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4 wheel high

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 1979Jimmy, Nov 28, 2001.

  1. 1979Jimmy

    1979Jimmy 1/2 ton status

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    If im driving and my axles are locked can I shift between 4hi and neutral at speed?

    79 Jimmy, 5" lift 35 M/T with a 383 puttin out 400hp and 450lb/ft. Locked front and back.
     
  2. jimmyjack

    jimmyjack 1/2 ton status

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    No, when you shift between 2 and 4 hi you are only engaging the front frive shaft. When you shift to neutral or lo you are putting a planetary gear into action. The truck basically needs to be standing still to correctly mesh the gears.

    That jeep thing? Yah I understand it....... Like my Blazer? <a target="_blank" href=http://community.webshots.com/user/blazerk5>http://community.webshots.com/user/blazerk5</a>
    Jim
     
  3. michaelm

    michaelm 1/2 ton status

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    yes you can,
    which transfer case do you have
     
  4. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    NP203's are shift On the fly. Yes you can shift between gears while moving. If your going to loc your ok up to about 35mph. If your going from High to Low. 15mph MAX the slower the better going into low. Comming out of low to high is fine.
    Going to LOC just let it coast and go for it.
    Going to LOW from High or Low to high put the tranny in Neutral and coast. You do not want to be in Drive when you go through Neutral on the case. It Will grind.
    I'm locked front and rear and so I can lighten up the steering I come in and out of Loc a lot while moving.

    Women dig dents and flat paint!
    coloradok5.com/gallery/Grim
    75 Jimmy, Dollar
    Grim-Reaper
     
  5. 1979Jimmy

    1979Jimmy 1/2 ton status

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    What would be the best way to determine what my transfer case is im not exactly sure i think it is a np203 though.

    79 Jimmy, 5" lift 35 M/T with a 383 puttin out 400hp and 450lb/ft. Locked front and back.
     
  6. BowtieBlazer

    BowtieBlazer 1/2 ton status

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    What about any such thing as shift on the fly with a 208 and sm465? I remember reading somethign about them being diff from haveing an auto slushbox backed by a 208

    What? You think the hole is too deep? Lemme see...
    1985 GMC C-10 Shortbed
    1984 Chevy K-5 Blazer
     
  7. muddysub

    muddysub 1 ton suburban status Staff Member Moderator GMOTM Winner

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    i've heard the 241 can shift on the fly. is that true?

    people that get good mileage aren't having any fun!
    scott,
    1989 GMC suburban 3/4t 4" lift finally rollin on 36" swampers, tbi350, th350, np241
     
  8. Thunder

    Thunder 3/4 ton status

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    Yes its true.
    I shift my 241 in and out between 2 hi and 4 high on the fly all the time. Just did it this mornin when I left the snowy roads in town and got on the interstate.It shifts very smooth at any speed below 55 mph with absoultly no grinding. All I have to do is let of the gas and shift.
    Of course like any transfer case, you have to come to a stop to shift it into 4 low.

    <a target="_blank" href=http://coloradok5.com/gallery/Thunders-Blaze>http://coloradok5.com/gallery/Thunders-Blaze</a>
    <font color=blue>NEVADA: Where the pavement ends, and the West begins.</font color=blue>
     
  9. michaelm

    michaelm 1/2 ton status

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    I think any locking hubs equiped transfer case can go from 2 hi to 4 hi and vice versa.
    as the gears would be turning equal speeds.
    a 205 you can shift through any gear on the fly with the hubs locked. it is just a non syncro 1.96:1 gear box
     
  10. Blazer79

    Blazer79 1/2 ton status

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    Location:
    Guatemala, Central America
    The NP203 shifter says HI-LOC, HI, N, LO, LO-LOC from front to rear.

    ...and yes, I always shift my NP203 on the fly. Just do it slowly but firmly. I also always shift the tranny to neutral just to prevent any grinding.

    <font color=purple>//////
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    Soon a 454 K5!!</font color=black>
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  11. bking

    bking 1/2 ton status

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    Well, here in AK at the min the roads are drying out a lot, nice and dry on the straights, dead meat at intersections, I leave mine in 4 hi til April...no side effects as yet...
     
  12. bking

    bking 1/2 ton status

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    Well, here in AK at the min the roads are drying out a lot, nice and dry on the straights, dead meat at intersections, I leave mine in 4 hi til April...no side effects as yet...
     
  13. jimmyjack

    jimmyjack 1/2 ton status

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    A 208 or 205 can shift between 2 and 4 hi on the fly with no problem. Like I said before when you shift into lo gear you engage a planetary gear so you basically hafta be at a stand still. (at least in my experiences)

    That jeep thing? Yah I understand it....... Like my Blazer? <a target="_blank" href=http://community.webshots.com/user/blazerk5>http://community.webshots.com/user/blazerk5</a>
    Jim
     

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