NP203 vs NP205
 

What is the best way to distinquish between these two (2) transfer cases?

I believe I have an SM465 in front of one of these and the output flange on the transfer case is a flange with a large nut in the center.

Are both of these cases gear driven?

The NP 205 has a round access cover in the middle of the back of it. It is about 2" around with 3 bolts.

The NP203 is a chain driven, full time 4wd case. There are kits available to make them part time. The 203 isn't considered as strong as the 205 and they are heavier. If you have apart time kit in it, you need to put the truck in 4wd once in a while because they use the chain to bring the oil up to the top of the case for lubrication.

Thanks bouncy, I am assuming the NP205 is gear driven. Is this correct?

What is the purpose of the 2" access cover?

the 205 is gear driven. Here's the back of a 205:

http://img.photobucket.com/albums/v2...s/000_0808.jpg

The 205's are gear driven and about 12" long with an short output. The NP203's are about 22" longwith a gear driven reduction box but is chain driven with a long aluminum output and this transfer case is actually 4 pieces bolted together.

Its funny though, all the current transfer cases, even those used in the big Dodge and Ford diesel trucks use a chain drive case. These current chains are about 1/2 the size (in width) of the NP203's chain....in other words, saying the 203 is weak is like saying that a 205 is weak, it just aint so!!!

I believe they meant the 203 is weaker than the 205.

I definately didn't say the 203 is weak, just weaker than a 205. You won't find a lot of rock crawlers running a straight 203 (although they do use them for doublers.) I have a 203 in my '69 and the stock 205 in my '72. I had the pleasure of dropping the 203 from my '69 once. I was heavy & awkward.

next time you need to drop a transfer case, or better yet, a tranny & transfer case combo, do what I do....place a cherry picker/engine hoist in the open passenger side door, with the boom extending inwards, with the end (hook) over the transfer case shifter hole, drop a chain down through the hole and bolt it around the combo at the adapter, tighten up the slack on the picker, unbolt the crossmember bolts, and lower away!!! Works great!! I been doin em like this for 20 years!!! :b69:

what i hate about new trucks ('88 & Up) is that all the trans/transfer case setups are aluminum, if you roast a bearing, the case is probably scrap gimme cast any day

I got a 208 (aluminum, chain driven) in my chevy and its taken a beating with no poblems. However ive seen them break, usually from beign bottomed out by the front drive line or being high centered. Ive also seen 203 break chains and 205 strip gears. I guess its just how hard you like to 'wheel. The t-case in my '03 dodge has held up to four wheel drive lauches at the drag strip with over 750 ft lbs at the wheels. high 15's. with 35 inch tires. its chain driven and aluminum. anything can and will break when you start to play with the big boys.
live by this: "If you want to play, You got to pay"

Not a bad idea. Even easier with the top off the K5!

and if you using a 203 for a doubler remember that just the front half of the 203 is used its the part without the chain so all you are getting is high and low 2 wheel drive part

some new vehicles have carbon fiber drive shafts too, same thing helicopter rotor blades are made of, my 1968 GMC 3/4 ton 4x4 Burb was equipped with a noisy rockwell t-case,( T221?) a tried and true off road veteran that has lugged around my 6200 pound beast for nearly 40 years guess we'll see how many 208's are around after 40 years!


The MASTER has spoken