Transfer Case Info for OEM Squarebodies

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.

tiredtiretodd

Full Access Member
Joined
Jul 9, 2014
Posts
170
Reaction score
20
Location
NORCAL
First Name
Todd
Truck Year
75
Truck Model
K 25
Engine Size
350
After reading a couple other threads I've come to find out that my front Dana 44 has locking hubs....(I went outside and looked.) That however, from what I've read, doesn't mean that it's part time. Am I right? Attached are a couple few photo's. What T case is this? Also Why does one of my locking hubs say Spicer and one says Ford? Either way I'll be changing those to Warn locks soon!
 

Attachments

  • 009.jpg
    009.jpg
    95.9 KB · Views: 757
  • 010.jpg
    010.jpg
    96.2 KB · Views: 691
  • 012.jpg
    012.jpg
    96.3 KB · Views: 662
Last edited:

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,008
Reaction score
8,977
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Does look like an NP203 to me. Someone may have put a part time kit in it if you're able to run with the front hubs unlocked. There is nothing wrong with hose hubs. Both are Spicer OEM hubs. Just that Ford wanted to take credit for the Spicer hub so they had their name put on it instead of Spicer.
 

tiredtiretodd

Full Access Member
Joined
Jul 9, 2014
Posts
170
Reaction score
20
Location
NORCAL
First Name
Todd
Truck Year
75
Truck Model
K 25
Engine Size
350
Does look like an NP203 to me. Someone may have put a part time kit in it if you're able to run with the front hubs unlocked. There is nothing wrong with hose hubs. Both are Spicer OEM hubs. Just that Ford wanted to take credit for the Spicer hub so they had their name put on it instead of Spicer.

I'll probably run the 203 for a while then later put a 205. I don't drive it yet but I do know that the previous owner locked the hubs to try to put the truck in a trailer when I went to buy it. I ended up having it towed.
 
Last edited:

tiredtiretodd

Full Access Member
Joined
Jul 9, 2014
Posts
170
Reaction score
20
Location
NORCAL
First Name
Todd
Truck Year
75
Truck Model
K 25
Engine Size
350
that is most definitely a np203 because it doesn't have that little plate with three bolts
like this np205
You must be registered for see images

upload png

Yea, I looked for images so I could determine what the little plate w/ three bolts looked like but I finally ended up finding a picture of a 203 that matched mine. I do appreciate the replies because I am trying to still figure out what I do have in this truck.
 

firebane

Full Access Member
Joined
Jul 10, 2014
Posts
1,732
Reaction score
29
Location
Calgary, AB
First Name
Curtis
Truck Year
1974
Truck Model
K10
Engine Size
350
Yea, I looked for images so I could determine what the little plate w/ three bolts looked like but I finally ended up finding a picture of a 203 that matched mine. I do appreciate the replies because I am trying to still figure out what I do have in this truck.

If you have the NP203 you most likely have a TH350 transmission as well.
 

Dmaxroger66

Junior Member
Joined
Aug 30, 2016
Posts
1
Reaction score
0
Location
Texas
First Name
Roger
Truck Year
86
Truck Model
K1500
Engine Size
305
I'm having a problem where the truck disengages in drive and won't engage in any other gear. (Sounds like it was thrown in reverse by accident) when attempting to shift to P. Only way it engages back is by going into 4 Lo and driving forward a bit. Then I can go into 2hi again. Eventually it will grind but everything will be fine when things cool off. Mechanic says I need total replacement.
 

Mike Koolhof

Junior Member
Joined
Jul 29, 2018
Posts
9
Reaction score
0
Location
Virginia
First Name
Mike
Truck Year
1977
Truck Model
K15
Engine Size
350
Is there a foolproof way to identify the transfer case? I have a 1977 K15 Sierra Grande full time 4WD with a high and low lock, which I assume is on the front only. It has a TH350
 

HotRodPC

Administrator
Staff member
Admin
Joined
Aug 29, 2010
Posts
47,008
Reaction score
8,977
Location
OKC, OK
First Name
HotRod
Truck Year
85 K20 LWB
Truck Model
Silverado
Engine Size
454 - Turbo 400 - 3.73
Is there a foolproof way to identify the transfer case? I have a 1977 K15 Sierra Grande full time 4WD with a high and low lock, which I assume is on the front only. It has a TH350

Don't Assume. It is NOT the front only. The easiest way to understand the NP203 full time 4wd is to think of the transfer case as just like a rear end differential. The wheel with less traction is always the drive wheel. Now consider your front axle as your right wheel, and your back axle as your left wheel. It's a differential. When you lock it up, then it's like a locker in a rear end where both wheels are driven and apply power.

