The f250 I just bought will only pull itself when I he front hubs are locked in. I assume I going to have to rebuild the transfer case. Any ideas?

 

Don't assume just yet. Maybe, but first things first anyway.
As in, cheaper is better in the beginning!

Since 203 trucks did not come with locking hubs for a reason, it's very possible yours is doing exactly what it's supposed to do.

Do you have a rear driveshaft?
Since you just bought it, do you know if the full-time 203 was ever converted to a part-time setup? Since it's got locking hubs, the chances of that are pretty good.
Or at least someone got part of the way.

When the transfer case is working as expected, if you unlock the hubs you need to put it into Loc to drive it. Otherwise the center differential (inside the t-case) simply puts all the power to the end with the least traction. In this case it's the front driveshaft because the hubs are free.

So for now leave the hubs locked and wait for experts in 203's to chime in. There might be some external clues in to what, if anything, was installed in the t-case.

Good luck. Might be just that someone installed hubs to save gas and didn't realize you had to have the front end locked/slugged at all times.
Wasn't you by any chance, was it?

Paul

 

Oh, and while you're waiting on expert advice (mine's just semi-expert through the University of Osmosis) try googling "mile marker" or "part time conversions" or something along those lines to see what comes up.
Maybe add quotations and this website after the question phrase to make sure the answers you get are about threads started here.

Paul

 

It has the mile marker front hubs. I'm not use to the older 4 wheelers. My 79 had locking hubs. I thought the hubs had to be unlocked if you wanted 2 wheel only.

 

Has a rear driveshaft. Some one has installed mile marker hubs.

 

Any of the Fords with the NP205 gear-driven box would have had locking hubs (at least as an option) to disengage the front drive system if it wasn't in use. But any of the NP203 trucks (all of them in fact, whether GM, Ford or Dodge) came with drive slugs and chrome caps.
It was simply an early version of an all-wheel-drive setup. Same concept with an actual differential inside the transfer case to put the power to either front or rear, but not to the other. If you disengaged that for some reason, or lost a front driveshaft, it simply slipped and you went nowhere.

The conversion kits were of two designs, but both essentially locked up the center differential so that you had a normal 2wd/4wd setup. To take advantage of that, you installed locking hubs in the front.
If you install and unlock the hubs, you simply spin the front driveshaft and go nowhere. Just like if you put one tire in the mud and one tire on the pavement in an open differential.

What you're doing with the hubs locked is running the truck in it's normal setting. To get a full 2wd effect, you have to convert the transfer case to a locked state.
The cheap kits (in the '80's they were about $40-50 bucks) were simple, easy to install, but were known for wearing out the internal parts.
The less commonly sold (due to it's over $200 price point even back then!) full shaft replacement kit was more reliable in the long run (50k miles or more) in the full size trucks.
So for now just roll with the lockouts engaged.

Another little tidbit from the wayback machine (if it's working properly that is) is that with GM and Dodge trucks, if you bought one with an automatic transmission, you got the full-time 203 transfer case whether you wanted it or not. If you bought it with the manual trans, you got the part-time 205. Again, whether you wanted it or not.
With Ford, you could order your trans and t-case in either flavor.

Another thing that these boxes were known for is stretching chains. Nothing wrong with a t-case being chain driven. Just that this design, or the early chains, were just not meant for high mileage applications. Usually by 75 to 100 thousand miles, you had to replace the chain. If you were harder on your equipment, it wasn't unheard of for them to be worn enough to replace by 40k miles.
There were tensioner kits for awhile, but I never saw one. Most just replaced the $60 chain.

Good luck with yours. So far it sounds like it's acting normal.
Oh, and is your shifter **** showing the part-time pattern, or the full-time pattern showing the Low, Low-Loc, High, High-Loc wording?

Paul