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FJ60 Clutch problem with NV4500

Discussion in '40- & 55-Series Tech' started by elzs85fj60, Nov 24, 2003.

  1. elzs85fj60

    elzs85fj60

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    I have a nv4500 with a Vortec 350. The problem is there does not seem to be enough adjustment on the push rod from the slave cylinder to engage the clutch. If I pre-load the clutch ( partially engage the clutch) it will work to shift gears etc. however that would mean the throw-out bearing is always engaged(spinning). I know this won't work b/c the cruiser came from TLC and it wore the centerforce pressure plate out in 15,000 miles. Also broke the input shaft nose from the tranny. TLC says they no longer do these conversions b/c of this reason. I know the NV4500 should have an internal throw-out bearing but I also know others are using this set-up. I have heard that rock crawlers aren't concerned with the clearance between the throw-out bearing and the pressure plate b/c they don't see that many miles,where otherwise the throw out would fail prematurely due to constant contact with pressure plate. Clutch master and slave are new and work fine. Does anyone have experience with this problem?
    Thanks
     
  2. ottende

    ottende

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    I'm not too familiar with the NV, but from what you say about TLC it sounds like this is a fundamental problem and does require 'fixing'.

    From your description of the problem you probably three things you can do (unless someone else's experience has provided a proven solution.

    1) Get a slave cylinder with a smaller-crosssection and a longer shaft/cylinder height. You may have to fab a mount for this, but it is the most elegent solution. Find a model that accepts the NV as a neat swap and start there, since that model must have a long enough throw.

    2) Fab an X:1 ratio lever for the slave cylinder to actuate, and then actuate the clutch from the other side of the lever. I envision this would work best if the lever was placed in the current location of the cylinder, and then the cylinder can be placed wherever it will actuate the lever properly. Be mindful of the X times increase in pressure on your system though. Obviously this would require more fabrication than #1, but you won't need to find a different slave.

    3) Add throwout bering replacement to your oil change maintenence routine.

    If no one has a pre-engineered solution, hopefully this will be helpful.

    Good luck!
     
  3. beanz2

    beanz2 Moderator

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    did you use the AA kit? there are two holes on the clutch fork they supply. i used the one farther out from the pivot but it works fine with enough throw. how are your master and slave? i used the stock 75 fj40 parts but brand new AISIN pieces from NAPA. maybe if all your clutch components are a-ok just use the hole closer to the pivot. a bit more effort but you get more t/o bearing travel.

    not all nv4500 uses the internal slave. only 1996+ ones do.

    dave
     
  4. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    [quote author=elzs85fj60/70fj40

    Also broke the input shaft nose from the tranny. TLC says they no longer do these conversions b/c of this reason.
    This sounds like a load of crap from my point of view.

    The input shaft broke because it was not supported properly by the pilot bearing, or because of a problem with trans to bellhousing to engine alignment.

    Who's adapter is making the trans work to the engine? Chev had this combo installed on many trucks pre 96, and it worked fine.