Np203 Transfer case problem

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

huntemcd79k10

Junior Member
Joined
Feb 2, 2017
Posts
3
Reaction score
0
Location
INDIANA
First Name
Hunter
Truck Year
1979
Truck Model
K10
Engine Size
350
I have a question on a np203 transfer case. What is the shifting pattern first of all. Ive read that the Low is up towards the front but on mine that is high. Right now i have the lever all the way up which that should be loc right? My driveshaft on the front isnt spinning at all. and with it in loc and the hubs on free i can spin the driveshaft by hand. Any help will be appreciated.
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,034
Reaction score
1,829
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
The shift linkage on the NP203 can get out of adjustment, so first adjust the linkage. It make take some work to get it lined up.

If you have locking hubs then you must have a conversion kit installed in your NP203. Lockouts were never used with an unconverted NP203.

Once you think you have the shiter adjusted:
Move the shifter down to the middle position and make sure you find neutral. In this position you can put the truck in drive and it will not move.
- Then shift it down toward the seat one position, which should be High (2WD high on a converted case). Drive it in this position at a steady speed of about 30 mph and listen to the engine.
- Now move the shifter back up and find neutral. From there shift it one position toward the dash to Low (2WD low on a converted case). Drive at the same speed and it should be obvious that the engine is revving much higher.



Bruce
 

huntemcd79k10

Junior Member
Joined
Feb 2, 2017
Posts
3
Reaction score
0
Location
INDIANA
First Name
Hunter
Truck Year
1979
Truck Model
K10
Engine Size
350
The shift linkage on the NP203 can get out of adjustment, so first adjust the linkage. It make take some work to get it lined up.

If you have locking hubs then you must have a conversion kit installed in your NP203. Lockouts were never used with an unconverted NP203.

Once you think you have the shiter adjusted:
Move the shifter down to the middle position and make sure you find neutral. In this position you can put the truck in drive and it will not move.
- Then shift it down toward the seat one position, which should be High (2WD high on a converted case). Drive it in this position at a steady speed of about 30 mph and listen to the engine.
- Now move the shifter back up and find neutral. From there shift it one position toward the dash to Low (2WD low on a converted case). Drive at the same speed and it should be obvious that the engine is revving much higher.



Bruce

On mine high is toward a the front of the truck. I put it all the way up and brought it back one more and it was still high and then one more was neutral. All the way back is low. And I have lockouts with the conversion kit too. I think it may be the chain in the t case. Thanks for your help.
 

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,892
Reaction score
4,036
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
Starting at the dash going towards the seat. Low lock, Low, Nuetral, High, High lock. My '79 truck has a P/T kit with locking hubs. With that, High becomes 2wd High (normal driving) and Low becomes a 2wd Low.
 

huntemcd79k10

Junior Member
Joined
Feb 2, 2017
Posts
3
Reaction score
0
Location
INDIANA
First Name
Hunter
Truck Year
1979
Truck Model
K10
Engine Size
350
Starting at the dash going towards the seat. Low lock, Low, Nuetral, High, High lock. My '79 truck has a P/T kit with locking hubs. With that, High becomes 2wd High (normal driving) and Low becomes a 2wd Low.

Huh. Well mine is the opposite.
 

Big red square

Full Access Member
Joined
Dec 7, 2022
Posts
72
Reaction score
68
Location
El Paso
First Name
Lewis
Truck Year
1977
Truck Model
K10
Engine Size
350
Starting at the dash going towards the seat. Low lock, Low, Nuetral, High, High lock. My '79 truck has a P/T kit with locking hubs. With that, High becomes 2wd High (normal driving) and Low becomes a 2wd Low.
What's the point of 2 low?
 

