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Hey Yall im new to the forum. i just purchased my second 1978 f150 ranger xlt 4x4 with a 400 engine and c6 tranny. the transfer case is this one is different from my first truck's. this truck has auto hubs and the transfer case has hi, hi lock, N, lo, and lo lock. i had the shifter in hi and punched the gas and the rear tires didnt spin any, the truck just took off in 4x4. i dont know how this works and i want to.
Those are not auto locking hubs. Those hubs are always engaged. You have a NP203 transfer case which is a full time 4wd system. The "Loc" selection allows you to lock up the bias (output) from front to rear for maximum tractioin off road. This is not to be confused with the differentials, or lockers or similar traction devices in the axles themselves. SImply allows the front and rear driveshafts to obtain equal torque.
When you are in either hi ir low, you are still in 4wd, just that now the center differential(transfer case mounted) is able to differentiate speed differences betweem the front axle and rear axle for street driving. This prevents the truck from chunking, or hopping around turns typical with driving part time cases on the highway. The front axle and rear axles have to travel at different speeds during a turn, and the 203 allows this to be possible while still in 4wd.
Part time kits are available, and a NP 205 is a fairly easy replacement.
Only after you convert the case to a part time unit, or install a part time case. By installing locking hubs in it and leaving the case a full time unit, it will not go anywhere unless you are in one of the "LOC" selections. By leaving it in the loc position, it will not allow the front and rear wheels to travel at different speeds, and you will not be able to drive it on the street.
Note that a full time 4wd does not have a 2wd selection. That is what makes it "full time".
oh okay that makes sense. i dont think i like that t-case. i will probably put a normal 2hi, 4hi, 4lo t-case in it. when i do that can i then put locking hubs on it? i guess what im asking is can it be done with the axle thats in the truck? and also is that np 203 a gear to gear t-case? and whats the strength of that one vs. a part time t-case? does one hold up better than the other?
Last edited by Fordman400 4x4; Oct 1, 2007 at 08:18 PM.
I have had pretty good luck with 203 cases. They get bad criticizm because it uses a chain, and not all gears, but all in all they are pretty strong. I mean if you are not gonna run crazy big tires, it will hold up. Now the 205 is a super reliable and desireable unit. It is the prefered case due to its all gear design. Simple to find and a real workhorse.
As far as your front axle, yes it will accomodate locking hubs once you address the 2wd issue.
Keep in mind that you will need to make some other changes to accomodate a 205.
crossmembers are different, transfer case adapter and mount, shifter linkage, lengthen rear drive shaft, shorten the front.
Not a terribly simple job, but is nice in the end.
well the guy i bought the truck from has a 79 with the np205 t-case and he wants my 203. maybe we could swap everything necessary. but his is a short bed so ill still have to get a rear drive shaft.