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Are all 203's full time

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by blazin72, Sep 21, 2001.

  1. blazin72

    blazin72 1/2 ton status

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    Are all 203\'s full time

    I have a line on a 74 3/4 with a turbo 350 with a np203 in it,
    I was wondering are they full time 4 wheel drive? All I ever delt with are the 205's
    Thanks


    Blazin 72
    1972 K5 350 vortec, 4 inch lift, with nothing else important.
     
  2. MOABDADC22

    MOABDADC22 1/2 ton status

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    Re: Are all 203\'s full time

    203's are all full time unless a prior owner converted it.

    <a target="_blank" href=http://www.moabdadc22.alloffroad.com/>http://www.moabdadc22.alloffroad.com/</a>Real four wheelers don't need tools to remove body panels, paint, tail lights..etc.
     
  3. chevrules

    chevrules 1/2 ton status

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    Re: Are all 203\'s full time

    all full time unless converted

    chevrules...always has and always will
     
  4. coloradoblazers

    coloradoblazers 1/2 ton status Premium Member

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    Re: Are all 203\'s full time

    I dunno about that. Unless someone changed the tag on my t case, I got part time 4wd. It is an aluminum housing with the little round badge that says new procces, 203, gear:2.61. Am I just reading it wrong or do part times exist?

    K5- because size DOES matter!
    Fear This
     
  5. blazin72

    blazin72 1/2 ton status

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    Re: Are all 203\'s full time

    Well taken that in consideration. Are they worth anything.
    I think I can get the whole truck for $500 cross my fingers.
    It runs now but the motor knocks is it worth it. He said the tranny and transfer case worked great.
    3/4 dana 44 and a 14 bolt in the rear.
    bed rusted but who cares.
    thanks


    Blazin 72
    1972 K5 350 vortec, 4 inch lift, with nothing else important.
     
  6. Jeff427

    Jeff427 1/2 ton status

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    Re: Are all 203\'s full time

    Look closer, it is a 208.

    Jeff427
    <a target="_blank" href=http://muddog.off-road.ws>Mud Dog Off Road Club</a>

    <a target="_blank" href=http://lyonsdesign.bizhosting.com>Lyons Design Web Site</a>
     
  7. blazin72

    blazin72 1/2 ton status

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    Re: Are all 203\'s full time

    Jeff427
    I dont have a clue what came out in them. I dont think its been changed over. I havnt got to go look at it yet.
    but if thats the case is the 208 any good.
    and is it worth having.
    Plus I can identify a 205 but how do I tell the diffrence between a 203 and a 208
    Thanks
    again


    Blazin 72
    1972 K5 350 vortec, 4 inch lift, with nothing else important.
     
  8. michaelm

    michaelm 1/2 ton status

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    Re: Are all 203\'s full time

    203 looks like a 205 to most people. heavy huge cast iron monster with an aluminum tailshaft section.
    where a 208 is all aluminum
     
  9. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: Are all 203\'s full time

    Jeff is replying to colorado who has a 87 that would have a 208. Just misread the tag.
    The NP203 is the next toughest case that was used in the 70's. With a good chain that thing can take just about as much abuse as a 205. I have 2 trucks with them and other than needing to replace a chain after 300,000 miles of full time use they have been problem free.
    Now where 203's get their bad rep is when they are converted to part time you MUST put it in loc for a couple miles every 200 or so miles. The 203 was designed to be lubricated by the oil (Engine oil not gear oil in a NP203) slinging off the chain. There is a resivior in the tail cone that collects slung oil and a small plastic gear acts as a pump and feed it to the tail shaft bearings. That resivior runs dry the tail shaft bearing will burn up. I always park my truck nose down and over fill the case since it's part time. That way the level is higher and every time you go up hill it sloshes oil into the resivior.

    I don't need no damn shop manual, I got a pornographic memory.
    <a target="_blank" href=http://communities.msn.com/OffroadK5s>communities.msn.com/OffroadK5s</a>
    75 Jimmy, Dollar
    Grim-Reaper
     
  10. Jeff427

    Jeff427 1/2 ton status

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    Re: Are all 203\'s full time

    Sorry about that Blazin 72, my other reply was to coloradoblazer, who mis read the tag. Yours is a 203 and the 203 is a good t case especially if it has not been converted to part time (they usually won't stay in high or low loc after they have been converted [at least in my experience anyway]).

    Jeff427
    <a target="_blank" href=http://muddog.off-road.ws>Mud Dog Off Road Club</a>

    <a target="_blank" href=http://lyonsdesign.bizhosting.com>Lyons Design Web Site</a>
     
  11. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: Are all 203\'s full time

    I have figured out what the loc problem is when converting. It's not having the proper endplay in the output shaft. If there is excesive play what happens is the torq pushes the output back. If you look at the cog that is used for loc you will notice that it has a bevel on both peices to help it engage. if the shaft shifts back it gets on to the bevel and pushes out of loc. The end play on that shaft is supose to be about 1-2 thousands. Most people do not add enough shims that come with the conversion kit and get in the neighborhood of 15-20 thousands.
    Also once converted there is more load put on that cog since the spider gears are gone from the diff. 20+ years of crud in the shifter also doesn't help. Going through the shifter and cleaning and regreasing so the detent pin is free'd up helps.
    I have not had a problem with either of my 203 converted trucks once I shimmed correctly and cleaned the shifter. My 75 was poping before I converted it and I found that 25 years of wear had increased the end play. Doesn't do it now. 4.10 gears also helped take a lot of load off the cog. I would have left it full time but I am now running a front locker and that ruled that out. I may go to a OX next year and if I do I will probably go back full time. It sure was nice in the winter.

    I don't need no damn shop manual, I got a pornographic memory.
    <a target="_blank" href=http://communities.msn.com/OffroadK5s>communities.msn.com/OffroadK5s</a>
    75 Jimmy, Dollar
    Grim-Reaper
     
  12. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Re: Are all 203\'s full time

    I imagine, just from the looks of the shifter, that the shifter linkages themselves are an often source of problems for a 203 equipped truck. they even make a 208's linkage look simple!!!

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  13. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: Are all 203\'s full time

    Yeah there is quite a few parts in it to make it work. I have gone through both my 75 and 79. Cleaning them made a big differenct in ease of shifting as well as staying in loc.

    I don't need no damn shop manual, I got a pornographic memory.
    <a target="_blank" href=http://communities.msn.com/OffroadK5s>communities.msn.com/OffroadK5s</a>
    75 Jimmy, Dollar
    Grim-Reaper
     

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