Gear change difficulty

Discussion in 'Mech Tech' started by seanlithman, Feb 21, 2021 at 6:24 PM.

  1. My van just started having difficulty selecting 1 gear from neutral when the engine is running
    sometimes it won’t go into any gear at all from neutral and is not happy changing down from 3rd to 2nd it needs a good push to get it in.
    I’ve had a cps stick fitted for around 4 years and it’s always been a good positive shift up till now.
    It shifts fine when the engine is not running so I’m thinking it’s the clutch but the clutch hasn’t done a lot of miles and the gears are not crunching. I’ve tried tightening the cable by putting a few turns on the wing nut but it hasn’t made much difference.
    I did notice the Bowden tube is not really got much of a curve in it and I think the last section of the metal conduit may be broken free off the large fat tube that houses the torsion bar I measures the Bowden tube and it’s correct length 350mm
    Any ideas folks
    Could it be the metal cable conduit is too short but it’s been like that for at least 4 years or might it be something to do with the gear shift linkage ?
     
  2. Think? May? It it has, there's your answer.
     
    Lasty, 77 Westy and snotty like this.
  3. Hi Zed is it easy to a quite a new metal conduit and is it easy to replace
    What length should it be it looks like is simple 10mm steel tube ?
     
  4. If it's come adrift just tack it back in place. The length therefore shape of the bowden tube (too straight) can make letting the clutch out grabby but shouldn't effect gear selection unless the conduit end/conduit is flapping about. If the conduit is loose, the bowden tube will push it away from it's position and straighten.

    If the conduit has not come adrift you can cause the S bend by stacking M12 washers (could be M14) on the top end before locating it in it's bracket. Mine is like that. Doing that should also put the adjusting wing nut in the right place on the thread.

    It's not easy to replace all the conduit but it's easy to repair the last few inches with a new piece and a sleeve. I don't remember sizes.
     
    monkeyvanwestybike and snotty like this.
  5. ^this. If the conduit is flapping around, the clutch cable has nothing to “work” against, so operation will be iffy. If that is the problem, of course.
     
  6. The other thing to check is the bolt in the gearbox nose coupler. These come loose and make gear changes harder. Mine undid once in a patch of mud at Volksworld on the grass outside. I could just squeeze my arm under the bus..

    Then also the little donut in the gearbox nose cone can cause extreme slop.

    And a worn out aftermarket shifter- my EMPI has a strip of metal welded one side of the gate under the stick where it wore wider.

    The loop in the Bowden cable with both ends fixed lets the clutch mechanism "find" the biting point by the spring of the Bowden outer "giving" and shortening until the spring coils of the outer bind, just as the clutch lever has enough pressure to start moving.
    A bowden cable outer is a spring in a plastic conduit, not a solid tube.

    If the forward end is not fixed to the tube the clutch will need a lot more movement to release, and be very juddery, as the small distance of the final release movement will all come at once from the clutch pedal rather than being extended by the give in the Bowden tube.
     
  7. Thank you guys for your good advice
    I will have a good look at all the suggestions the cable metal pipe is not flapping around but I think it might be a bit short and is possibly a bit of tube that was put on by a previous owner although I have had the bus for 12 years I’ve not really looked at it bc the gear change always worked well. The old adage of if it works ok leave it alone
    My main worry was that it might be something wrong with the gear box but I assume there would be a terrible crunching noise if the box was at fault it’s more that it is very stubborn going into 1st from neutral when the engine is running.
     
  8. Do the easy stuff first, starting with the clutch. If the clutch isn't disengaging fully (input shaft still turning with pedal down), the gearbox will fight you.
     
  9. What’s the best way to see if that’s happening plz
     
  10. If your cable conduit’s in good shape, adjust the cable to give about 1/2” of free/loose movement at the pedal. About all you can do. A good shove on the pedal should fully disengage the clutch.
     
  11. If the lever on the side of the gearbox is moving, as the pedal is pushed then the clutch should at least release.
    However welds can break inside on a repairable part.

    On my bus if I listen carefully, theres a change in noises from the clutch if I press the clutch pedal with the engine idling. Its some springs in the clutch and other things moving differently without the pressure of the big clutch spring holding the plates together.

    More likely is a loose screw on the gearbox coupler leading to a very floppy gearstick.. if you cannot hear it clicking into gear with the engine stopped and the lever is easy to move take a look at the front of the gearbox just in front of the suspension tube - the bolt in the coupler might be loose or the rubber/plastic blocks in the coupler are missing. Take a picture.

    The other thing to check is that if chock one rear wheel, with the engine stopped, release handbrake and jack up the other wheel, move gear lever into a gear, you should be able to turn the raised wheel by hand only when the clutch pedal is down.
     
  12. Thanks Mike I will give theses a go
     
  13. urther strange behaviour re gears
    So I replaced the Bowden tube with one I found that was 2cm longer
    Put the van on axial stands with the wheels off the ground started the engine and put it in gear it went into 1st relatively easily and through the gears
    Ok I thought
    then I looked at the rear wheels and the near side wheel was turning fine but the drivers side wasn’t moving until I got to 3500 rpm
    Then when I put it in neutral the near side kept moving but I could stop it by hand though as soon as I let go it started spinning
    I thought maybe the brakes are catching on the drivers side but it’s fine to turn the wheel by hand
    Any ideas what’s going on ?
     
  14. Not a very reliable test ;). With the wheels off the ground, they will turn in neutral (oil drag in the box?) Should stop if you grab one. In gear, try caaaarefully stopping the turning one. The diff should make the other one turn. Maybe.
     
  15. 3.500 revs , on axel stands , that`s ridiculous ..... Why ??
    It`s all controlled by the diff - you`re looking for problems that aren`t there ...

    :hattip:
     
    snotty and matty like this.
  16. Hi Lasty why do you think one wheel was spinning and the other not moving
    Please forgive my lack of knowledge but it seemed strange
    Are you saying that all is normal and not to worry about it
     
  17. So in the cab I looked back at the drivers side wheel which was not moving when I put the van into gear and it only started to move when the engine was reved quite high I’m trying to ascertain if this is a problem ? Theses forums are great to help inexperienced have a go mechanics like myself learn from the experienced people on here some times in need simple stuff to help me understand
    I thank you in anticipation
     
  18. If you stop the one that’s moving the other one will start moving it’s how a diff works
    Have a look on YouTube loads of videos on haw diffs work.

    it’s not wise to run at high revs on stands as there is a risk of it shaking itself off the stands and disappearing off into the distance or the garage wall.
     
    mcswiggs and snotty like this.
  19. It`s all about the diff therefore IMPOSSIBLE to explain on here but the basics are to transfer the power to whichever wheel is spinning . DON`T run the engine and test the theory by grabbing a wheel ..

    This is not your problem - look elsewhere :thumbsup:

    :hattip:
     
  20. Thanks for your replies I think I get the gist of it
    I won’t grab the wheel whilst in gear because that might hurt and yes although I’ve got it on very big axel stands I realise it not safe to be revving the engine thanks Matty and Lasty for you explanation
    I think the gear change difficulty’s have been solved by the new Bowden tube and wing nut adjustment I’ve got about 3/4 inch free play at the clutch pedal before it goes more firm the clutch does seem to engage quite high in the pedal travel should I tighten the wing nut some more ?
     

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