention?

    • VIT MKI Overdrive Engage/Disengage

      Posted By : David Rumens, 04-Jul-2004, 09:01pm

      Yes the overdrive was an extra. Have a look in the Courier for a specialist e.g. - Canley Classics, T.D. Fitchett, Rimmers Bros, etc.
      

• VIT MKI Overdrive Engage/Disengage

  Posted By : Laurence Wood, 30-Jun-2004, 03:58pm

  I too have the column mounted OD switch stalk and it is a bit dodgy - if I knock it when turning the OD disengages suggesting yours may also be an electrical switch issue so hopefully more easily fixed !

  • VIT MKI Overdrive Engage/Disengage

    Posted By : Spencer Allen-Scholey, 18-Jul-2007, 09:41am

    My Mark 2 overdrive has stopped working suddenly and I'm hoping its the column mounted switch. I also want to check out the overdrive relay, but I can't find it anywhere! I have a great picture of it in my Autopress manual but no clue as to where it is mounted! Any help would be appreciated!

    • VIT MKI Overdrive Engage/Disengage

      Posted By : Gary Flinn, 18-Jul-2007, 11:22am

      It should be mounted to the right of the Battery/Fusebox on the Passenger side of the front bulkhead, thats the standard position when factory fitted.
      
      Regards
      
      Gary

      • VIT MKI Overdrive Engage/Disengage

        Posted By : Spencer Allen-Scholey, 18-Jul-2007, 02:12pm

        Nothing there but fuses. I've had a good look under the dash, anyone got any other suggestions? If overdrive was added at some point as an afterthought by a previous owner, I wonder if there is a common place to mount the relay?

        • VIT MKI Overdrive Engage/Disengage

          Posted By : Gary Flinn, 18-Jul-2007, 03:27pm

          It sounds like the Overdrive was fitted by a former owner.
          
          You need to check out the wiring really to make sure its been done to a reasonable standard? you need to check the following:-
          
          1. The wiring is connected via a fused & ignition controlled circuit.
          
          2. If its a 'D' Type Overdrive that there is a relay somewhere controlling the feed cable to the solenoid (Original fitment was 'D' type however if a 'J' type is fitted you don't need a relay because it doesn't draw as much current on initial engagement).
          
          3. That the inhibitor switch is wired into the relay correctly to ensure the Overdrive only works in 3rd/4th gears and the Column switch is working correctly.
          
          4. That any wiring is routed and secured correctly to ensure it doesn't touch anything hot or sharp!
          
          5. There is sufficent Oil in the Gearbox (a low level can cause it not to work).
          
          6. That the operating Arm if a 'D' type is correctly adjused again you need a Workshop manual
          
          You need a wiring diagram ideally out of a workshop or Haynes manual and a decent Multi-meter.
          
          If you don't feel confident get an Auto Electrician or a competant friend to help.
          
          I had an intermittent problem with the Overdrive on my car, it turned out to be a duff inhibitor switch, I changed it for a new one and problem solved.
          
          Nine times out of Ten its an Electrical problem with faulty Overdrives.
          
          Hope this helps.
          
          Regards
          
          Gary

          • VIT MKI Overdrive Engage/Disengage

            Posted By : Spencer Allen-Scholey, 19-Jul-2007, 10:13pm

            Thanks for the help. After pulling up the carpet and the gearbox bell-housing I discovered it is a J type overdrive. Continuity checks on the cables and switches were fine but there was no voltage supply to the solenoid. Thats when I discovered the blown fuse in the supply line hidden under the dashboard! Still, I'd rather a 30p fuse than a £87 solenoid - and a lot easier to change too! Cheers!