Need your help

[bigfosty]

Some of you may remember me, some may not. I purchased my 75 k10 about 4 years ago, built it up, sold it about 2 years ago, bought it back about 2 months ago. Thought it was good, found out different. Transfer case is on the way out, rear diff may be suffering the same fate, and my pitman arm is about to fall off. I am not sure what to do, money is tight, not sure if it's worth trying to fix. I may have the option of swapping in a transfer case and 700r4 from a 91 chevy 1500. Curious as to what this would entail, if anyone has any experience. Bolt right in? Driveline lengths? How would I hook up the overdrive? Advice? Opinions? I appreciate any help and advice. Thanks.

P.S.- It currently has the np205 all wheel drive transfer case and a th350. The rear diff might just be a carrier bearing, which is pretty easily fixed. My main concern is the transfer case, I have no experience working on them, and very little knowledge on their inner workings.

[Captkaos]

The NP205 is on its way out?  What was the diagnosis?  Those are pretty bulletproof.

Swapping in general is doable, but you need the donors crossmember and the driveshaft will be different.

[Irish_Alley]

capt he also said its awd as in a 203??? got to get more info

[bigfosty]

I was told there is a shaft inside the transfer case with splines on either end, and it sounds like the splines are worn out. I know it's not the best description, but that's the jist I got of it.I may have another donor truck available, it has a np203, or 205, not sure which yet.

[Irish_Alley]

what type of "sound" is it making
shift pattern for the 203 follows
4x4 low lock
4x4 unlock
N
4x4 high unlock
4x4 lock

the 205 is
4x4 low
N
4x2 high
4x4 high

[bigfosty]

I thought the 205 was the all wheel drive transfer case. That's what I have.

The sound I am getting started with a "clanging" sound, when I let off the accelerator, much like the sound you would get with bad u-joints. I removed the front driveline and still got the same noise, the rear u-joints have been replaced. It has graduated to making the same noise all the time not just when deccelerating. 

[Irish_Alley]

if you have the 3 shift positions you have the 205 not full time awd. if you have 4 shift positions you have the 203 full time awd, with the 203 you have to have auto hubs up front or manuals that are locked in order to move the 203 acts like a open differential. unless the 203 has the part time kit installed then you can take out the front drive shaft. one visible way to tell is look at the back part of the transfer case. if you have a drain plug its a 205 if no drain plug its a 203

[bigfosty]

I had the numbers confused then, I have the 203. Automatic hubs, all wheel drive.

[Irish_Alley]

now we know what transfer you have. we can play a game. take the rear shaft out and see if it still makes this noise. also does it make this noise no matter what range your in or any of the 4 drive selections

[bigfosty]

Same noise with or without front or rear driveshafts. Noise happens in all ranges.

[Irish_Alley]

now if you put the transfer case in 4L Lock is there play between the two output shafts/yokes, if you spin one does the other spin right away or is there slop

[Irish_Alley]

one thing. the 203 is chain driven and the chain might of stretched idk. the only way to tell is take her apart. but since she acts like a open differential im not thinking its just going to be a chain

[bigfosty]

Well on the upside, there is a late 70's truck sitting in a field on my best friends property. Asked him about it, he said have at it. It was running when it was left there. It's four wheel drive. So it should have everything I need, so heres hoping.

[Irish_Alley]

good friend. i would still take yours apart just to see what went wrong