[Sunbeam Talbot Email List] overdrive

[Mal Clark]

Hi Martin,the overdrive works by means of oil pressure,that is produce by the oil pump in the overdrive,when you operate the overdrive switch it allows this oil pressure to activate two hydrolic pistons that push against two plates that are connected to the cone clutch the piston pressure overcomes a series of return springs,to push the cone clutch to it overdrive position,When the switch is returned to the off position the pressure is released and the return springs pull the clutch back from the overdrive position. if its not disengaging,either the pressure is not being released, or the pistons are stuck, I cant imagine a broken spring as there are so many that work the clutch. You will know when removed.Mal Clark.
  ----- Original Message ----- 
  From: martin clarke 
  To: staowners at sunbeamtalbot.info 
  Sent: Friday, June 25, 2010 11:25 AM
  Subject: [Sunbeam Talbot Email List] overdrive


  Dear Members,
            Has anyone been through the overdrive stuck in overdrive problem. The handbook says that serious damage occurs if the car is reversed while stuck in overdrive. My MKIII saloon has just clocked 2,980 km (approx 1800 miles) in a return trip to Mount Gambier, just across the border in South Australia for the National rally. It was a good roll up, and an enthusiastic atmosphere, with Mal Clarke's handywork impressing all and sundry. Roland Thompson covered approximately 1500km more than I did, in bringing his Fine alpine, and his MKIII drophead from Queensland. 
            Needless to say the overdrive first became intermittent, and then finally decided to lock in about 1,200km from home. A quick crawl under revealed that something (probably broken spring) was preventing the lever from dropping to the off position. Attempts to move it manually failed. Naturally the only choice was to drive home, and inevitably an occasion arose where I could not avoid reversing.
            Fortunately I have a serviceable unit to put in, but I would be grateful if anyone can forewarn me of what I can expect to find when I pull the damaged unit apart.
  Regards,
  Martin Clarke
  Blue Mountains
  Australia


------------------------------------------------------------------------------


  _______________________________________________
  Staowners mailing list
  Staowners at sunbeamtalbot.info
  http://sunbeamtalbot.info/mailman/listinfo/staowners_sunbeamtalbot.info
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sunbeamtalbot.info/pipermail/staowners_sunbeamtalbot.info/attachments/20100625/30bd6559/attachment.html>