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Full time 4WD

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Hooty, May 17, 2001.

  1. Hooty

    Hooty Registered Member

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    My 78 K5 has full time 4WD I am wondering how hard it is to change it over and is it worth it? It has high, low,high lock, and low lock...I am sorta new to 4WD have been plenty of times but never owned one so any help is greatly appreciated.
     
  2. Wheels

    Wheels 1/2 ton status

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    There are two different ways to convert over to part time on a New Process 203 transfer case (which sounds like what you have). One is a kit that replaces the spider gears in the output shaft (about $100) and the other is a complete shaft conversion (about $300). The shaft conversion is the best of them but you will still have to shift into hi-loc ocassionally to get oil up to the rear output bearing. Mile Marker makes these kits complete with the hubs, or you buy the parts individually. Summit Racing has them in their catalogs.
     
  3. slider79blazer

    slider79blazer 1/2 ton status

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    I put the spider gear kit in mine $50 i never did it before but it was very simple i took my time and it took about 3 hours to do.

    whats a 4 letter word for farm wagon? (ford) [​IMG]
     
  4. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Keep the tires rotated and leave it the hell alone. Part time converting them is the worst thing you can do to them. The rear bearings get fried. They were designed to have the oil circulated by the chain. If you must covert it go with the better kit. Remember to shift into LOC every couple of hundred miles to keep it lubricated. I personaly feel the cheap kit makes the case much weaker than stock. That kit binds side ways under heavy load and puts a lot of pressure on the rear bearing that it wasn't designed for. The other kit is as strong and being a solid peice it doesn't beat on the bearing but still has the lubrication issue. I have 2 trucks with this case and one was converted when I got it. It had a super winch part time kit tear up and I replaced it with the cheap Mile Marker kit before I knew the other kit was available. That case is in so much worse shape than my 75 that is still full time. It makes noise all the time and vibrates. The truck that is still full time has been abused for years by the previous owner and neglectd with maintance and that case feels so much better.
    Don't let anybody tell you those are junk. I'm about to have to replace my chain...gee $90 part after 300k of full time use. Yeah right it's junk. It got it bad rep from people converting them to part time and buring them up. I can garantee that there is not a full time case on the market that can run 300k without a problem. Heck most of the part time cases fry on the street without much wheeling. The only case stronger than what you have that came in the truck is a NP205. Those are darn hard to find for a TH350.

    Diging it in the dirt with my K5's
    Grim-Reaper
    <A target="_blank" HREF=http://grimsk5s.coloradok5.com/>http://grimsk5s.coloradok5.com/</A>
     
  5. Hooty

    Hooty Registered Member

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    Thanks I think thats what I'll do just leave it alone it seems solid ... And thats a hell of an argument 300k and only $90 those are my kinda maintenance costs.
     
  6. azblazor

    azblazor 1/2 ton status Premium Member

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    I agree with Grim. Same pattern on my trucks. Full time -good longevity. I'm preparing to rebuild a full time 203 with almost 300K. Never a problem, its leaking now with some slop - but still running and shifting strong.
    azblazor
     
  7. mrivan

    mrivan 1/2 ton status

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    I bought a 1/2 ton( 350 350) with full time new in 1975 ,it was a stripped model no radio rubber floor mats ect. but it cost $5150 out the door and turned out to be a good running tough truck .I lived in the U.P. mich.at the time and ran it hard in soft beach sand and heavy snow and really like the full time even though it only got about 12 mph ,but that was over all with a lot of hard running in low loc....the only problem I found was that it was so good on the hard packed snow roads that we had from early Nov. to late April that it gave you a false sence how slippery the roads really were till you had to use your brakes.........
    Mrivan......
     
  8. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Hey Grim, didn't someone come out with a "slinger" to fix that oiling problem? Seems like I saw that one of the more expensive kits was including a slinger, not sure though.

    Anyway, I think the only reason I would consider converting it is to save wear on the front drive components. Especially with a significantly lifted truck and pretty severe front drive line angles, making the shaft turn all the time will tend to eat up u-joints. Saving wear on the knuckle joints might be worth noting too. But, I ran my 76 Scottsdale SWB for years with a full time and 4" lift with no problems so I probably wouldn’t touch it if I had one again, except maybe to convert to a 205. And I would do that only because it is smaller, lighter, simpler, AND part time. It’s really not that much stronger than a 203. They are both rated in excess of 10,000 pounds.

    Bad Dog

    85 K30 CUCV, 350 TBI, TH400, NP205, D60/C14, 4.56 Locked
    Soon: 4" lift, 40" tires, massive cutting, shorter wb and rear overhang.
     
  9. Blazer79

    Blazer79 1/2 ton status

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    Haven't you noticed that full-time 4wd is one of the fashion features found in many of today's SUVs? So when the next cool new SUV owner comes out showing off about the new features of his new "off-road vehicle", you can answer in a cool, relaxed voice: "mine has that too since 1978."

    I, of course, say keep it. Mileage won't improve by converting it either. Mileage is bad becase Blazers are heavy and anti-areodynamic.

    <font color=blue>//////
    <A target="_blank" HREF=http://blazer79.coloradok5.com>http://blazer79.coloradok5.com</A>
    </font color=blue>[​IMG]
     
  10. Cr1028

    Cr1028 Registered Member

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    If it is full time 4wd, what does shifting into loc do?

    81 K5
     
  11. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Full time 4WD has a differential inside it just like an open axle differential and for the same reason. When driving on the street, the front and rear can actually turn at slightly different speeds to keep the drive train from binding and bucking. This differential has the same problem off-road that and open axle diff does, it will allow a single wheel spinning in the air to stop you completely. So, putting it in lock effectively locks the t-case diff just like an ARB would selectively lock up an axle diff. This will at least force BOTH the front and diffs to turn, how many tires turn then depends on what is in the axle diffs...

    Bad Dog

    85 K30 CUCV, 350 TBI, TH400, NP205, D60/C14, 4.56 Locked
    Soon: 4" lift, 40" tires, massive cutting, shorter wb and rear overhang.
     
  12. Hooty

    Hooty Registered Member

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    I decided to keep it full time no question especially to tell those SUV owners I've had it since 78 thanks for the help guys great forum I've got some really good information from here.
     

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