Rear wheel drive with NP-203?

[Brysonsproject]

1978 Chevy K20, TH400, NP-203(all time 4wd), all time 4wd hubs. I'm wondering if I can simply install locking hubs and make this rwd. I asked someone and he said that wouldn't work because the t-case would just send all the power to the end with least resistance, so when I unlock the hubs, it'll just spin the front driveshaft and axle, but the truck won't move. I thought of just keeping the t-case in hi-lock, so it spins the front and rear at the same speed when I unlock the hubs and it seems like that would work but I don't know if its good to run the truck like that all the time. (with that option, I would put the t-case back in high (not locked) when I lock the hubs again and want it in regular 4wd.) Let me know if all that made sense, thanks!

 

[Rickf]

As a test, remove the front driveshaft and see if the truck moves. If it doesn't, go to plan "B".

 

[legopnuematic]

If you search around you can find threads on doing the part time conversion for an NP203.
Here is one

Manual front hubs and a part time kit in the transfer case will give you rwd.

With only adding front manual hubs its correct that the truck should only move in ”Loc” as the np203 being a full time transfer case, is like an open differential with spider gears to allow power to go to one output or the other, or equally between the two under different conditions.

 

[GTX63]

As a test, remove the front driveshaft and see if the truck moves. If it doesn't, go to plan "B".

Yes a 203 will function without the front shaft.

 

[bucket]

1978 Chevy K20, TH400, NP-203(all time 4wd), all time 4wd hubs. I'm wondering if I can simply install locking hubs and make this rwd. I asked someone and he said that wouldn't work because the t-case would just send all the power to the end with least resistance, so when I unlock the hubs, it'll just spin the front driveshaft and axle, but the truck won't move. I thought of just keeping the t-case in hi-lock, so it spins the front and rear at the same speed when I unlock the hubs and it seems like that would work but I don't know if its good to run the truck like that all the time. (with that option, I would put the t-case back in high (not locked) when I lock the hubs again and want it in regular 4wd.) Let me know if all that made sense, thanks!

Yes, you can install front locking hubs and simply run the truck in High Loc, it won't hurt anything. MPG savings will be negligible but you should see slightly less wear and tear on front tires and u-joints.

 

[AuroraGirl]

Yes, you can install front locking hubs and simply run the truck in High Loc, it won't hurt anything. MPG savings will be negligible but you should see slightly less wear and tear on front tires and u-joints.

which, to be honest, may very well be worth it depending on how many miles you get out of the front end on them lol

 

[ali_c20]

Mpg on a brick shaped truck is never going to be great. The rwd conversion is fun to drive and for donuts. You could swap a np205 or np208, both have rwd.

 

[sidschev]

i had a dodge that had the 203 case. it was my hot rod .. it ran well with out the front shaft. it kept breaking drive shafts and finally the rear end broke. man i miss that truck talk about fast and if the rears tire hooked she would lift the front end... drove it several year with out the front drive shaft never a problem...

 

[Copymutt]

There’s just something about chain drive that seems Neanderthal! I like it! I use it!

 

[74Blaze]

My old NP203 had the conversion, my new one does not. I like it better with the full-time. It just feels right.