77 K20

Full Access Member
Joined
Nov 9, 2012
Posts
3,076
Reaction score
3,049
Location
Montana
First Name
Mike
Truck Year
1977
Truck Model
K20 5" lift
Engine Size
HT383 fuel injected
I use it when driving up to old fire lookouts in the summer (or any very steep climb). The roads are typically very rough and steep. 2wd was all that was needed and the speeds typically were 25 mph and under. Using 2wd low reduced lugging the engine climbing then when descending there were multiple gear options for slowing without riding the brakes for miles.
Or you can do a burnout with a old tired engine... :burnout:

full

full


Tires aired down to 12 psi and a rear locker made it possible in 2wd. Found this video of a motorcycle going up it:

xc_hide_links_from_guests_guests_error_hide_media
 
Last edited:

77 K20

Full Access Member
Joined
Nov 9, 2012
Posts
3,076
Reaction score
3,049
Location
Montana
First Name
Mike
Truck Year
1977
Truck Model
K20 5" lift
Engine Size
HT383 fuel injected
I even confuse myself if it has been a few months since I've driven it. I finally ordered shift knobs that have laser engravings showing what they do. Hopefully they are here tomorrow.

full
 

TJ1978

Full Access Member
Joined
Apr 21, 2023
Posts
65
Reaction score
95
Location
arizona
First Name
Tim
Truck Year
1978
Truck Model
K5
Engine Size
350
For the twin stick np203 which I have and is now not available from ORD any longer or temporarily
 

Attachments

  • 92B18C3D-A8C4-4074-AB4E-29B2E8AC273C.png
    92B18C3D-A8C4-4074-AB4E-29B2E8AC273C.png
    316.6 KB · Views: 40

SquareRoot

Full Access Member
Joined
Mar 18, 2017
Posts
3,694
Reaction score
6,682
Location
Arizona
First Name
Mike
Truck Year
85
Truck Model
K20
Engine Size
350
I even confuse myself if it has been a few months since I've driven it. I finally ordered shift knobs that have laser engravings showing what they do. Hopefully they are here tomorrow.

full
Sweet! I love shifting it. The triangulated bracket I made for it is dead solid and the shifter throw is only about and inch in either direction. I was driving it around the house in front wheel drive while I was waiting on my rear shaft.
 

Big red square

Full Access Member
Joined
Dec 7, 2022
Posts
72
Reaction score
68
Location
El Paso
First Name
Lewis
Truck Year
1977
Truck Model
K10
Engine Size
350
I use it when driving up to old fire lookouts in the summer (or any very steep climb). The roads are typically very rough and steep. 2wd was all that was needed and the speeds typically were 25 mph and under. Using 2wd low reduced lugging the engine climbing then when descending there were multiple gear options for slowing without riding the brakes for miles.
Or you can do a burnout with a old tired engine... :burnout:

full

full


Tires aired down to 12 psi and a rear locker made it possible in 2wd. Found this video of a motorcycle going up it:

xc_hide_links_from_guests_guests_error_hide_media
Burnout enough said.
Thanks lol.
 

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,087
Reaction score
23,880
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
For the twin stick np203 which I have and is now not available from ORD any longer or temporarily

Yeah, I hope they bring that kit back. It will be annoying to build my own setup, knowing that a kit used to exist and it was affordable too.
 

TJ1978

Full Access Member
Joined
Apr 21, 2023
Posts
65
Reaction score
95
Location
arizona
First Name
Tim
Truck Year
1978
Truck Model
K5
Engine Size
350
Yeah, I hope they bring that kit back. It will be annoying to build my own setup, knowing that a kit used to exist and it was affordable too.
maybe theyre just be phasing all things 203 out unless you go doubler. But they have the 203 rebuild kit, so who knows.

I have a 205 waiting to go in, but I honestly don't want to hassle with the swap until my 203 dies. Hahahahah. Putting that 203 in solo was not fun at all. I imagine the 205 is slightly easier but still a pain.
 

Latest posts

Forum statistics

Threads
42,065
Posts
908,290
Members
33,542
Latest member
willyg
Top