The NP208 is a part time Tcase.  What makes you think its full time?

 

I have a  np 203  that I'm tryin to  change  to part time

 

Only a few companies made the kits. Milemarker was the biggest ( and likely made them for the others).

Do a search on here, and you will find lots of reasons not to do the conversion. Mainly, you will never recover the cost, and 2 its not great for the life on the case.

 

I do have a 208 but I've heard that it won't work on my 435 4speed  cause it has the 203 on it something bout the splines are different an the length is different on the output shaft

 

That's correct. I would just run the 203 the way it is. There is lots of advantages to the full time.

 

I ran a milemarker part time kit in my 203 before switching to the 203/205 doubler. 

It definitely made the truck easier to drive, and more fun to drive and puts less wear and tear on the drivetrain in the front.

If you are hard on the truck it can cause some problems in the 203.  When I took mine apart, the center differential in the t-case had started to develop a crack in it, but I was wheeling mine pretty hard with 36's on it.

I did also have one drive to reverse drop at about 55mph once, so that may have done it as well, it cracked three of the ears on the flexplate when it happened.

 

That's correct. I would just run the 203 the way it is. There is lots of advantages to the full time.

+1 i like the 203. and i like the 44fbj. combo always worked well for me.

 

My buddy has a part-time conversion kit in his 76 K10, I know it's chevy, but same t-case pretty much.  He normally will drive about 100 miles or so and will occasionally just throw it in lock mode to lubricate the chain and front output.  He has manual lockouts on his front axle.  I wish my 203 was part-time, can't say how many times the full-time (unlocked) won't go up a hill or through something he can make in 2wd just because one of my front tires will start to spin.  But I'm already in the works to swapping the 203 for a 208, so that's my fix for it. 

 

+1 i like the 203. and i like the 44fbj. combo always worked well for me.

I don't hate, but nor do I like the D44FBJ axle. If I get the time, all my 4x4's will be full time by the end of this summer. The nice thing about the 435/203 combo, is with practice you can double clutch the transfer from hi to lo, and back while moving. effectively Giving you 6 forward gears. do 1 to 4 in lo, drop the maijn back to 3rd, and transfer to hi, then to 4. The higher lo ratio of the 208, and 241 make it much harder since you have to drop the RPM's by 2/3, before doing the double clutch, and transfer shift, much trickier to do without loosing too much ground speed. And you have to drop the main tranny to 2nd.

But thats me, I ride all my trucks hard, and put them away wet.

My buddy has a part-time conversion kit in his 76 K10, I know it's chevy, but same t-case pretty much. He normally will drive about 100 miles or so and will occasionally just throw it in lock mode to lubricate the chain and front output. He has manual lockouts on his front axle. I wish my 203 was part-time, can't say how many times the full-time (unlocked) won't go up a hill or through something he can make in 2wd just because one of my front tires will start to spin. But I'm already in the works to swapping the 203 for a 208, so that's my fix for it.

With the 203, you just reach down, and grab hi-loc. No need to stop. Ive gone years with out ever using either hi-loc, or low-loc.

If a K10, can make it up a hill in 2wd, that a full time cannot, there is more to the story. Lick a limited slip, better treads, weight, something. Best thing chebbey made, was the 14 bolt & Gov loc.

 

I'm a fan of full-time 4x4, so long as its robust. Are the 203's differential components available new anymore?

Another possibility for fulltime is the NP242 tcase. Basically a NP241 with an extra 4hi-fulltime mode. Mainly used in Jeeps, but also saw use in V8 Durangos and Hummers. They are driver-side drop, but rumor has it you can put one together for passenger drop using a Dodge 241 housing.

Best thing chebbey made, was the 14 bolt & Gov loc.

14bolt FF - absolutely. However, myself and many others will attest the factory gov-lok is fragile and unreliable.

 

I'm a fan of full-time 4x4, so long as its robust. Are the 203's differential components available new anymore?

Another possibility for fulltime is the NP242 tcase. Basically a NP241 with an extra 4hi-fulltime mode. Mainly used in Jeeps, but also saw use in V8 Durangos and Hummers. They are driver-side drop, but rumor has it you can put one together for passenger drop using a Dodge 241 housing.

