My truck (from my other thread) has a 400/4spd/np205 from another truck from one of many previous owners and I'm trying to figure out what I have. The front hubs have no wires and no manual locking mechanism so I'm thinking maybe it's the original full time front end? Is this possible, would the drive shaft have worked if this were the case.
2wd works fine as does 4wd so I'm 99 percent positive that the t- case is a 205. Either way it's not a 203 as it doesn't have the shifter box and it has 2wd 4 lo and 4 hi. I always assumed that the hubs were automatic but I've been told that they weren't an option back then.

 

 

So, aside from the hubs , the 203 and 205 equipped trucks have the same axles. I wasnt 100 % sure but that's what I thought. I only drove it during winter or off road so I'll probably just leave them until they break. Thanks

 

 

I know guys who locked the hubs and left them locked ...

 

The turning radius is fine. There is no popping or hopping. And the engine was built with no thought for mileage anyway. So I'll leave them. I only got concerned because I already have all new brake lines, calipers, rotors, seals etc in the basement and then realized that nothing matched. Like I said in the other thread It's a frankentruck, I knew the engine wasn't original because they wrote the mileage over the sun visor. I looked up the disassembly of the hub to better prepare and realized that automatics werent even available so I assumed they were always locked

and yes we have an 02 v10 sd that as far as I know hasn't been unlocked since we bought it used. As a farm truck they go in and out of 4wd so they just stay locked. And 8-12 mpg isn't going to improve enough to constantly bend down or wade mud/ snow to lock in. Thanks for the info

 

I usually lock mine in the first real snow of the season, and unlock them after the snow melts in the spring. In Wyoming that is usually around mid Oct. to sometime in May.
I have had several mechanics tell me there is less wear on the front drive components with the hubs locked in than if they are unlocked all the time. You might get a bit better mileage with them unlocked, but it certainly don't hurt them to be locked in. Just make sure you have the transfer case in 2 high while on dry roads.

 

Wel i was born 7 years after my truck so by the time I was driving my parents 4wd it had automatic hubs. It was a 94 Mitsubishi mighty max/ dodge d50. So when I later bought the truck I assumed that it was auto. I never saw out of 20 or more old fords we had on the farm, a np203 equipped truck. (Most were 2wd though). I've still to this day not seen one in a truck. But because of reading on here a lot I had researched them some. We did have a blazer in the 80s that I barely remember but have been told was full time 4wd. So I'm guessing it was a 203.