NP203 to NP208 swap?

[coolpup32]

Easiest route is to pull the 203 and put a part time kit in it. Have it rebuilt and replace the old chain.

Where do you get a new chain for a np203? They're unicorns!!

 

[Kurnacopia]

Where do you get a new chain for a np203? They're unicorns!!

Try looking at these resources:

NP 203 Transfer Case Chain ONLY Made in USA!

www.bjsoffroad.com

Transfer Case NP203 Rebuild Kits drawing and parts list - drivetrain.com

NP203 Transfer Case Rebuild Kits and Parts. As well as free diagnostic troubleshooting help including free illustrated parts drawing!

www.drivetrain.com

You might as the guys at ORD as well, they may be able to help source one. I also like the guys at WFO:

4x4 Custom Truck Parts | Off Road Truck Parts | California Custom Trucks

WFO Concepts offers all your 4x4 custom truck parts needs. Off road truck parts for all years and models available.

www.wfoconcepts.com

email them or call...they are really cool. Ask for Trevor. These guys are serious about 4x4s and are happy to help. Tell them I sent ya.

Good luck my friend!

 

[1979 K10]

There used to be 2 part time kits available to change the np203 from full time to part time. I did the cheaper mile marker kit which you could convert the tcase from full to part time while installed in the truck. Took an hour or two but super easy and straightforward, you just swap a gear which is accessible under a cover on side of case and then install some round needle bearings at the tail shaft making sure you get the correct amount or preload. Kit comes with lockable hubs that replace the full time assembly on corporate 10 bolt front axle. I did this kit and didn’t notice any mpg improvement. I had high hopes but that didn’t help realize any improvement lol

The kit did improve tight turning on pavement (no binding, accelerated tire wear) and most of all front axle unjoints will last forever since you’re not constantly powering the front axle.

NP203 becomes 2WD Loc / 2WD /N/ 2WD Lo / 2WD lo lock if front hubs unlocked.

4WD Loc / 2WD /N/ 2WD Lo / 4WD Lo Loc when front hubs locked and engaged.

NP203 Transfer Case

The full-time four-wheel-drive NP203 transfer case is one of the most standard items found in 70s fullsize 4x4s. Big, heavy, and relatively strong despite its chaindrive, this box can be converted

www.motortrend.com

There was more to that article but only the first page loads for me. There was a better kit offered that requires more work (changing out shaft inside transfer case) and removal of case from truck but that kit has been discontinued for several years.

 

[1979 K10]

Posted in Np203 part time conversion? thread

Np203 part time conversion?

I just got another truck a couple weeks ago and I’m just now getting around to messing with it. It’s a 350/350/np203 truck. It’s the only automatic I own and I got it so the ole lady can drive it some too, but with it being full time 4wd it’s going to get terrible fuel mileage I assume. She’s...

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