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Why convert the NP203

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 76_Cheyenne, Jul 4, 2002.

  1. 76_Cheyenne

    76_Cheyenne 1/2 ton status

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    Since the NP203 t-case is a full time t-case, and acts like a differential sending the power to both driveshafts , wouldn't that make it have better on road driving handling and handling in wet and slippery conditions on the road, rather then if you were to convert it to a part-time kit? I understand you get less wear out of the front end by converting it, but what are the other benefits of a part time kit? Sounds like it would be a better all around driver as it is acting like an AWD truck. Any input??
     
  2. BowtieBlazer

    BowtieBlazer 1/2 ton status

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    longer tire life, better gas mileage (probably the number one reason for conversion)....no matter what tires you run full time 4wd will wear the hell out of your tires. This fulltime 4wd also can equal up to less than acceptable gas mileage out of a 350. There was a discussion on this some where not sure where right off hand but that was two of the cons I remember, however I also remember alot of people supporting the full time 4wd traction. and hating that the t-case no longer lubes itself without shifting into 4wd every 2-300 miles for about a mile
     
  3. BorregoK5

    BorregoK5 1/2 ton status

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    One of the other nice aspects to converting the 203 is the low range 2wd position. Had some front end CV shaft damage on a trip which would have completely destroyed the CV to be in Full Time (mid trail) but I managed to complete the outing by only using the front where needed and left the 203 in 2low for the areas that didn't saving it from prolonged damaged use. With a locker, 2low feels almost like 4low did before.
     
  4. thatK30guy

    thatK30guy 1 ton status Premium Member

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    I had a '75 F150 with the full-time crap once.

    I finally had to convert it to part-time when the truck was put into gear and a loud noise started from the underside of the front axle.

    Removed the cover and found out the spider gear internal splines were completely stripped. The truck had logged enough miles on it that the full-time unit had worn everything out to where the front shaft would spin but the truck would not move. I simply removed the front shaft and locked the t-case in 4-Hi to get around town.

    When I got the part time conversion kit, I still had to get replacement spider gears and two new inner axle shafts. Did all the repairs and the truck ran better with the part time kit installed and got better fuel mileage, too.
     
  5. azblazor

    azblazor 1/2 ton status Premium Member

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    The NP203 is a great fulltime unit - we logged almost 200K before rebuilding ours. It handles very well on dirt and snow. Biggest drawback is somewhat less fuel economy and somewhat more wear and tear - which we found to be more than offset by the handling charateristics of the 4WD/AWD on dirt or snow roads.
     
  6. driney

    driney 1/2 ton status Premium Member

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    I had no problems with my 203 leaving it full-time. My tire wear wasn't excessive, but I was running 9.50-16.5's. A wider tire might have been different. Other than replacing the front drive shaft and front axle u-joints I didn't repair anything drive train related in a little over 200k miles. My truck wasn't abused everyday, just the typical construction site stuff. When I wasn't pulling a trailer I got 11-12 mpg (summer, winter was horrible) which I decided I could live with. On snowy roads it would corner like it was on rails, just feed it a little throttle all the way through the corner.
     
  7. 76_Cheyenne

    76_Cheyenne 1/2 ton status

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    I've been driving it with the hubs unlocked and in 4loc, and just started trying to drive it with the hubs locked and in 2hi and I can feel the front tires grabbing on tight corners, as if it was in 4wheel drive. Is this normal? So bascially what you all are saying is its a 50/50 decision. I'll keep thinking about it.
     
  8. driney

    driney 1/2 ton status Premium Member

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    Normal turns shouldn't cause any tire scrubbing. Sometimes on pavement a real tight turn like into a parking spot will cause a little bit of feedback into the steering wheel. Shouldn't be any chirping. I always wondered if it had something to do with the front axle u-joints operating at an extreme angle, but no proof of that.
     
  9. mike reeh

    mike reeh 1/2 ton status

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    dont believe the gas mileage hype! I doubt you will notice any difference. You'll save more gas by driving with the AC off rather than converting to part time. Dont beleive me? Test it out for yourself!

    the tire wear thing is overdone, too. I drove many many miles on a full time '77 K10 and the tires wore PERFECT. yes they were only 31" wranglers, but still.. Like someone said, it might be a little different with a fatter tire.