So if NOT in LOCK position. Your front axle might be powering the truck, or it might be the rear axle power the truck. When you go into LOCK, then BOTH axles are powering the truck.

Yes, it's 4wd meaning, any 1 of the 4 wheels can be powering the truck unless you have lockers, then it's either the front 2 wheels or the rear 2 wheels. If you LOCK it up, and have lockers in the axles, then it's all 4 wheels powering the truck.

Hope that helps in understanding the NP203.

The Part time units like the NP205 and NP208 are powering just the rear axle when in 2wd. In 4wd, it's powering both front and rear axles.
 
Last edited:

Gilmore

Full Access Member
Joined
May 1, 2019
Posts
66
Reaction score
37
Location
Eureka
First Name
Christopher
Truck Year
1984
Truck Model
K10
Engine Size
6.2L Diesel
I hate to be the guy to ask the dumb question but is there a number on the case anywhere that will tell you which one I have? My truck is an 84 1/2 ton originally a diesel 6.2 L with a 700R4 trans.
 

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
2,837
Reaction score
6,356
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
I hate to be the guy to ask the dumb question but is there a number on the case anywhere that will tell you which one I have? My truck is an 84 1/2 ton originally a diesel 6.2 L with a 700R4 trans.
There are no dumb questions, only dumb answers. My dumb answer is your truck most likely has a New Process Gear transfer case. It would have come from the factory with a tag like this:

You must be registered for see images attach

If the truck spent any time in the salt belt, the tag probably melted away.

Post a picture of the transfer case, someone will tell you what it is.
 

Gilmore

Full Access Member
Joined
May 1, 2019
Posts
66
Reaction score
37
Location
Eureka
First Name
Christopher
Truck Year
1984
Truck Model
K10
Engine Size
6.2L Diesel
It looks like it may be a 208. Is there anything else I need to know that you can tell by the photo?
 

Attachments

  • ECC90393-3B5C-4FDB-BA48-55F712D84822.jpeg
    ECC90393-3B5C-4FDB-BA48-55F712D84822.jpeg
    240.7 KB · Views: 35
  • FF765D9E-AAC6-4A13-BE78-FD83ABAF0E1E.jpeg
    FF765D9E-AAC6-4A13-BE78-FD83ABAF0E1E.jpeg
    237.9 KB · Views: 34

Gilmore

Full Access Member
Joined
May 1, 2019
Posts
66
Reaction score
37
Location
Eureka
First Name
Christopher
Truck Year
1984
Truck Model
K10
Engine Size
6.2L Diesel
There are no dumb questions, only dumb answers. My dumb answer is your truck most likely has a New Process Gear transfer case. It would have come from the factory with a tag like this:

You must be registered for see images attach

If the truck spent any time in the salt belt, the tag probably melted away.

Post a picture of the transfer case, someone will tell you what it is.
So if I read this right I have a 208c transfer case with a 261 gear ratio. Correct?
 

rusted nuts

Full Access Member
Joined
Mar 5, 2023
Posts
809
Reaction score
1,416
Location
Pa.
First Name
Jeffrey
Truck Year
1979
Truck Model
k20
Engine Size
4cly diesel
Does look like an NP203 to me. Someone may have put a part time kit in it if you're able to run with the front hubs unlocked. There is nothing wrong with hose hubs. Both are Spicer OEM hubs. Just that Ford wanted to take credit for the Spicer hub so they had their name put on it instead of Spicer.
And very hard to fine round here too.
 

Attachments

  • cat in winnder 001.JPG
    cat in winnder 001.JPG
    93 KB · Views: 18

Latest posts

Forum statistics

Threads
41,857
Posts
903,628
Members
33,370
Latest member
mitchell1128
Top