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Talk me into a NP205, or not...

Blue85 said:
What does the age of the lift have to do with a driveline clunk? Usually the clunk is in the differential spider gears. Old 10-bolts can have a lot of pinion rotation before the all the slack is out. The chain in the transfer case is only for the front drive. If you have unlocking front hubs and/or the part-time kit is disengaged, a loose chain won't have much affect on anything.
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I guess I was referring more to the bigger tires wearing on the chain and putting more stretch on it over a period of decades than if it was running 5" (or more) shorter tires.

But, what I hadn't considered was what you just said about the chain only effecting the front drive and currently the front drive shaft is off the truck and has been since I bought it. I guess I need to have some one watch the driveshaft whenI shift into gear to see what's making the noise
 
MountainmanID said:
I guess I was referring more to the bigger tires wearing on the chain and putting more stretch on it over a period of decades than if it was running 5" (or more) shorter tires.

But, what I hadn't considered was what you just said about the chain only effecting the front drive and currently the front drive shaft is off the truck and has been since I bought it. I guess I need to have some one watch the driveshaft whenI shift into gear to see what's making the noise
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Front drive shaft is out? Do you have a part time kit? I pullled my dshaft and xfer wouldnt stay in gear. It would pop out so i had to hold it to drive it home after throwing a universal.
 
It does not have a part time kit that I am aware of. The PO stated he pulled out of his driveway and went to make an immediate turn onto another street when one of the Ujoints busted on the front drive shaft. He said it wouldn't move until he shifted to "HIGH LOCK", then it drove fine and was driven that way for over a year before I bought it and about 200 miles since I bought it. He also said the truck seemed to get a little better gas mileage too. The front just has spline caps, no locking hubs.

I found replacement chains for $175-250 depending on width, apparently there were a few different widths and link counts in the 203. Thats basically the cost of a 205 that needs rebuilt. A few 241s have also popped up on the local craigslist, but that may necessitate a whole new trans if an adapter is unavailable for the TH350.

I wish Milemarker still made the part time shaft kit. I don't like the idea of the tiny little tabs of spider gears being used to lock the diff inside the tcase. I'm really thinking there's gotta be a way to just weld the gears? I'm watching a bunch of youtube vids on the 203 right now and have an exploded parts diagram taped to the ceiling over my bed to stare at while trying to fall asleep. If I can get a stout part time kit, and it turns out my chain isn't too stretched, I'll probably stick with the 203.
 
I recommend if you stick with the 203 with pt kit you make sure to run the solid steel 2 piece diff carrier
The stamped one is a major weak link
Don't know which is in your t case
But worth checking out
 
Recon 78 said:
I recommend if you stick with the 203 with pt kit you make sure to run the solid steel 2 piece diff carrier
The stamped one is a major weak link
Don't know which is in your t case
But worth checking out
Click to expand...


I'm definitely going to find out. I just read a 4wheeler article about the 203 from 1997 that stated that guys would often take out the front shafts and put it in High Lock to gain a MPG but it also stated that running it in Lock for extended periods of time leads to CLUNK! from slop developing in the internal coupler on the differential. If the guy has been driving it for a year like that its possible he started the T-case down a path of destruction.

Here's the article, its a simplified explanation of how to freshen up a 203: http://www.fourwheeler.com/how-to/47538/

If the differential is a little whacked, I think it makes even more sense to weld the spiders and get a square piece of plate steel cut out to reinforce the center of the spiders. That's how we used to weld up the diffs in 240s and various other RWD nissans for drift work.
 
When the t case is stock the slipping of the full time releases the tourqe so it's not too bad
When you lock it out with a pt kit it can't release and snaps like a twig

I do agree tho
Not stout enough
 
to the o.p. if you plan to rebuild the np203 its harder and more money that doing a 205 . yes there is other factors for the swap . but rebuild case for case its cheeper to do the 205 and not think of weak points . also do the twin stick mod and have rear AND front control of 2h-4h-4l .

and to others yes i know you can twin stick a 203 . but not as many options of twin stick as 205 .
 
that be what you need . looks all there . and possible newer adapter on it . hard for me to tell in them pics on my shop computer screen .or its got a 700r4 to th350 spacer plate stuck on its face of the adapter .

and 275 not a bad price point with adapter and shifter included .
 
That's what you need. It has the spacer to use it on a 700r4 but you won't use that. Make sure the coupler splines are nice.
 
I told him to keep the shifter and I got it for 200 since I'm gonna build a twin stick anyway. Time to order some seals and freshen it up!

Edit: Shifted into all gears nicely and was very tight. Input splines look nice and crisp. Just gotta find that front bolt on yoke.
 
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Unless I'm missing something big, The 203 and 205 seem to have two entirely different yoke setups.
NP203 (still on truck)
0803182013.jpg

NP205 (recently acquired)

0803182013a.jpg
 
Sometime around the mid 70's GM switched from the yoke pictured in the top photo to the 4 bolt style...

I know "some" NP-205's had the same splines and size for the front yoke so they could be swapped to an NP-203 but I'm not sure if that is true for all years and models..
 
I, personally, flogged the tar out of a 203 while my buddies were yelling I was gonna blow the (TH350) but it was in a blizzard, stuck in a culvert and I wasn't walking without a darn good reason. It finally came up out of it and was still going strong when I sold it so I think all of them are a lot stronger than we give'em credit for. However, my son's '67 BBC has a TH400/205 (which I built) and I doubt you'll ever need a stronger auto tranny/case combo.

ETA: The adapter between the 400/205's are scarce and pricey, probably worth half the $400 combo cost!
 
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