NP 203 Conversion Kit

[76/85 Truck]

Hello all! I have a couple of quick questions. I know quite a bit about my truck and how it all works, but I do not know much about the transfer case. I have a NP 203 and a TH350. I was going to buy a conversion kit for the 203 and put hubs on the front end to get it in 2wd, but i didn't know how the kit works. How do I get it in 2 High? I turn out the hubs and put the shifter at what position? The current transfer case only has 3 positions, from front to back: 4Lo, Neutral, and 4Hi. I have heard of 4 lo loc and 4 hi loc but i do not have that. I would be very appreciative if someone could describe to me how to put my truck in 2 lo, 2 hi, neutral, 4 hi, and 4 lo. I suppose i just cant comprehend how i can just have 3 shifter positions, and get it in 2wd . Thanks for everyone who reads!!

[Prong]

Read this: http://coloradok5.com/milemarkerpt.shtml

[76/85 Truck]

Thanks a bunch, Prong. I have a few more questions i hope you can answer. As of now i have 3 shift positions... after the kit install will i still have 3 shift positions? Or will there be more positions after i install the kit?

[Prong]

You should have 5 positions: the "lock" at each end is where the front axle engages. It should be like this:

---towards dashboard---

4 Low lock
4 Low
Neutral
4 Hi
4 Hi Lock

---towards seat---

Once the conversion is done, you'll shift to the Lock position for 4wd. An added bonus is that you'll have 2wd low range.

[LONGHAIR]

Originally Posted by 76/85 Truck

The current transfer case only has 3 positions, from front to back: 4Lo, Neutral, and 4Hi. I have heard of 4 lo loc and 4 hi loc but i do not have that.

Do you suppose that it could have the wrong knob?...though I don't know what it could be from? Every one I have seen has at least 4 positions 2, 4high, neutral, 4 low....in some order.
Are you 100% sure that this is a NP203? Pictures?

[G-REX]

I have a question on the 203 convertion.My transfer has Low lock
Low
Neutral
Hi
Hi Lock on the shift knob.
When I shift into low lock,( spinning by hand)both yokes spin,in low ..the rear yoke spins and the front drags but does not spin, In hi .. the rear spins with drag on the front but is free,,and when in Hi lock, both yokes spin. I've mostly used 205, but this is the first 203 I've used. I'm putting it in with 3/4 ton axles(lock out/in hubs) The transfer case came out of a older wrecker.It seems to have the kit already in it,but not sure.Is this the way the case should act? Any help. Thanks

[G-REX]

I should have added I have a 1985 3/4 ton with 14 bolt rear,It has a built 350 with a 700r4 /208 transfer. Should I swap out for 350 th/203 or leave the 700r4/208 and give it aliitle TLC. ? Thanks

[76/85 Truck]

was the 203 the only transfer case that offered full time 4wd? Because i am 100% positive it is in 4wd all the time. All the way toward the seat, and i have my 4 Hi, and One click forward and i have Neutral. The farthest way, toward the dash, and i have 4lo. How come my transfer case doesn't have the "lock" option? Different version of the 203? or a completely different transfer case?

[G-REX]

do you have a pic of your,it sounds like the pattern for a 205.If you look at the back rear side of a 205 case,it has a round cover plate with 3 bolts in it.

[76/85 Truck]

well i just got off work and took a look at my truck. It has a factory tag on the front of the transfer case that says "Model: 203". With a serial number, and gear ratio. (The ratio said 201 so I'm guessing 2.01? I couldn't see a decimal because i was at a weird angle.) I haven't found a NP203 on the internet with my similar shift pattern yet. Any ideas?

[USSkoval]

The shifters are very problematic, you have all positions but the shifter won't let you get there. It would be best to remove the shifter assembly, then clean it really well and lube it.

[76/85 Truck]

Well, today I had my dad shift the transfer case back and forth while i was under the truck, and there is two "forks" under there. Only one of them moves when he shifts. So i took the linkage to the non-moving one off and tried to move it back and forth and i cant. There are holes on both forks, so i lined them up and put a bolt through them to see if one would move the other, and it didn't. Not sure what that second fork is. Still can't find the loc position. Anyone have any ideas? Thanks a BUNCH for all your help!

[USSkoval]

One fork is for High/Low, the other is for Loc/Non Loc (or 4wd/2wd if it's got the part time conversion). The two holes are for adjustment purposes, IIRC, you line them up with the shifter in Neutral.

[76/85 Truck]

Okay.. So where the linkage that actually moves, it is attached to a silver square of metal. And off that square, the second fork is screwed into it. So what should I do? Keep trying to move it? Because I don't think the 203 came out with a Tcase without having the "loc" option.

[USSkoval]

I don't remember exactly how it all works, I haven't looked in a while. I do know that giving everything a shot of oil will really help free things up. I had a '77 with a bad rear main seal leak... that shifter always worked like butter, lol.

[76/85 Truck]

Lol I'm surprised mine isn't covered in oil. I have a front and rear seal that is leaking. It need some fixing haha. Tomorrow I will crawl under it again and see if i can get it moving. If I can, then i will know for SURE that a conversion kit will work. I was trying to look for a NP205, but I didn't know if I would have to shorten or lengthen any drivelines? Because I know i will need the adapter plate, but I didn't know about the drivelines. Do you know anything about that?

[USSkoval]

Yeah, the shafts are different lengths. I will be doing a 205 swap soon on my '79, I'll just have the shafts re-tubed. Probably better than hunting down old worn out ones the correct length.

[76/85 Truck]

My front and rear driveshafts are 2 piece. The have splines. Would they be able to move enough to be able to fit? Thanks

[76/85 Truck]

My guess is, they move like... 2-4 inches only? About how much are the lengths going to change? Thanks

[LONGHAIR]

The shifters of the 203s are problematic at best. They get stickey from mud/grit and old hardened grease. The easiest "temporary" fix is to simply remove, disassemble, clean and re-lube. This will cure it until the "next time".
The true perminent fix is to convert to what is refered to as a "twin stick" shifter. It eliminates all of the original shifter and it's problems. One lever controls the high and low ranges, the other shifts from 2 to 4 wheel drive.....much better.

[USSkoval]

Originally Posted by 76/85 Truck

My guess is, they move like... 2-4 inches only? About how much are the lengths going to change? Thanks

Hmm, that's a good question. My front and rear shafts are 2 piece also.

[76/85 Truck]

Well... I work at a Carlot/Junkyard mix (the boss owns both of them) so I could go to the junkyard half tomorrow at work and see if i can find a 205 and measure the driveshafts on it (if it's attached to the truck) and see if mine are close enough to work. That would be awesome. Anyone know about how much shorter/longer an NP205 is?

Oh, and I disassembled the linkages again and tried to get it in 4 loc after I oiled them up a bunch, and still can't get it. I think it's jammed or seized or something in that gear. I think I'm going to definitely go with a 205. THANKS A LOT for everyone reading and helping!!!

[Redcap]

The best part time upgrade for a NP203?

A NP205.

[76/85 Truck]

So I believe I found my 205. It came off a Turbo 350, so it will fit my tranny. But I am still curious if i need to change the driveshafts. Thanks for everyone's help. Greatly appreciate it.

[Redcap]

Originally Posted by 76/85 Truck

So I believe I found my 205. It came off a Turbo 350, so it will fit my tranny. But I am still curious if i need to change the driveshafts. Thanks for everyone's help. Greatly appreciate it.

From what I understand from reading on here and other sites, the front will probably be okay but the rear will need to be lengthened.