‘Clunk’ sound when taking up drive

Discussion in 'Mech Tech' started by Zoedanbus, Oct 14, 2019.

  1. Hi there, had this for quite a few years and thought I’d see if anyone had any thoughts.

    When I take up drive and release the clutch we get a ‘clunk’ sound. This only seems to happen when changing from reverse to first gear (and vice-versa) and then starting to drive as the clutch is released.

    Hope that makes sense. It’s a single ‘clunk’ sound each time. Clutch or release bearing? Or something more sinister in the gear box?

    It’s a clean single sound that’s is metallic in nature.

    Cheers again
     
  2. Faust

    Faust Supporter

    How quick do you release your pedal when in 1st ? if the pedal is not adjusted correctly could well be the problem .
     
  3. nicktuft

    nicktuft Supporter

    Sounds like worn mountings somewhere.
    Put it in gear and try rocking it to see where the noise is coming from.
     
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  4. Ah, careful release like during normal driving and when setting off. Nothing aggressive.

    Ah, the mounts is a good point, it does have that heavy sound like a large bit of metal hitting something. Will check these out too. Great! Thank you.
     
  5. Might it be the slack getting taken up in the Ring and Pinion, or the Diff? Tho' the mount is most plausible.
     
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  6. Check your CV Joints and your wheel bolts
     
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  7. ^this
     
  8. Don't CV joints tend to click, make a higher pitched sound? Not saying it isn't the CV, just wondering.
     
  9. Yeah I think they’re solid, but will check on all this when I have a moment. Thanks all!
     
  10. It is quite a deep clunk
     
  11. Could be slack in the gearbox, check everything else first, of course. But if the output part of box is a bit worn, you might find the slack needs to be taken up when changing direction.
     
    Last edited: Oct 16, 2019
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  12. matty

    matty Supporter

    Worth also checking the mounts especially the rubber block under the pickle fork at the front of the gearbox
     
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  13. Sorry I meant to check the CV Bolts. I have seen so many with missing or snapped bolts.

    To check mounting I would get a friend to bring the clutch to the bite with the brakes on and see if the engine clunks on it's mounts.
     
  14. mikedjames

    mikedjames Supporter

    Or jack it up one side, put it in gear and try to turn the wheel that is in the air in either direction.
    If its CV joints you will see bits turn relative to each other that shouldnt.

    If its in the gearbox, the whole driveshaft attached to the wheel will turn and then stop.

    If its a front gearbox mounting you would expect to see missing bits and shiny metal at the front where it is hitting..

    The two prongs at the front mounting should be clamped by a metal block with two grooves in it for the prongs and two big bolts.
     
  15. Update on this, finally had a chance to sort. Clunking was the result of worn CV joints. Thanks for your input everyone. ;)
     
  16. Day

    Day

    Can I ask.... What parts were worn...
    I may need to do same.
     
  17. The cv joints themselves were original. Well repacked with grease 20 years ago, but the ball bearings and cv joint bearing faces were noticeably wearing on a couple of joints. Beyond repair. Installed all new Lobro joints.
     
    snotty likes this.
  18. It was quite a heavy clunk when taking up drive when changing direction (reverse to forward and vice-versa). Had clicking when turning camper and worn side became unloaded with the roll of the vehicle body. Taking up drive when going through gears now actually feels more positive too which is nice.
     
  19. i made a point of reinstalling the shafts the same as they came out as I'm sure it would stress (twist) them when under load and wouldn't like the direction to change after all these years.
     
  20. mikedjames

    mikedjames Supporter

    I think you are OK on drive shaft end swaps because each clunk corresponds to a massive torque reversal.
    One recommended way of prolonging CV joints life is in fact to swap the driveshafts round to even the wear..

    Its the rear suspension torsion bars that are wrought iron with a built in twist in the grain which can open out and crack like string untwisting if you swap them. They are meant to be marked L and R to remind you which side to fit them.
     
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