14bolt FF - absolutely. However, myself and many others will attest the factory gov-lok is fragile and unreliable.

idk, but i remember replacing the diff in my 203....must been around 90-91. don't remember where i got it but i do remember it was a very beefy machined part not at all like the stock carrier.

 

The 203, was rated the same as the 205. Used in all Dodge trucks from the 1/2 ton, to 1 ton, and even behind the 440.

Some of the military surplus dealers still have some Depot rebuilds available, but you will pay.

Parts, I know all the bearings, and seals, and chain are still available. Other parts, I do not know.

The part time kit, especially the one with the 4 1/4 gear sections, place lots of crazy stress to the differential. In the stock form, the stresses are divided between the front and rear axle. Or in loc mode, bypasses the differential all together.

14bolt FF - absolutely. However, myself and many others will attest the factory gov-lok is fragile and unreliable.

True, you need to drive it like you own it.

.

 

If a K10, can make it up a hill in 2wd, that a full time cannot, there is more to the story. Lick a limited slip, better treads, weight, something. Best thing chebbey made, was the 14 bolt & Gov loc.

Hate to tell ya, but it's because the 203 can and will allow one tire to spin, like the front left or right tire and it's not hard to do going up a hill. Now, when it's in LOC mode, it does fine since it's in 4x4 mode. But I have never cared for and never will care for the full-time 4x4 while off road. I'm ready to pull that damn 203 and put the 208 I have laying around in it. At least then my truck will do donuts again.

 

Hate to tell ya, but it's because the 203 can and will allow one tire to spin, like the front left or right tire and it's not hard to do going up a hill. Now, when it's in LOC mode, it does fine since it's in 4x4 mode. But I have never cared for and never will care for the full-time 4x4 while off road. I'm ready to pull that damn 203 and put the 208 I have laying around in it. At least then my truck will do donuts again.

Yep, the 203 has power to all four wheels, and the one with the least traction, can and will spin. The K10 in 2wd, will have power to both rear tires, and the one with the least traction, can and will spin.

Least of 4 Least of 2.

To bad you are not closer, I would trade you a 208 for a 203 anyday.

 

Yep, the 203 has power to all four wheels, and the one with the least traction, can and will spin. The K10 in 2wd, will have power to both rear tires, and the one with the least traction, can and will spin.

Least of 4 Least of 2.

^ exactly.

There's a time and place for fulltime (AWD)... offroading, for the most part, isn't it.

 

Yep, the 203 has power to all four wheels, and the one with the least traction, can and will spin. The K10 in 2wd, will have power to both rear tires, and the one with the least traction, can and will spin.

Least of 4 Least of 2.

To bad you are not closer, I would trade you a 208 for a 203 anyday.

I have 3 laying around, just have to swap the transmission and t-case when I finally decide to do it. The funny thing is, both trucks, my RC and his K10 have limited slip rears. But my front tire normally ends up spinning and loses traction while both his rears will pull and make it through more off road. After I pull the 203, I'll sell that one and the spare I have. I've already had one 203 go bad on me, and I'm thinking the one in my truck is starting to show the same signs. The front output shaft starts binding up, either chain or bearing related.

 

Some of the military surplus dealers still have some Depot rebuilds available, but you will pay.

Years ago I bought a surplus "rebuilt" 203 from Boyce Equipment. The chain was so loose it would pop on a small hill. I know 3 other people that bought them, all of the chains were stretched, one of them was even exchanged first because it had so much water in it.

If they still sold them I wouldn't recommend them.

 

Years ago I bought a surplus "rebuilt" 203 from Boyce Equipment. The chain was so loose it would pop on a small hill. I know 3 other people that bought them, all of the chains were stretched, one of them was even exchanged first because it had so much water in it.

If they still sold them I wouldn't recommend them.

Ouch!. Wonder if they were even Ex military. I think it was miller surplus back in Pa, that steam cleaned and painted the outside of parts, and sold them as new or rebuilt. Would not have figured Saturn as doing that, but then again, many junkyards and used car dealers work the same way.