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73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Topic started by: jessem on December 19, 2010, 11:01:03 am

Title: 1979 K10 NP203 Issues
Post by: jessem on December 19, 2010, 11:01:03 am

I have recently purchased the truck listed above and the NP203 wants to pop out of hi loc and lo loc.  Someone has put the conversion kit in the transfer case along with manual hubs.  I checked the linkage (according to the Haynes manual) and everything is lined up.  The transfer case will stay in momentarily, but as soon as the truck needs some torque or the action from shifting from reverse to drive, it pops out into 2wd, if I take my hand I can physically hold it in, but I know this is not helping anything! 

Thanks for all the advice

Title: Re: 1979 K10 NP203 Issues
Post by: thirsty on December 19, 2010, 12:16:10 pm

Check your mount.

Title: Re: 1979 K10 NP203 Issues
Post by: jessem on December 19, 2010, 05:48:54 pm

the mount\crossmember seems to be soild

Title: Re: 1979 K10 NP203 Issues
Post by: thirsty on December 19, 2010, 05:58:39 pm

I had the same setup and the same problem once and found that the rubber and steel had separated on my mount. It looked normal sitting there but I could move the transfer case up with a bar. $20 later for a new mount and it never popped out of 4wd again. Cheap fix on mine.

Title: Re: 1979 K10 NP203 Issues
Post by: jessem on December 20, 2010, 05:31:52 pm

transfer case is tight with the mounts, the shifter feels like it is not going in far enough, I am shifting with the trans in neutral, so no binding?? the linkage is not terribly sloppy either, it may be time for a rebuild??

Title: Re: 1979 K10 NP203 Issues
Post by: topp on December 21, 2010, 09:07:41 am

Check your body mounts. As the frame flexes, the body may be moving, hitting the linkage.

Title: Re: 1979 K10 NP203 Issues
Post by: greenmonster on December 21, 2010, 10:59:56 am

I had the same problem.I just cleaned and oiled the linkage.It has worked fine for 2 years.

Title: Re: 1979 K10 NP203 Issues
Post by: malibu795 on January 01, 2011, 10:04:53 pm

i had problem were the hole int he floor board wasnt big enough and it wouldnt stay in lock.. also adjusted the linkages as well

Title: Re: 1979 K10 NP203 Issues
Post by: Jim Rockford on January 12, 2011, 07:47:45 pm

It doesn't have we a crappy cheap ass body lift does it?

Title: Re: 1979 K10 NP203 Issues
Post by: beastie_3 on January 12, 2011, 10:42:04 pm

Or someone put a 2wd cab on and cut the hole out.

Title: Re: 1979 K10 NP203 Issues
Post by: farmerchris on January 31, 2011, 11:54:43 pm

Had that problem when the guide that the shift forks move on , weared out, on one of my old 203's.Wouldn't stay in gear unless you held it in .At the time nobody wanted the 203,so replaced it with a good one for cheap.