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.

Is my NP203 part-time; x-post from general for possible help

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by dbozman, Jan 17, 2007.

  1. dbozman

    dbozman 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    115
    Likes Received:
    0
    Location:
    Phoenix
    ** I apologize in advance if cross-posting is frowned on. Just trying to get some legitimate help **

    Related to a previous thread here:
    http://coloradok5.com/forums/showthread.php?t=195868

    New-to-me truck. 454 to T350 to NP203. Front axle has lockout hubs installed by PO. I'm trying to determine if this case has got the part-time kit already installed.

    Rig is on jackstands, so tires are off ground. Because of likely screwed-up linkage, I can only find three usable transfer case gears. All the way back, middle position and forward.

    With motor running and front hubs disengaged, I have power to one rear tire in full back spot on t-case. In middle position (neutral I assume), no power. In forward position, power to rear wheel. In all these positions, the front shaft is not spinning.

    Oddly, even when I lock the front hubs in (wheels still in air, thus no resistance), the front shaft is not spinning in any gear.

    Thoughts or insight? I can do whatever other testing methods are necessary if I've approached this incorrectly.

    This is a street rig, and I wouldn't mind keeping the 203 if it's working properly. Thanks in advance for any help.
    d
     
  2. skyyk5

    skyyk5 1/2 ton status

    Joined:
    Jan 2, 2007
    Posts:
    1,537
    Likes Received:
    0
    Location:
    N.E. PA
    ditch the 203 even if it's for street. mine had nothing but problems. i just kept it for the low range box.
     
  3. dbozman

    dbozman 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    115
    Likes Received:
    0
    Location:
    Phoenix
    Any insights on proper testing procedures?
     
  4. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    You should have 5 positions, you are skiping one position on each end of neutral.
    All the way back is Hi loc and if you have part time the front should turn.
    Second from back should be HI i you have part time front shouldn't turn now.
    Neutral is the middle position, next is LOW and here the front shouldn't turn if you have part time. All the way to the front is LOW LOC and here you should have front working if you have part time.
    Note: if you don't have part time, when open you only will have one wheel truning post of the time in the rear.
     
  5. dbozman

    dbozman 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    115
    Likes Received:
    0
    Location:
    Phoenix
    OK, tested some more this afternoon. Took the tranny hump cover off so I could see down. Still only getting three distinct gears on the shifter; all the way back, distinctly into middle (neutral) and distinctly into all the way forward. Each gears snaps into place with authority and I don't feel/see the middle positions I should be missing. I do notice when I'm looking down, that only the upper shift lever is moving; the lower shift linkage is stationary in all three gears.

    Larger issues: As suggested above, I put the rear tires on the ground, chocked them and left the front in the air. Front shaft still does not spin in either t-case gear and with the hubs locked or unlocked. If necessary, I suppose I could bolt a seat back in and take it for a drive (interior is gutted).

    Oddly, when I unlock the front hubs and spin a front tire by hand the shaft doesn't turn. When I lock a hub and spin a front tire by hand, the shaft does turn.

    Thoughts?

    I suppose I'm delaying the inevitable. Based on the pinkish gear oil I drained out, I'm assuming I've got tranny fluid bypassing the seal into the t-case, so I figure the case has to come out anyway. Man, I really didn't want to do that :o

    Thanks for any further insight.
     
  6. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    You obviously aren't going all the way, you either don't have the guts to push harder or the linkage is out of adjustment and the loc lever can't move.
    You are in the 3 positions alright if you don't see the loc lever move.
    On both ends you have one more position that is the loc.
    :D
    The lever will go all the way to the 10 oclock and the 2 oclock.
    Now you are getting the 11 oclock, and 1 oclock.
    :p:
     
  7. dbozman

    dbozman 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    115
    Likes Received:
    0
    Location:
    Phoenix
    OK. I realize I have a problem. Any ideas on how to correct it? It's not an issue of force. Pushing or pulling it any further won't accomplish much other than bending my spiffy chrome shifter.
     
  8. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    OK so you took the tunnel cover off to see what is going on or just the boot?
    You need to remove the tunnel or go under the truck.
    You will need to seperate the linkage from the 2 levers on the tcase, then you put both in the middle position, and then hook your linkage to them and adjusting the linkage to make both fit without moving them
    they need to be aligned when in neutral or the loc won't engage or disengage.
    The rods that connect the linkage is threaded so you need to adjust that part.
    i hope I am not confusing you , I tend to do that sometimes by blabering a lot.
    If you got the idea then it's good, if not then I can give it another try.
    :D
     
  9. 6.2Blazer

    6.2Blazer 1/2 ton status

    Joined:
    Feb 24, 2000
    Posts:
    4,675
    Likes Received:
    26
    Location:
    Ohio
    Not exactly........the 203 case has equivalent to an open diff when in the HI or LOW ranges. This means that the front shaft will maybe spin, maybe it won't.
     
  10. 6.2Blazer

    6.2Blazer 1/2 ton status

    Joined:
    Feb 24, 2000
    Posts:
    4,675
    Likes Received:
    26
    Location:
    Ohio
    Nothing odd about this at all, that's the way it is supposed to work.
     
  11. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    if it's still with a center diff, and the engine is turning, there will be one tire spinning only.
    I know because I had one for a long time and tried, you will sometimes get some drag to turn another wheel slightly, but then the choice will be clear and one tire will spin.
    Now if the engine is off, and you spin one wheel another wheel must turn.
     
  12. dbozman

    dbozman 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    115
    Likes Received:
    0
    Location:
    Phoenix
    That's the way it's supposed to work if the case is still full-time or if it's been converted to part time?

    Guess I'm still putting off the inevitable. The case is going to have to come out if for no other reason than the bad seals.

    Thanks to iceman and all who've provided some guidance. It's appreciated.
    d
     

Share This Page