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diff problems

Discussion in 'FG Monster Truck / Beetle' started by james22ca, Mar 3, 2007.

  1. james22ca

    james22ca Well-Known Member

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    I had the truck out for the first time today and already ran into some problems.

    The truck would not move, sort of like the diff was blown.
    I took the diff apart and it seemed ok.

    Then it was in the car the diff ring would spin but it would not go anywhere.

    The dogbones and cups are ok aswell.

    Any ideas
     
  2. frumpy

    frumpy Well-Known Member

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    Take off the tires and check the wheel squares yet??:)
     
  3. cyclops1970

    cyclops1970 Well-Known Member

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    and all grub screws .. from the pinion too the diff ring gear .. and also gear mesh ..
     
  4. james22ca

    james22ca Well-Known Member

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    i'll check the wheels

    as for the grub screws, the diff ring gear was moving so I don't thing that that will be the problem.
     
  5. Nomadio_Sales

    Nomadio_Sales Well-Known Member

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    If the diff / diff gear is moving then its got to be the wheels one is loose or grub screw on the axle the power is spinning something look at the drive shafts out of the diff the one that is moving is robbing you of power to move.
     
  6. Nomadio_Sales

    Nomadio_Sales Well-Known Member

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    You do not even have to start the motor spin the spur gear and see where the movement is going.
     
  7. Bigger the Better

    Bigger the Better LSF Plus Member
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    You blew a grub screw in you wheel square. If you take the truck and put it against a non moving object, give it gas and you will see all parts will be moving except the tire - its the square. Take the tire off back the grub out file it flat till the grub has no hole left and use blue locktight and screw it back in tight.
     
    #7 Bigger the Better, Mar 3, 2007
    Last edited: Apr 26, 2009
  8. Bigger the Better

    Bigger the Better LSF Plus Member
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    Oh ya, this is a wheel square:
     
    #8 Bigger the Better, Mar 3, 2007
    Last edited: Apr 26, 2009
  9. james22ca

    james22ca Well-Known Member

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    ding ding ding, we have a winner
     
  10. Bigger the Better

    Bigger the Better LSF Plus Member
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    Good job!
    If you ever screw up the wheel square threads just drill and tap them out larger and you can even go non metric if you want. If you look in that photo of the square I had to after spinning the heck out of the grub and the grub chewing the threads. If that wont work don't go back to the FG aluminum ones go with the Duratrax FH ones they are steel and can be reefed on harder without stripping them out.:)
    http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXHTW3&P=PU
     
  11. Chop Suey

    Chop Suey Well-Known Member

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    Another option is drill a bit bigger and tap the hole for helicoil insert. The helicoil insert is usually made out stainless steel...even much stronger.
    I made a few sets of 9.5mm and 14mm square already...I come prepared for the Summer... You don't know how valuable Summer time is to us up here in the North Pole vicinity...
     
    #11 Chop Suey, Mar 4, 2007
    Last edited: Mar 4, 2007
  12. Bigger the Better

    Bigger the Better LSF Plus Member
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    So true!
    You can never have enough parts.
     
  13. james22ca

    james22ca Well-Known Member

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    What kind of grease/silicon are you guys running in the diff.

    I had the truck out today and it was un-controlable, instant acceleration and instantly sideways. The heaviest stuff I had was 100,000wt diff fluid.
     
  14. Bigger the Better

    Bigger the Better LSF Plus Member
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    Well the stock dif is not sealed unless you silicone it shut and that would be a chore in itself. You can use any high temp grease form the auto store. Higher temp the better. And as for the screaming tires and sliding, welcome to the big torque league! You will get use to the throttle after awhile.:)
     
  15. kengentry5000

    kengentry5000 Active Member

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    I am rounding out the holes in the back wheels on the left rear lately. The engine will rev and the diff is spinning like nuts. I pull the left wheel off and there is a round hole in the wheel where it was square.

    Elcon makes reinforcements for $25/pair but I'm going to try and do a home-brew reinforcement - I need a new RC project :)
     
  16. Bigger the Better

    Bigger the Better LSF Plus Member
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    If you have removed the rear wheels more then a couple times the plastic stop nut will wear out and will back off - Mine is the right side, but figures its the one that spins the correct way to spin it off, specially if its a worn nut. Change them often If you remove the wheels and that will minimized the back out. Sucks though I have the rounded one in the front now.:(