NP203 is Full-time 4WD. Why locking hubs?

Discussion in 'GM Powertrain' started by Opera Man, Oct 6, 2012.

  1. Opera Man

    Opera Man New Member

    I am new to Chev trucks and and have two questions-

    1. I just picked up a 1979 K20 with an NP203 transfer case and manual locking front hubs. I am a bit confused with the configuration. The NP203 is Full-time 4WD. Why locking hubs?

    2. Unfortunately, both hubs are in poor shape. Should I replace them?

    Thanks...
     
  2. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Someone added locking hubs to defeat full time 4wd, probably trying to improve gas mileage.
    This was a common mod to do on these trucks in the early 80's when fuel prices started climbing.
     
  3. Opera Man

    Opera Man New Member

    Thanks much for the reply and clarification. Is there any advantage to going back to the original configuration or should I just buy a set of new hubs and install them?
     
  4. donyms

    donyms Rockstar 4 Years ROTM Winner 1000 Posts

    Welcome to the club, it's good to have you aboard. :glasses:
     
  5. MrShorty

    MrShorty Epic Member Staff Member 5+ Years 1000 Posts

    When my dad did this mod on his '75, the kit not only included locking hubs, but it also included parts to convert the full-time case to a part time case. Perhaps before you worry about going back to the original configuration, do some checking to see if your 203 case is still in the original condition or if it has been converted.
     
  6. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    The advantage would be to save a little fuel, opinions on the strength of locking hubs and fulltime systems range back and forth, I personally think their about even, in the past I've broken both systems under roughly the same conditions.
    Do you know what mfg made them? I haven't looked in a while but Warn (one of the most popular for this conversion) and Mile Marker both offered rebuild kits that were slightly cheaper than a new hub kit. Finding the parts to go back full time might be a little harder to do also.
    Unless the outer hub is broken you should be able to save some money by rebuilding what you have.
     
  7. retired2001

    retired2001 Epic Member 5+ Years 5000 Posts

    Welcome to the G M TC ! Lookls like your getting some good info', good luck!
     
  8. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    Welcome! :great:
     
  9. mfleetwood

    mfleetwood Rockstar 4 Years ROTM Winner 5000 Posts

    *****Thread move here to appropriate section****
     

Share This Page

Newest Gallery Photos