Np203
 

When I shift my np203 it feels like there are 4 positions where the shift lever rests. I had assumed it would have been 2H, 2L, N, 4L, 4H but it doesn't feel that way.

I have lock/unlock hubs on the front wheels. I don't know if it has an anytime kit. How can I figure out how to work this or what's going on?

Re: Np203
 

I had a 76 Blazer with a 203 years ago.

The Shifter plates inside were worn and gummed up with mud and dried up grease.
It made it very difficult to get it into 4wd.

My solution at the time was to make it a 2-lever shifter.

This may or may not be the issue with yours.

If you disconnect the shifter and manually shift the transfer case,
you will be able to tell if it the Transfer case causing the issue or the Shifter causing the issue.

Re: Np203
 

The shift pattern for the NP203 (starting from the dashboard shifting rearward) is as follows;
L Loc, L, N, H, H Loc
One way to find out if you have a part time kit installed is to unlock the front hubs and leave the transfer case in either L or H. If no part time kit is installed then it will send power to the front axle, making everything turn but you won't move since the hubs are unlocked. The differential inside the 203 sends power to the wheel with the least resistance (front or rear) when the shifter is in L or H, in either of the Loc positions it will send power to both the front and rear. If you leave the hubs unlocked and shift into one of the Loc positions it should drive normally but again everything up front will be turning. There is no true 2 wheel drive with a NP203 as it left the factory. This is explained fairly well in the owners manual too.

Chances are if you have hubs on the front the transfer case has been converted with a part time kit. My understanding is with a part-time kit installed the shift pattern is changed to (front to back) 4L-2L-N-2H-4H.

Re: Np203
 

Thanks for the info. So from the factory with no loc/unlock hubs, how did the truck behave in L versus L loc?

Re: Np203
 

Yeah, something weird is definitely going on because this transfer case only has 4 positions and it should definitely have 5. If i get a better look at it from under the truck will i be able to figure out what's going on?

Re: Np203
 

Let me tell you the story how I figured out at age 20.;)

Stuck at a Clay Pond (Becauce of a Snapped U-Joint)
One axle not pulling = You are not moving:lol:

There is plenty of info online about this now.

There is a kit like this in the link below.

You take the Spider gears out and use these Wedges to make it a Solid shaft.(Kinda) ;)

Link:
https://www.summitracing.com/parts/mmk-501

They also make a solid shaft now.
Maybe someone else has used these.
I will try to find a link for the One piece shaft.

Re: Np203
 

My '74 K20 was originally a SM465/NP203 setup. Driving a manual with the 203 wasn't real fun, lots of lurching and hopping.
Anyway, in L it would essentially be 2wd low range, but again the transfer case would send the power to whichever wheel had the least traction. Typically this was a front wheel. Same as driving around in H but much slower of course.

L Loc is like driving around in 4 lo. Low range four wheel drive, front and rear axles are getting power.

Re: Np203
 

So in L or H, the power would go to the wheel with the least amount of traction. Does that mean that if you had a few tires stuck in the mud they'd have the least amount of traction and then they'd get the power?

Seems like it would work better to send power to the wheels that had the most traction. But I don't know if I'm understanding this correctly.

Re: Np203
 

The differential within the NP203 is essentially an open differential and works just like a rear axle with an open differential does. The wheel with the least amount of traction gets power sent to it, remember in L or H you're in essence in 2 wheel drive. So if your front wheels are in mud and rear on solid ground the fronts will spin and vice versa. If all your wheels were in the mud then only those that had the least traction would spin, then you would shift into L loc or H loc and both axles would be engaged.

Re: Np203
 

Thanks. I really appreciate the great info. :)

Re: Np203
 

I have searched high and low.

A company used to make a solid shaft for the part time change-over.

I did find the other kit that was available years ago.

Looks like it was Discontinued also.

Here one link on Amazon with a picture of it.

Link: https://www.amazon.ca/Superwinch-900.../dp/B000CPJMWK

Your 203 may already have one of these kits in it.:chevy:

Re: Np203
 

Would there be any situation or reason to drive in L or H with hubs locked if a person for some reason had locking hubs but no part-time kit?

Re: Np203
 

It's just AWD for day to day driving and go-anywhere readiness. I only lock mine when I get stuck or am about to get stuck. It will go through a lot of crap in just AWD.

Re: Np203
 

Thanks. I did some testing and it behaves like I do have the part-time kit. :)

Re: Np203
 

After playing with this for a month I see that I can't get into H loc. When I pull the shifter all the way to the seat, I feel a click and when I let go it moves back to H. What should I do to fix this?

Re: Np203
 

Hey do you lock the hubs and them move the shifter to H loc or the other way around? Does it matter?

Re: Np203
 

The shifter has 40 years of crud in it. You can probably clean it good enough without removing it by spraying a whole can of Break Away in there while moving the lever. I usually remove it to give it a good cleaning. Then it shifts as smooth as butter and good for another 40 years.

Re: Np203
 

If you disconnect the shifter and manually shift the transfer case,
you will be able to tell if it the Transfer case causing the issue or the Shifter causing the issue.

Re: Np203
 

Okay, do you open it up to spay it or is there an open spot? I assume there is since dirt can get in.

When you say you remove it to clean it thoroughly are you pulling off the whole transfer case and disassembling it partially?

Re: Np203
 

Great idea, Ill give that a shot.

Re: Np203
 

Best I Recall
There are 2 bolts that hold the shifter assembly on.
you can take those out and the linkage loose then remove it.
It has a bolt on one side of the cover of the shifter assembly.
Then there is a tang that is bent to hold the other side on.
Just take some Pliers and bend this tab just enough to get the cover off.
Remember to keep up with how the levers and pieces are positioned in there.
So, you can put it back correctly.

Re: Np203
 

I suppose that will make more sense when I pull that cover off and look in there. Would I simply take a picture so that I can youse the picture to set things as they were before replacing the cover after cleaning?

Re: Np203
 

Yes
Also lay them out as you clean them.
keep up with the order of them side to side and what was towards the front.
Then you will be okay.

Re: Np203
 

Perfect, thanks!

Re: Np203
 

Yeah, I just remove the shifter and spray it good. I don't take the cover off the shifter or take it apart. I guess I get it clean enough without taking it apart. They sure shift nice and smooth when they are clean.