Well im not an expert on xfer cases, its just that Ive dealt with a few 203s and 205s..
Ive seen locking hubs put on a full time truck with no other mods a few times.. the main reasons are probably:
a) they think it will reduce tire/driveline wear
b) they think it will improve gas mileage
c) they think thats all it takes to convert to part time
d) they already have problems with worn frontend stuff
in reality it doesnt make a diff. on your gas bill.. I could see it reducing wear on the two front tires, but when I had a full time truck, the tires wore so perfectly and even, it was almost a benefit. I never noticed any harsh handling characteristics.
let me ask you this: when your hubs are in the FREE position, you have to drive in hi LOC or lo LOC right? (shifter all the way forward or all the way back) If not, then you DO have the part time kit installed. if the hubs are unlocked, and you're just in regular HI or LO range, then the differential in the 203 case thinks you are hanging off the edge of a cliff, or something. in other words, the front end has zero traction, and its giving all power to the front end, and you go nowhere... just like an open differential in a rear end. the tire with the least traction spins every time.
so...... in order for you to drive, with the hubs unlocked, you have to have the xfer case in LOC mode, which spins the front drive train ANYWAYS.. the only difference is the power stops at the end of the axles, instead of being transfered to the ground.. I dont see the point really. the full time is safer.
if you DO have the part time kit installed, it is normal for the front end to spin while you're driving.. some more than others.. its just grabbing for whatever reason.. kind of like how if you jack up a car and its in neutral the wheels will still spin while the engine is running.
well hope i didnt confuse you more than anything.. anyone have anything to add?
ps- the reason I like the 203 case so much is because 1) Ive seen zero 203s fail under abuse, and at least one 205 fail. Its not an issue of strength.. they are probably the two strongest stock cases you can use. and 2) the 203 shifts so much nicer!! it actually clicks between gears... maybe ive only shifted old worn out 205s or something but its basically a matter of trial and error, and luck when trying to find 4, 4 lo, etc.
mike reeh