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post #1 of (permalink) Old 03-25-2005, 09:24 PM Thread Starter
 
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Two general GM questions from a former Jeeper.

1) My NP-203 will only shift in 3 ranges - Hi, Neutral, & Lo. [img]images/graemlins/shocked.gif[/img] Any things I can check / adjust to determine if it's a linkage problem or a T-case problem?

From reading about the 203, I understand it should have 5 different selections (Hi Loc, Hi, N, Lo, Lo Loc). It shifts flawlessly between the 3 ranges I can get into..but refuses to budge into Hi Loc or Lo Loc. I crawled underneath and tried to move the 2 rods and only the one closest to the frame (which I assume is the one for Hi, N, & Lo) moves. The other one seems pretty well seized.



2) What is the "proper" way to engage/disengage 4WD on a 79 K10 with manual locking front hubs, TH350, & NP-203.

I had a 90 Wrangler that had automatic hubs and a Posi-Lock to engage the front axle. So to get into 4WD on that, all I had to do was pull the Posi-Lock from the drivers seat and then shift the T-case at will. I've never had any experience with manual hubs so I'm not sure how to go about working them.
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post #2 of (permalink) Old 03-26-2005, 09:34 PM
K5Blazerman77
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Re: Two general GM questions from a former Jeeper.

if your truck with a np203 has manual hubs then chances are you have some type 4x2 conversion kit installed which would change the shift pattern

Have you had this truck very long?
post #3 of (permalink) Old 03-27-2005, 12:01 AM Thread Starter
 
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Re: Two general GM questions from a former Jeeper.

Have had it for a week...picked it up last Saturday.
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post #4 of (permalink) Old 04-03-2005, 11:14 PM
mrbatzloff
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Re: Two general GM questions from a former Jeeper.

On a 2wd converted 203 your shift pattern should be this (starting at the dash side and ending at the seat): 4Lo-2Lo-N-2Hi-4Hi. Locking the hubs before engaging the 4wd from the cab seems to lock the gears in better, but will probably depend on your truck. Truck will probably have to be rolling a bit to engage from 2Hi to 4Hi, for Hi to Lo you'll need to be in Neutral (on the transmission) to get it all the way forward and same for Lo to Hi. On the transfer case itself the outside (frameside) lever IS the Hi-Lo lever, it's pattern being, from front to back, Hi-N-Lo. The inside lever is 2wd-4wd, it's shift pattern being, from front to back, 4wd-2wd (I don't remember if there's a Neutral in there, but if there is it's in the middle).

Your problem could be any one of three things. 1) your shifter's shot; this is common problem with the 203, it's hard to find a replacement, I was lucky to find one from a transmission mechanic's former workplace in arkansas. There is a twin stick available from Offroaddesign.com, it's $170. It's a really neat setup; one shifter for Hi-N-Lo, the other for 2wd-4wd. 2) You're linkage is mis-adjusted (the easiest and cheapest). Get a haynes or chilton's manual and follow the instructions for adjustment. It's really simple. The instructions call for alignment with a drill bit in three adjacent adjustment holes, but the gist of it is getting each lever to fully pull the linkage. 3) jammed or broken fork in the t-case. This is some work and the case probably will need to be pulled. A rebuild kit is about $300, not including the chain (another $120, if needed).

Before jumping to any conclusions or spending any money I would first disconnect the linkage and manually engage the levers using a pry bar. Check to see if your 4wd is working with the hubs in the FREE postion so you can actually see the driveshaft turning under it's own power (rather than from the turning wheels). If you have a body lift it's easy to see from inside the cab with the shift boot removed.

I hope this helps. I went through this whole evolution recently so it's fresh. If you have any other questions feel free to ask.
post #5 of (permalink) Old 04-03-2005, 11:16 PM
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Re: Two general GM questions from a former Jeeper.

Also, I just switched over from a Jeep as well, so it's all new to me-it took some getting used to.
post #6 of (permalink) Old 04-05-2005, 08:58 PM Thread Starter
 
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Re: Two general GM questions from a former Jeeper.

I went through and took the linkage off and checked the transfer case itself. The t-case shifts fine through all ranges.
Upon checking the shifter, I discovered it was covered in an asinine amount of dirt/debris/grime. I tried cleaning it up some..but it was beyond help. So I think I'll grab the twin stick from ORD when I get a chance.

Thanks for the help.
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