78 K20 w/ NP203 lost 2wd???? Need help ASAP

[ChevyJoe]

78 K20 with 350/350/203 with conversion kit. Has locking front hubs. Parked at a friends in 2wd, we all left, came back, wouldn't move in 2wd, heard grinding trying to put it in park.
-HUBS UNLOCKED- 4HI and 4LO will move the truck with no noises
-HUBS LOCKED- 4HI and 4LO will move truck with no noises

Did something happen with the 2wd gears inside t-case? Any help is appreciated

[74k20]

I "lost" all forward motion once when I put the t-case in "lock" to frequently lube up the t-case due to the part time kit.  Come to find out my t-case linkage shifter arm nut came loose thus not actually engaging the t-case into a gear.  I had to hand help the lever forward just to get it in the driveway.  So have someone move the t-case shifter, and you look under the truck to make sure you are not wobbling around and not engaging.  Hope it's that easy for ya - good luck.

[rich weyand]

You have the transfer case in neutral.  The "grinding" you hear trying to put it in Park is because the output shaft of the transmission will spin as long as the engine is running.

[Chadwick717]

Yeah with a 203 and the conversion the 4HI is effectively your 2wd

[rich weyand]

You should probably clean out the np203 shifter box to make sure it is jiggling all the rods correctly.  They fill up with road dirt and grime and get sticky and flaky.

This works.  Remove the boot and soak the shifter box down with Silikroil or PB Blaster.  Let it sit overnight.  With the engine off, run it back forth through all five positions, then soak it down again as you move it back and forth through the positions to rinse the guck out of it.  Finally, pour a few ounces of motor oil down through it to lube it.  It should be silky smooth at this point.  Replace the boot.