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Factory rear diff

Discussion in 'The Garage' started by MoabMike, Mar 8, 2005.

  1. MoabMike

    MoabMike Newbie

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    I have a 87 Blazer with 3.73 gears. Is the rear differential open, or limited slip? How can i tell?
     
  2. muddyblzr

    muddyblzr 1/2 ton status

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    put the rearend up on jacks and put it in nuetral. spin one of the tires with your hand if the other tire spins the same direction its either a govlock or limited slip, if it spins the opposite direction its an open diff.
     
  3. k20

    k20 3/4 ton status

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    look on your rpo code list for g80 (Im pretty sure one of those is the gov-loc rearend). Look at your rpo code list, in the glovebox, and it may have descriptions of each code. If not, look at the 'g' section, and then reference the codes here http://www.angelfire.com/ny2/96transam/rpocodes.html

    The most fullproof way is to just pop the cover and have a look. If all you see is ring gear, and normal lookin stuff (dont know how to describe lol) its open. If it looks really frickin weird, its a posi.

    If the posi is worn, jacking it up wont necesarily tell you if you have one, you may have one, but it may not be functioning.
     
  4. muddyblzr

    muddyblzr 1/2 ton status

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    that true poppin the cover is the best way but jackin it up is quick and easy. the posi in the 12 bolt i have lieing around is kinda worn i think cuz whne i turn one tire the other one kinda lags behind maybe that normal im not sure
     
  5. Blazer1970

    Blazer1970 1/2 ton status

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    With a Gov-lock the opposite tire will spin backward just like an open diff. Look for RPO G80 in the glove box or pull the cover.
     
  6. R72K5

    R72K5 Banned

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    will never know for sure til you open it,


    gov loks dont do crap til theres 100 rpm difference between axle shafts,

    then most the time they liek to grenade, heh

    good luck
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    If you can get the rear up in the air, as long as the tires spin freely, if its a gov-lock and *if* it's working correctly, you can spin one tire as fast as possible (just right off the bat, don't need to sit there and spin it for minutes) and you'll feel it lock up.
     

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