Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

NP203 shift pattern

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by DANOK5NH, Mar 6, 2001.

  1. DANOK5NH

    DANOK5NH Registered Member

    Joined:
    Mar 6, 2001
    Posts:
    6
    Likes Received:
    0
    Location:
    loudon NH
    Hi, I'm kinda new to this site but have had my K5 for about a year. It's a 1983 Jimmy w/ a built 350, th350 w/ a transgo shift kit, an NP203, stock axles/3.08's and 31's. I also have a 4" lift in the garage. So my question is, what is the shift pattern for this T-case? I've heard something about a "hi-loc lo-loc" but don't know much else other than where low and high are. One last thing, will I have to modify my driveshaft(s) to install my 4" suspension lift (when it warms up)???
    Thank you in advance

    DANO



    If you ain't stuck, you ain't tryin!!!!!
     
  2. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    Deja vu! I just answered this in a different thread... [​IMG]

    DANO, the stock shift pattern for a 203, is:

    Lo-Loc (Low range, center diff locked)
    Lo (Low range, center diff unlocked)
    N (No drive to alxes)
    Hi (Hi range, center diff unlocked)
    Hi-Loc (Hi range, center diff locked)

    If it's been converted to part-time, then the pattern is somewhat different, since the case won't have any full-time 4WD postions any longer. I've never had a converted one, so I'm not sure how they shift after you do that to one. Mine had a 203 for about a month before the 205 went in... [​IMG]


    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     
  3. DANOK5NH

    DANOK5NH Registered Member

    Joined:
    Mar 6, 2001
    Posts:
    6
    Likes Received:
    0
    Location:
    loudon NH
    Thanks, do you have any idea where to get one of thse conversion kits or how easy it is to install?

    If you ain't stuck, you ain't tryin!!!!!
     
  4. Sparky

    Sparky 1/2 ton status

    Joined:
    Aug 20, 2000
    Posts:
    423
    Likes Received:
    0
    Location:
    San Antonio(summer) Texas A and M (school year)
    you can get the conversion kit from Four wheel parts. There are two kit offered. One is a crown gear kit. That basicly wedges the spider gears on the 203's diff shut. The other (more expensive one) is a shaft kit that replaces the old output shaft and diff with a new one that has no diff. The shaft kit is much stronger and better. I would not recomend the crown gear because when they get old you will have alot of play in the drive line. Espessialy if you wheel it alot. Also, if you want the part time kit you have to get lock out hubs instead of the permenantly locked ones you have now. Mile Marker offers a kit that includes there good hubs. They are all very easy to instal. The directions they give you are not very good, but common sense takes care of the rest. You might want to look around for other places that sell them online. You can probably find it cheaper than 4wheel parts. Try Off Road Design or something like that. The only special things you will need is a big ass socket (i think Inch and 5/16) and maybee some snap ring pliers, but the plieres are not absolutely necessary.


    Sparky

    When all else fails... Check the blinker fluid.
    78 K-5
     
  5. Blazer79

    Blazer79 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,816
    Likes Received:
    0
    Location:
    Guatemala, Central America
    Why would you want a part time kit if you have the beauty of full-time 4wd? Mileage? It won't improve as much as you think. Not enough to justify the kit.

    <font color=blue>//////
    <A target="_blank" HREF=http://blazer79.coloradok5.com>http://blazer79.coloradok5.com</A>
    </font color=blue>[​IMG]
     
  6. lv2whl

    lv2whl 1/2 ton status

    Joined:
    Mar 4, 2001
    Posts:
    130
    Likes Received:
    0
    Location:
    CA, USA
    i had it in my last blazer (part time kit) and i loved it. Its alot easier to spin doughnuts, not that i would. And your driveshaft should be fine.
     
  7. Hank75

    Hank75 Registered Member

    Joined:
    Nov 30, 2000
    Posts:
    31
    Likes Received:
    0
    the stock shift pattern for a 203, is:

    Lo-Loc (Low range, center diff locked)
    Lo (Low range, center diff unlocked)
    N (No drive to alxes)
    Hi (Hi range, center diff unlocked)
    Hi-Loc (Hi range, center diff locked)

    what does center diff locked or unlocked mean??????
    i have 203 case with warn part time hubs.
    thanks
     
  8. DMK

    DMK 1/2 ton status

    Joined:
    Feb 20, 2000
    Posts:
    757
    Likes Received:
    0
    Location:
    CINCINNATI, OH
    Unless some one changed cases you should have a part time 208. There is a tag on the back of the case. 208 is aluminum and 203 is cast iron.
     
  9. prjt_blzr

    prjt_blzr 1/2 ton status

    Joined:
    Mar 4, 2001
    Posts:
    352
    Likes Received:
    0
    Location:
    COS, CO
    I agree that if it is stock it should have the NP208 T-case. Is the case cast or aluminium? A cast case will be the NP203, the aluminium will be a NP208. You could also look to see if you have a slip yoke output or a fixed yoke output on the rear driveshaft. I believe that only the NP208 used the slip yoke. When a NP203 is converted to part time use the shift pattern stays the same. The change is that LO is now 2wheel LO and HI is now 2wheel HI. If you want a kit that is an install and forget about, use the replacement shaft. I broke 4 of the crown kits. A big block and a heavy right foot didn't help but replacing these things every 6 months was a hassle. Most 4" lift kits require a driveshaft "fix".
     
  10. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    Hank, full-time 4WD systems have a differential inside the transfer case that allows the driveshafts to spin at different speeds. This keeps the drivetrain from binding on hard surfaces. But it will also allow only one of the driveshafts to spin in the really nasty stuff off-road (Just like one tire will spin on a non-posi axle). So the "Loc" postions lock that differential and force both driveshafts to spin at the same speed. The Loc is for off-road, slippery surface use only.

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     

Share This Page