How to tell if my NP203 has been converted to part time?

[Silver Square]

Here's the crossmembers.

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[AuroraGirl]

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Here's some better pix of the front and closeups of the side right where the driveshaft comes out the front of the case. Yeah, I know the tire is low in that pic. I took it when I was looking at the truck before I bought it. I pumped it up before I drove it home. Not sure what's going on with the mount, it looks factory.

you appear to have the assembly, its the thing the driveshaft is bolted into on the front output. i think. also i think youre missing a torque rod from your t case to your th350

 

[Silver Square]

What is the torque rod, and where should it be?

 

[AuroraGirl]

What is the torque rod, and where should it be?

i may be wrong but it should run to the flat area on the side of the t case

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And then to the bellhousing of the trans. but it doesnt appear to have threads there. is there dirt shoved into threads there or is it solid metal?

 

[bucket]

i may be wrong but it should run to the flat area on the side of the t case

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And then to the bellhousing of the trans. but it doesnt appear to have threads there. is there dirt shoved into threads there or is it solid metal?

Many of the 203 trucks didn't have the support rod.

 

[Silver Square]

I don't see any threaded holes. Is the area in the red box where you're talking about?

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[Old Guy Bill]

While you’re under there check the shifter linkages…

 

[75gmck25]

I don’t think my ‘75 with TH350 and NP203 has a support rod. I’d have to crawl under there to see if there is a threaded hole for the rod.

 

[DrvnDrvr]

NP 203 with support rod and th400
No transfer box skid plate and a seriously MickeyMoused parking brake cable.

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[Dooley]

Well, I found a stock 203 case not too far away for $100. Figure my best bet is to just get the stock one and have it rebuilt so I know it will operate as it should and sell this problem to somebody more willing to deal with modified stuff.

Is the 1977 K10/K15 NP203 the 2 or 2.5" chain? I see both options, but none of the retailers tell me which one I need for this application.

I'm guessing if I just lock the hubs and leave them that way, the truck will operate properly with a stock 203 case? Or would I need to remove the locking hubs all together?

Can I use limited slip diffs in the front and rear with a stock 203? Think I remember reading somehwre that they don't play nice together, but now I'm finding conflicting info.

Thanks.

The early 203 cases had the 2.5 chain. When they went to the 2" chain they changed the pitch on the chain/gears. This prevented much of the chain slippage on the higher mile/worn transfer cases.
Change happened during the 1978 model year. I put 200,000 on a part timed 1979 case with zero problems.

 

[Raybo135]

the hubs should work, but i suspect the stub ends of the original axles are technially stronger than the hubs as they have less parts and dont have mechanisms for sliding etc, but if your hubs are in good shape i cant see why it wouldnt work.

Do you still have the differential or cv unit to the front that balances front to rear to allow you to get turns. if the person "deleted" that , im not sure if you can, it would maybe explain grinding and not wanting to work right

That is not an extra support, that is a factory option skid plate to protect the T-case while off roading and rock climbing. It comes with a protective plate under the gas tank also. It was about a $125 option from the factory.