203 xfer questions

[gregbr]

The 67 SWB 4WD came home today, and I need help on the xfer case.

1.It's a 203 (has the label), so what is the shift pattern?

2.Is the 203 correct for these trucks?


Edit: Wrong transfer case installed, but it still rolls in park. Any ideas??

[Scrubby]

The 203 is the full time 4wd case from the 73-79ish trucks. So, no it is not correct for these trucks.

The original shift pattern (from the front) is: Low lock, low, neutral, high, high lock. If you have hubs on the front axle, my guess is this case has a part time kit in it, so the shift pattern is probably: 4 low, 2 low, neutral, 2 high, 4 high. With the part time kit, the front shaft should only turn in 4 low and 4 high. If it turns all the time, then the case does not have a part time kit, and you need to leave the hubs locked to move the truck at all.

Provided it has a part time kit, you should be fine. It will operate just like the rockwell or np205s that came in these trucks.

[gregbr]

Are the 203 & 205 xfers exact replacements for one another...can I just swap back to a 205 without doing anything else? What's the differences in the 205 verses 203?

I'm confused, my xfer shifter is all the way toward the seat, and when I move the shifter forward one notch it appears to be neutral. Is this correct or am I missing something.

[ehjorten]

The 205 and 203 transfer cases can be swapped, but it is not a direct transfer. You will probably need a new adapter (probably from www.advanceadapters.com ) and there will be other minor changes. A NP203 is a full-time transfer case (factory) and the NP205 is a part-time transfer case. The NP203 is chain drive and is quite heavy and bulky, but a very good transfer case. The NP205 is smaller and weighs less. It is generally regarded as the strongest of the transfer cases.

As to the shifting of the transfer case. in normal operation if you shift forward one space you are correct in that you have shifted to Neutral. In order to shift to 4WD you need to shift rear one position (the rear-most position) to Hi-loc (this assumes your transfer case is converted, which it most likely is because of the manual hubs).

(front of truck)

Lo-loc
Lo
N
[Hi] - starting position
Hi-loc

(rear of truck)

[Bowtiefreak]

Sorry,
Don't mean to steal the post but can a truck with a 203 case be driven without the front shaft in it. (The truck does not have lock outs on the front)

[Scrubby]

It can be, but you have to be in one of the "loc" positions.

I wonder if that is not what is going on with gregbr's truck. Maybe the 203 was swapped in and a part time kit was not put in it. That would mean, for the truck to move it would have to be in high loc or low loc. High would just act like nuetral, but I bet the front driveline is spinning.

The best would be to find a tranny/case combo together and swap that in. I don't know about the length, but I think the 203 is longer, so you might have some rear driveline mods to make. The easiest would probably be to get a part time kit and put that in. The 203 is not a terrible case, and it has a lower low range than the 205.

[smokekiki]

Yes the 203 is longer.It is pretty easy and cheap to put a part time kit in.You just need the transfer parts since you already have the hubs.It is done with the case in the truck.It is not recomended to drive without a front shaft.With the part time kit You need to put it in 4wd every 200 miles.I do it when I fill up.You just need to drive a mile to lube the rear bearings.

[smokekiki]

Here is site with info... http://www.coloradok5.com/milemarkerpt.shtml

[gregbr]

I finally go to look at it some today. Scrubby hit it dead on.....I have to be in hi loc to move at all, and in hi it will not move but the front shaft spins. So, it has NOT been converted to part time. I also played with another 203 out of a 76 3/4 ton and it is different. It's sitting on the groung all hooked up to the trans, so I'm spinning the shafts yokes by hand. In hi position I spin the rear and the front yoke does not spin. If I pull it to hi loc, turn the rear yoke they both turn. So, this one has been converted to part time??

I also found the truck will not "park". With the auto trans in park and in hi loc with the hubs unlocked......you can push the truck (on a hill) and something pops and the front shaft jerks and the trucks rolls a couple inches. Is the xfer hosed up inside??

Thanks

[smokekiki]

Transfer should be alright.With the hubs unlocked,it thinks the front wheels are spinning and is sending the power to the front.It has a differential in the case.The part time kit does away with it.

[gregbr]

WOW, Thanks for the great help!! Where can I get the part time kit and how hard is it to install?

[Mudder]

Most parts stores should have them. Thinking they are Mile Marker. Not sure tho.

[smokekiki]

Yes,mile marker is the one to get.I have not talked to anyone who has had good luck with superwinches kit.

[gregbr]

I finally got a few minutes to mess with the 4wd today....trying to figure out why it rolls when in park. I thought we had it figured out from the previous comments, but, today I locked the hubs and it will still do the pop & roll a few inches thing. Any more ideas?

[gregbr]

ttt

[ehjorten]

With the center differential (which is an open differential) and the front hubs unlocked I would expect that the rear wheels could turn because the center differential would turn the front shaft backwards and the tranny output would stay stationary. However, when you locked the hubs, it should prevent this "back-driving" of the front shaft. Either your parking pawl is messed-up in the tranny or maybe more likely your front hubs are not engaging properly (possible needing replacement).

[gregbr]

Thanks ehjorten, I check the hubs tomorrow....Tuesday before I look in the tranny.