Transfer case

[79scottsdale400]

How can I tell which np transfer case I have? So far I saw np and lo 2 on it. It's hard to see anything. But I'll get some pictures. Also I have locking hubs. Don't know the shift pattern there's nothing telling it either

 

[nvrenuf]

Do you know the shift pattern? Does it have 4 positions or 5? Cast iron shell or aluminum.

If you're looking at your '79, my money says np203.

 

[79scottsdale400]

I'll find out after work if it's 4 or 5 positions. If it is 203 would swapping for a 205 be a better idea or just keep the 203 and rebuild it?

 

[79scottsdale400]

If it is full time wouldn't the front drive shaft be locked in cause I can spin it all the way

 

[nvrenuf]

Does the truck have locking hubs? If so and a 203 it could have previously been converted to part time (front shaft would turn freely).

IMO, everyone needs a 205 but if it's in good shape with a tight chain the 203 is a strong and durable case. The shifter is junk but if that's the only issue you can twin stick it fairly easily.

 

[marks86]

If it is full time wouldn't the front drive shaft be locked in cause I can spin it all the way

the driveshaft wont be locked until you pull the fourwheel drive lever

with a np203 with locked hubs the axles/ ring gear spin all the time and the pinion just sits there until you pull the lever(just think the pinion is connected right to the drive shalf)

 

[nvrenuf]

the driveshaft wont be locked until you pull the fourwheel drive lever

with a np203 with locked hubs the axles/ ring gear spin all the time and the pinion just sits there until you pull the lever(just think the pinion is connected right to the drive shalf)

This is NOT how a ring and pinion or open diff work. The pinion touches the ring gear therefore if the ring moves, the pinion moves.

 

[marks86]

This is NOT how a ring and pinion or open diff work. The pinion touches the ring gear therefore if the ring moves, the pinion moves.

ha I guess you got me there, but the pinion does not have power to it until the lever is pulled is this correct

 

[79scottsdale400]

If it's converted to part time does that mean it shifts like a regular transfer case. That being 2hi 4hi n 4low?

Also. Twin stick? What would that do. How would it function?

I'm trying to figure all this out because it's leaking gear oil and I wanna drop it and rebuild it.

 

[nvrenuf]

If it's converted to part time does that mean it shifts like a regular transfer case. That being 2hi 4hi n 4low?

Also. Twin stick? What would that do. How would it function?

I'm trying to figure all this out because it's leaking gear oil and I wanna drop it and rebuild it.

When converted to part time, the "Loc" positions are 4wd and the others are 2wd.

The 203 shifter are notorious for wearing out and not engaging a selection completely causing it to pop out of gear under stress. A twin stick kit eliminates the factory shifter altogether replacing it with 2 independent sticks (1 for 2/4wd, 1 for high/low range). Off Road Design sells a kit.

 

[79scottsdale400]

Ok. It has 5 shifter positions. Locking hubs. Did find numbers on the case as well. Looks like a 203 from pictures I have seen

 

[79scottsdale400]

Looks like this

 

[79scottsdale400]

Only that hose thing is on the right side. I'll see of I can upload one of mine. Everytime I try it says the file is to big

 

[MrMarty51]

If You are going to convert to a 205, be sure and get the T-Case and the adapter for the same transmission that You currently have.
NP205s from a TH400 is really tough to come by, and, the pieces to convert one from a TH350 or from a manual trans. to the TH400 is very very expensive.
I currently have a 205 and the adapter pieces for a TH350 but I just do`nt want to change from a TH400 to the TH350 to get a 205 case into My 79.
My NP203 has the low range slider and gears wore out, can not even hold it into low.
Works real good other wise.
I built My own twin stick shifter for the NP203 too, I like it, gives it this sort of a K~00~L factor.