Author Topic: Transfer case question: 203 vs. 205  (Read 44856 times)

Offline jharness74

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Transfer case question: 203 vs. 205
« on: May 02, 2002, 08:29:00 AM »
Okay, here's a conversation I recently had with a cousin of mine who is looking for an old 4WD to use as a beater so he doesn't tear up his 1995 Chevy (of course in my opinion he should find a sweet 73-87 to drive and use the 95 as a beater, but I digress...).  Anyway, he said he wanted to find a 3/4 4WD because they have the "bulletproof" 205 transfer case.  I countered that it didn't matter whether or not it was a 3/4, rather what year it was made and whether or not it had the infamous full-time 4WD.  This led to huge discussion and in the end neither of us really knew what the heck we were talking about.  So, can someone enlighten me as to how the transfer case is determined and what the best way to identify the 205 over the 203 is?  Thanks.

Jason Harness
74 GMC 3/4 Camper Special 454/TH400/4.10


Offline 73K20

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Re: Transfer case question: 203 vs. 205
« Reply #1 on: May 02, 2002, 02:07:00 PM »
NP 205's are a part time t-case while the NP 203 is a fulltime case.  The easiest way to tell if you dont know what your looking for is to crawl under the right side of the truck and look on the t-case between the input from the tranny and the output to the front driveshaft.  Here there is small (1"X2") metal tag that will identify the transfer case.  Cheack around the net, there are various places that have pics comparing the two cases.

1973 K20 - 350/350/205


Offline stroked79

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Re-Transfer case
« Reply #2 on: May 06, 2002, 10:36:00 AM »
You can tell the differemce between cases by looking at the rear of the t-case the 203 has a fill plug in it where the 205 has an inspection plate, also the speedo cable is on the driver side output shaft on the 203. Hope this helps

jim


adfas

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NP 203 sucks
« Reply #3 on: May 17, 2002, 09:25:00 AM »
The NP 203 is an aluminum, chain driven, full time transfer case. It is weaker than the "bullet
proof" NP 205. The NP 205 is all cast iron, gear driven, part time t-case. I belive it has a
1.96:1 low ratio. It is found in 73 - 87's with manual transmissions. One way to tell them
apart is to look at the hubs on the front axle. manual locking hubs indicate a truck with the
NP 205 and a man. tranny. Automatic hubs with "4x4" indicate a truck with a NP 203 and a
TH350/400 tranny.  


Offline 73K20

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Re: NP 203 sucks
« Reply #4 on: May 17, 2002, 12:52:00 PM »
I am not positive, but im pretty sure that the 203 is a cast iron t-case.  The alumimum t-case would be a 208.  I can say that it is NOT found in ALL trucks with manual trannys.  Some of the older automatics (mainly TH350 and later TH400) were paired with the NP205.  My truck has a TH350, NP205, and partime hubs.  I think that it is fair to say that a truck with manual hubs will be 95% likely to have a NP205, but it is not appropreate to say that it will have a manual tranny just because it has a NP205.  Anywho, back to the topic, a 203 is a cast iron t-case while the 208 is aluminum.

1973 K20 - 350/350/205


Offline VileZambonie

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Re: NP 203 sucks
« Reply #5 on: May 19, 2002, 07:11:00 PM »
Quote:
The NP 203 is an aluminum, chain driven, full time transfer case. It is weaker than the "bullet
proof" NP 205.

Yes I would definately disagree, The 203 is a heavy cast Iron case.

Quote:
One way to tell them
apart is to look at the hubs on the front axle. manual locking hubs indicate a truck with the
NP 205 and a man. tranny. Automatic hubs with "4x4" indicate a truck with a NP 203 and a
TH350/400 tranny.


I would also disagree here, Auto locking hubs can be put on the front axle regardless of the T-case. The best way to tell if you are unsure is to read the tag.

~Captain's Log~

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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 79GMC4x4

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Re: NP 203 sucks
« Reply #6 on: May 19, 2002, 11:46:00 PM »
One other quick look at the 205 and you should see a small plate in back with three bolts.

'79 GMC shortbed 454 th400 14 bolt FF NP205 Dana 60


Offline oscarone

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transfer case
« Reply #7 on: July 25, 2002, 12:36:00 AM »
The 205 has been known to be a stronger case, but, the 203 when taken care of is pretty good.  Make sure it is service with 10w-40, NO tranny fluid and NO gear oil.
Another reason people don't like the full time case is increased drive line wear.  Conversion kits can be installed, which by the way, would give you manual hubs with the 203.


Offline 83CHEVY

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Re: transfer case
« Reply #8 on: July 25, 2002, 10:17:00 AM »
You guys don't need to get greasy to tell, just look at the floor shifter.  The 205 will have a 2WD postition.  The 203 has H Loc, H, N, L, & L Loc postitions (all of which are 4WD).  If someone has done a conversion on a 203, however, the shifter might read differently (never seen one - so I don't know).  Through most of the 70's trucks, the full time 203 was standard with auto trannies.  I think a 205 could be specified as an option however.

Mike


Offline walnut

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Re: Transfer case question: 203 vs. 205
« Reply #9 on: July 31, 2002, 09:07:00 PM »
i have a 78 silverado with a turbo 350 tranny, manual locking front hubs.  the floor shifter goes from the top, 2 hi, 4hi, n, 4lo.  so would this be a 205?


Offline 83CHEVY

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Re: Transfer case question: 203 vs. 205
« Reply #10 on: August 02, 2002, 12:28:00 AM »
It will be a NP205 if the case is made of cast iron.  If the case is aluminum, it is a NP208.  I am not when they started putting the NP208's in.  I know my '83 has a NP208, but they may not have been around in '79.

Mike


Offline 79GMC4x4

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Re: Transfer case question: 203 vs. 205
« Reply #11 on: August 07, 2002, 10:43:00 AM »
This has much of the info asked for:

www.off-road.com/chevy/f-faqs.html

'79 GMC shortbed 454 th400 14 bolt FF NP205 Dana 60


Offline 83CHEVY

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Re: Transfer case question: 203 vs. 205
« Reply #12 on: August 07, 2002, 10:51:00 AM »
That's a great link.  I added it to my favorites.  Thanks 79GMC4x4.

Mike


Offline randy812

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205 transfer case
« Reply #13 on: September 21, 2002, 10:43:00 PM »
my shifter on my transfer case rattles when driving, any ideas what it could be?


Offline randy812

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205 transfer case
« Reply #14 on: September 22, 2002, 06:56:00 PM »
I think I fixed the transfer case rattle. It was missing a washer and cotter pin on the linkage. Just another day owning an old Chevy! gotta love it.