    The "wear" thing is definately correct. Your front drivetrain will wear much much faster.. But not any faster than the rear /forums/images/icons/ooo.gif

    ...... for a daily driver, I LIKED the full time setup.. it was different, and responded very well. Especially in rainy or wet weather.

    But it IS nice to have 2Lo and 4lo at the flick of a switch (lever)... (and not have to touch the hubs)

    For what its worth im not passing along "hearsay" this stuff Ive personally experienced..

    I love 203's but Im not going to replace my 205 with one /forums/images/icons/smile.gif... I wouldnt hesitate to buy another np203 truck though

    mike
     
  10. i have to say a big reason i comverted mine was so i could do doughnuts at the gravel pit and kick it sideways on dirt roads /forums/images/icons/grin.gif /forums/images/icons/grin.gif /forums/images/icons/grin.gif other then that i really liked the full time action on icy roads.
     
  11. mike reeh

    mike reeh 1/2 ton status

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    Yes! good point! that one totally slipped my mind....
     
  12. NITRO

    NITRO 1/2 ton status

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    U forgot burnouts!! how r u gonna do front wheel drive burntouts?? It makes it all worth while.

    NITRO
     
  13. mlb79

    mlb79 Registered Member

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    The way I see it is we are all driving BIG heavy vehicles with heavy-duty drive trains. 99% of these vehicles are shaped like a brick with a couple of notches out of it. Most of these vehicles have relatively large displacement engines and some of the lucky ones have big blocks (lucky Bas@$%*s). I guess my point is we all love BIG, heavy, blocky (non-aerodynamic), high horsepower, big displacement, off-road monsters. If you want good gas milage, you shouda bought a honda!! /forums/images/icons/grin.gif

    My blazer had a 203 with 33" tires. Love the way it drove. Tire wear was no worse than a blazer with a 208 and 31" tires, that I noticed. Maybe I wasn't paying attention, but I didn't really notice a big difference in gas milage. Although, all things being equal, I'm sure there was a difference.
     
  14. TopOff

    TopOff 1/2 ton status

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    I went from 11 MPG to 15 mpg when I converted my 203 to part time....

    But now it's outta' there!!! /forums/images/icons/laugh.gif
     
  15. BorregoK5

    BorregoK5 1/2 ton status

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    I second that gas mileage with the conversion. I have a 415ci/th350 with 1 ton gear, 38's and 4.56 gearing. Getting an average of 12-15 mpg city off a Q-Jet when I'm not out lead footing it all the time.
     
  16. johnnyK5

    johnnyK5 Registered Member

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    <font color="brown"> I agree that full-time will wear out front drivetrain faster and take a little (stress the word "little") from gas milage because of the extra driveshaft and pinion rotation, but I don't agree that it wears tires out faster. Remember that this transfer case puts most of the power to the front wheels. When not in L-Lock or H-Lock power will go to the Axle with the least amount of resistance. Since the front wheels are set at a camber and steer in the direction of travel - that is where the least resistance is. That translates into putting power to only one front wheel at any given time when you are turning. You are basically driving a big front wheel drive car! I have a 203 and have put approximately 30k on 33" BFG M/T's with way more than half tread left! Thats driving on mainly pavement at highway speeds.
    /forums/images/icons/frown.gif The major con to Full-Time is not being able to do donuts.</font color>
     
  17. 76_Cheyenne

    76_Cheyenne 1/2 ton status

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    Well thanks for all your input guys. Im still not sure of what to do yet. But I'm moving to montana this fall so it might be nice to have this all wheel drive on all the time. We get chilly winters! Butr the drive between montana and Washington where I currently live is about 460 miles. Might be nice to be only spinning one driveshaft all the way there and back whenever I come back and forth. Especially since I get about 8-10 mpgs on a good day.
     
  18. Calclips

    Calclips 1/2 ton status

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    pull the front driveshaft and put it in Hi-Loc. If your only gonna be driving on the highway on the way there it shouldn't make a difference.
     
  19. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    it will improve tire wear if you are heavy on the skinny pedal like me. i would burn my tires off all the time. it does improve MPG, i got 10 with it full time and 15.5 as part time. my buddies burban got 11 and 14.
    grant
     

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