Who sells parts/rebuild kits for the NP 203? The 4x4 doesn't work in low or low-lock in my 79 f150 (lock light also doesn't come on in low lock).

Anyone have an idea as to what causes this?

I posted a similar question in the 67-79 discussion but did not get a reply.

 

Not sure on the cause of the problem other than it might be a mis-adjustment on the linkage (205 myself), if I remember right, it should have two seperate shift links, maybe the one for low range just lost it's pin or such. However I do know that the 203 uses a diff type device for front to rear slipage and locks it up in high or low and uses gears for the reduction like the 205 (thus, the adjustment/linkage thing). As far as rebuild kits, try some places like 4wheelparts wholesalers, nationwide performance driveline, drivetrain specialists (DTS) or even national tire and wheel. Hope this helps!

 

Thanks for the tips. I will look into the linkage adjustment but I suspect it will be more difficult than that because the limited slip feature of the transfer case works in high range but not in low, unless the linkage could somehow be related to that as well-maybe it's not engaing all the way?

 

Yeah, that's what I was thinking, that if the linkage is "out-of-whack", then you wouldn't get low or the lock in low if it can't get into low to begin with. Hope that makes some kind of sense! When checking, you might want to put it into the low position first, then crawl under and see if you can get the linkage to move a little bit farther, after that try with it in the low-loc position, might just be worn bushings not allowing complete movement into the correct position. I'm still leaning towards this because you still have the loc in high range. Hope it's something that simple!

 

 

Well, after doing some careful driving and poking around under the truck, I determined that it was a linkage problem. The shifter does not go forward enough to either lock into the low lock setting or make the lock light come on. The limited slip feature works in both high and low range, though, not just in high as I had previously thought. I've had several people offer up their part-time transfer cases for a conversion, but this case seems to work pretty good--I just drive, no turning hubs in and out and pulling on levers. It seems to hold the road better than the part-time setup, too. So I will probably keep it until it blows up. Now all I have to do is somehow get at the linkage way up on the transfer case.

 

My NP 203 is messup up too. I just spend a bunch of money converting it to parttime, and now I have no four wheel drive period. The chain looked good, and the conversion basicly replaces the little differential with a gear. I have high and low range but no four wheel drive. I can lock my hubs and make the drive shaft spin from the axle end, but not from the transfer case.

I can drive it now anyway. Gonna take the housing apart again this weekend and check the internal linkage. If that looks good, I'm just gonna replace the damned thing with a NP205.

BTW, there is a BIG difference between a functional 203 fulltime setup and the parttime. You'll really notice this is you like to fly in the rain.