NP203 Transfer case need help

[75k10]

Ok I just bought a 1975 K10, The guy that had it had said he just had the transmission rebuilt but it didn't work so he got tired of it and sold the truck. The truck runs and when you shift it feels like it goes in gear for a moment but it does not move. It does not have the front drive shaft but when I put it in any gear or shift the transfer case around it always seems to spin. I cant seem to put the case all the way up into L Loc but when I put it all the way down to H Loc the truck seems to jump into gear but I also have idle issues so the truck just shuts off. Also its wierd but when I have it say on Hi on the transfer case and shift the trans all the way to Low you hear a loud ping and it feels like it goes into gear but again the dang thing shuts off.

Any ideas on how I can pinpoint if the trasnfer case is the problem or the transmission or both ?
What is the most common failure on the NP203 T case if there is one ?

any help appreciated

[Irish_Alley]

ok lets start off with this the 203 is kind of like a open dif the power will go to the drive shaft with least resistance in your case being the front. Unless you have it in lock then it will lock the two shaft together, now what could be causing the ping it could be a bad u joint or slop in the rear. first things first fix your idle so you can really figure this out. also low lock can be block if the shifter lever is hitting the floor take the boot off and see how much room is between the shifter and the floor pan when you try to put it in low loc

[75k10]

Ok thanks for the insight, I swaped out the carburator and fixed the idle issue, I then read up a little on how the 203 functions and I installed a front drive shaft. What came next was awesome, I got traction in every gear the truck is alive and moving. Im still having a problem shifting it to L Loc but for now Im happy knowing that the transmission is good. Apperantly the guy I bought the truck from never installed the front driveshaft and just assumed that the trans he had rebuilt was not done right.  Now I just need to put some exhaust into the open headers and its ready to roll.

Thanks 

[Irish_Alley]

There is a part time kit you can install that changes 4 hi unlock to 4x2 hi. Maybe that's what he thought he got. But check if the shifter hits the sheet metal when you try to put it in 4low lock

[beastie_3]

Make sure the linkage is lubed and free of debris/dirt

[75k10]

Ok I checked to see if the sheet metal was in the way and it looks ok it just seems to be jammed and I can't get it go into Low Loc. You mentioned before that the there is a kit to so I have 4X2 in Hi do you know how much that runs ? Where I can find it ? Can it be done with the case on the truck or do I need to remove it ? And is it pretty simple to do ?
Another thing I noticed now that it runs and drives is whining sound coming from the case and as a drive I can feel a big vibration on the transfer case lever. It does leak oil but checked it and it did have enough for the local drive to the muffler shop