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Gearbox clutch judder

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  • Gearbox clutch judder

    Hi I have a corsa 1.2 16v with bad clutch judder and seems like gearbox noise as well any pointers would be grateful to sorting the problems thank you

  • #2
    Hi welcome to the forum

    Sorry for the delay. This is quite a difficult one to try and diagnose on line. There are several possibilities,and getting it wrong might cost you significant money. It may be the clutch is simply worn out and needs replacement. A clutch that is worn out might judder ,or could be noisy. It can also make selecting or changing gears difficult, that might be misinterpreted as problems or noises from the gear box when in fact the gearbox is fine.
    Or the difficulties might be due to leaking clutch hydraulics, either the master cylinder or the slave cylinder. The master cylinder is near the brake pedal and might be fixable with less work than the slave cylinder, which is basically involves almost as much work as replacing the whole clutch.. Indeed its false economy just to replace the slave cylinder. Its better to replace the whole clutch at the same time, unless its obviously almost new. Equally its false economy to fit a new clutch without also replacing the slave cylinder , or without also rectifying any leaking oil seal that might be evident. that might have contaminated the clutch (and any replacement if not rectified) And by the same token , you dont really want to replace the clutch, only to find the gearbox was indeed faulty and the whole lot has to come out again. Or replace the gearbox without also taking the opportunity of fitting a new clutch and slave cylinder while the gearbox is out.

    Although less likely in your case because of the judder and noise,others may find their difficulty in selecting gear for instance is due to a worn and sloppy gear change linkage,rather than the clutch.This linkage is external to the gearbox, and fairly easy to replace as the gearbox itself does not have to be disturbed.

    As you can see the potential costs could be high if its misdiagnosed. Ideally try and find a trustworthy garage, where an experienced mechanic may be able to diagnose what needs doing. If he warns you of finding possible further problems or advises fitting a new clutch rather than just parts etc, , he may be giving good advice, not trying to scam you into extra work. .Its better to know the worst case scenario up front, with some idea of the likely costs should extra work be necessary, than just to go for the cheapest 'clutch job'quote, who might only 'discover' extra work when the car is already dismantled, and you are at a severe disadvantage regarding getting a better quote..

    The fact an initial quote makes no mention of potential extras doesnt necessarily mean the garage are dubious. Some customers like to keep it simple. But these are the customers most likely to be ripped off by the less scrupulous. If they dont offer details up front its a good idea to ask them , what parts they intend to fit for that price,what brand of clutch they might use , potential costs of problems that might be found. They are less likely to try and rip you off or take short cuts if specific details of the work have been agreed in advance.

    You could check the clutch fluid level has not dropped. although this will just conform that work will be required. Topping up is not a cure. Equally you can check on line for ways of diagnosing a worn or slipping clutch. But again this may only help conform work is required, It doesnt give the all clear.

    I dont know how how likely it is to be a cause but you could also check that an engine or gearbox mount is broken, or damaged (they contain rubber bushes that might be perished. ) A faulty mount can allow the engine and gearbox to move in the engine bay,. This movement may not be evident on an engine that is just idling, but it may twist under torque loading such as when accelerating or descelerating. One indication of sloppy engine mounts is if the gear lever moves position under these conditions.. Diagnosis of sloppy engine mounts in the garage might involve getting under the car, or testing for excessive movement with a lever. Never climb under a car thats only supported on a jack.

    If your gear lever moves in this way or you discover a mount that is obviously broken or badly perished it might be worth discussing with a trusted mechanic how best to proceed. Just Doing the mounts might be a fairly low cost cure, but if it doesnt completely solve the problem and you then need to replace the clutch there may be some duplication of labour costs.

    Let us know how you get on.
    Last edited by Bugman; 31-07-2020, 06:39 AM.


    • #3
      Hi it turns out to be a very bad gearbox fail the oil was like a silver colour. Gearbox and clutch replaced as good as new now. Are the gearbox on a corsa bad as this is the second one it's had now?


      • #4
        Thanks for reporting bad . A lot don't. I've specializes working on Corsa's the last 20 years , and have only changed 2 in that time . I think it's a lot to do how it's been driven and the wheel sizes people put on the corsa ,
        Last edited by Restorer; 01-08-2020, 12:06 PM.


        • #5
          Standard 17"wheels and I am 49 previous owners where young boy racers


          • #6
            Hi, what model and year is your Corsa. 17" wheels were only standard on the SRI models with updated gearbox and larger diameter driveshafts.


            • #7
              49 . ! Eligible for reminiscing . As Restorer (the youngest member of the reminiscing old codger squad) says the corsa gearbox is not known to be particularly fragile. Although oversize wheels and tyres can increase the strain.

              The silver oil may be significant. Lithiam engine oil is silver when new . There may be lithiam based gear oils. Gear oil is available as GL4 or GL5 specification. GL5 has additives that have better extreme pressure shear performance,than GL4 but these additives can have an adverse affect on bronze alloys found in some older gearboxes (eg synchromesh parts) But GL5 is often marketed as the latest, superior, specification for high performance ,when in fact the GL4 might suit the gearbox better. .

              More likely I think is the silver is the result of bronze alloy synchromesh parts degrading. either from the wrong spec oil , or physical abuse by 'boy racers' or a driver who has got into a bad habit that puts extra strain on the gearbox or clutch .(eg those who sit at traffic lights with the car in gear and their foot on the clutch instead of going into neutral. -dangerous, and wears out the clutch release bearing)

              E by gum when I were a lad synchromesh was weak, or even non existent on some lower gears (many cars had no synchromesh from 2nd into 1st) 'enthusiastic' drivers learned to double declutch to down change at higher speeds with minimal strain on the engine,gearbox or drive train. Few drivers these days use the technique, even on the racetrack. The greater the mismatch between engine and gearbox the driver expects the synchromesh to ,erm , synchronise the greater the wear and tear, both on synchromesh parts that have to slow down rotating parts and the increased torsional loading differences in the gears themselves.

              Gears . Hah. We had to carve the wooden gear pegs with our teeth and hammer them into the windmill gears with a rock. And then eat the wood shavings for supper. Those of us that had teeth.


              • #8
                Have you been drinking mate


                • #9
                  Sunday evening was maybe not a good time . Better a little wine with your dinner than a little whine in your gearbox.

                  But I see what you mean. I had completely forgotten the bit about catching a sheep, shearing it with a piece of flint and using the Lanolin in the fleece to lubricate the wooden gears.

                  Fortunately Corsa1 's problem is already sorted.