'78 blazer question

[78K5]

aparently it was somewhat commonplace for the trucks/blazers around then, that came as all time 4x4, to have the shifter/hubs added, and modify the transfer case (or whatever it is they would do)
so what all does this involve? how do i know what transfer case i've got, etc etc

[K5Chris]

if you have full time 4wd, you have an np203.

to convert, you have to get a kit for the transfer case, as well as convert your hubs. ck5.com has alot more info on it.......

[78K5]

damn, youre just the answer to all my questions here ;) i appreciate it though.

it was full time, but it has been converted. how is the np203? sh*t? obviously ive still got alot to learn, but im trying :)

[ayev8r]

I would trash the NP203 if you can afford the swap. It is a chain driven xfer case. A heavy big ole p.o.s.. Get a 205 or similar, as they are gear driven.I had a 75 Blazer with that case and did the part-time swap, the xfer case doesn't like it over a period of time. Also check out your front end parts real good, they should be good and worn out, that is what happens when they are full time.

[K5Chris]

get a 205, but dont trash the 203.... keep the low range box, and bolt it between the tranny and the 205..... DOUBLER baby. :thumbup:

[78K5]

man, this all a foreign language to me..

ayev8r, front end parts..such as what? ive looked the whole truck over pretty well and everything seems to be in pretty damn good shape. the guy who i got it from just replaced all the u-joints and what not, but like i said..im still learning

[Greenbuggy]

man, this all a foreign language to me..

ayev8r, front end parts..such as what? ive looked the whole truck over pretty well and everything seems to be in pretty damn good shape. the guy who i got it from just replaced all the u-joints and what not, but like i said..im still learning

Running full time 4WD on a surface that doesn't give (such as pavement or well packed dirt roads) is much harder on everything because there isn't any give. In the mud, if there is a small difference in ratio between front and rear axles, it won't matter because there will be more than enough slippage to compensate. However, on a hundred thousand miles of pavement, there isn't nearly as much give, so things like the front gears, hubs, u-joints/knuckles and tires all wear much faster in full time 4WD than in part time 4WD (because you only run in 2WD for regular driving).

In addition, full time 4WD will get you worse mileage because you have more unnecessarily rotating mass than running in 2WD. Besides the transmission, rear axle and driveshaft, you also have the front driveshaft, both front half-shafts and front differential chunk are all rotating. With part-time 4WD, you can shift into 2Hi and disengage the front hubs, and the only things rotating on your front end are the tires and hubs, the half-shafts, front chunk, front driveshaft and u-joints just freewheel.

If the U-joints have been replaced recently you probably don't have much to worry about, and you could probably get a little bit of mileage and better tire wear by switching the front hubs to part-time hubs until you get either a part-time kit or different transfer case for the truck.

[78K5]

the truck has already been converted to "part-time" or whatever, and im sure it was done a pretty reasonably long time ago