78 Chevy K10 Transfer Case Question

[guroojedi]

My son and I bought this truck to fix up and drive (functional and pretty).

According to the VIN it had a 400 engine in it, but we were told it was swapped to a 350 engine before we bought it. He didn't say if he swapped the tranny and T-Case also.

The 4x shifter is stuck in (what looks like) 4H. I think a rebuild or replace is in order but not sure if it's a 203 or 205.

It looks like 203 but that lower right plug seems out of place ....

[Rapid Roy]

Welcome

[guroojedi]

Thank you

[Captain Swampy]

The 203 is full time 4x4. The shifter would say Hi loc, Hi, N, Low, Low loc. The one in the picture doesn't look like a 203.

[guroojedi]

It does say Hi loc, Hi,N, Low, Low Loc

Any idea what it may be?

[Captain Swampy]

Actually I think it is a 203. There is a set of spider gears in the rear housing. It locks them in the loc positions so the front and rear drive shafts have to turn. Another thing is from the factory they just had covers over the front spindles as they didn't use locking hubs.

[Captain Swampy]

http://forum.73-87chevytrucks.com/smforum/index.php?topic=30295.0

[ehjorten]

That is a NP203.  It is a full-time 4wd transfer case.  From the factory they did not have selectable hubs.  Many were converted to part-time 4wd to save on front-end wear.  In that case there is a kit that goes in the back of the case to lock-out the center differential.  You then put on selectable hubs on the front.

[75gmck25]

If there are fixed hubs on the front axles, its probably an uncoverted NP203.  In stock form (no conversion) they are very reliable, but boxes converted to part time may not have been maintained properly to ensure the internal pump circulates oil.

There are several sites out there that explain how to adjust the shift linkage on the NP203.  Mine has always worked fine, but it seems like many folks have trouble with the linkage.

Bruce

 

[Irish_Alley]

cant disagree only add to whats been said. 203s have no "drain plug" unlike the 205, to drain a 203 you remove the lower two bolts in the cover on the lower right side. that plug on the right side isnt really a plug but support bracket that should go to the bell housing. if you remove the trans for whatever reason put the bracket back in place.

if you also notice there seams to be a box in the lower left side of the T-case thats actually because the Np203 is a two piece setup unlike the 205. some people will take the front gear box and attached it to a 205 to make the "doubler"  for a 4:1 low range
 

unless you plan on rock crawling dont waste your time or money on it.

about the handle being stuck, jack the truck up and try to rotate the tires sometimes the hubs will get stuck and even with manual hub they'll stay in 4x4 and will bind up the transfer case making it almost impossible to remove out of gear. 

[guroojedi]

Thank you everybody - very good info here

[JohnnyPopper]

Welcome from another newbie!

Miles Marker makes the conversion kit. I think they still make the front locking hubs.