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14 bolt spring pad width

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by JST12, Sep 25, 2000.

  1. JST12

    JST12 1/2 ton status

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    Well, I've got the '71 completely disassembled down to the frame. Ready for sandblasting. When I put it back together it will have a Corp 14 bolt. Thus I need a 14 bolt from somewhere. Does anyone know if it matters what type of vehicle and what year the donor comes from? I am thinking of the spring pad width to match the first gen K5 leaf springs. Was the axle width changed in '73 like the rest of the vehicle? If I must re-weld the pads, so be it. I would like to find a cheap un-rebuilt SF or FF unit if anyone has one around Dallas. Thanks, JT
     
  2. Emmettology 101

    Emmettology 101 3/4 ton status

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    For either, you will have to get a rear end from a single wheel p/u or Suburban... The dualies have a different spring width...

    HTH

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  3. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    On mine the width of the spring pads is 2 1/2". The dimension of the pads center to center is 42 3/4" as near as I can measure. My 14 bolt FF is from a '76 K20 pick-up.

    Hope that helps.

    Rene

    [​IMG]
     
  4. JST12

    JST12 1/2 ton status

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    Rene, Thanks for the measurement! I'll measure my old 12 bolt and that should tell me whether or not anything is different between the generations. JT
     
  5. Chris Demartini

    Chris Demartini 1/2 ton status

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    <font color=blue>You need to get one from a 73-87 1 ton p/u, they have the perches in the right spots. I have one in my driveway and I measured the centering pin distance and it the same as the 12 in my truck now.</font color=blue>

    http://www.chrisd71k5.coloradok5.com <font color=blue></font color=blue>
     
  6. blazer72

    blazer72 1/2 ton status

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    When I last changed out the 12 bolt in my 72 I found that the 12 bolt from a 77 was to wide. Had to cut the old pads off and move the new ones in about 1 3/8 or so on each side so it looks like the change was in 73 the pads are the same just in difrent places on the axel!

    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  7. nyyef

    nyyef 1/2 ton status

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    so it just bolted right in? what about the driveshaft and the ujoints, any modifications needed there?
    TIA

    Knife.
    knife.coloradok5.com
     
  8. JST12

    JST12 1/2 ton status

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    Thanks for the info. I measured the center to center on the spring pads of the'71 12-Bolt and they are 40 inches apart. Looks like the 73+ frame is indeed almost 3 inches wider. Next stupid question: Did GM offer 14-bolt axles on the 69-72 20 series pickups which might have the correct spacing, or were these old pickups all coil-spring rears?
     
  9. blazer72

    blazer72 1/2 ton status

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    All 4 wheel drive and GMC had leaf springs, only the chevy 2 wheel drive 1/2 ton had coil springs and even that is not in stone. I have seen the GMC 2 wheel with coil and a 3/4 ton chevy with coil. The good part is that all of the 8 bolt 3/4 where the full floater [​IMG]

    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  10. Chris Demartini

    Chris Demartini 1/2 ton status

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    <font color=blue>Chevy didnt make the 14 bolt ff until 73. You measured a 3/4 ton frame, you need one from a 1 ton truck. The spring pad distance is the same on the 73-87 1 tons as it is on the 1st gen K5s.</font color=blue>

    http://www.chrisd71k5.coloradok5.com <font color=blue></font color=blue>
     
  11. JST12

    JST12 1/2 ton status

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    Thanks biggray. I'm on my way to the wrecking yard. They say they have several 1 ton axles to choose from. I know I'm wearing out my welcome here ... but how can one tell whether the axle is FF or SF? I know the FF has all the weight on the bearings and spindle as opposed to the axle shafts, but how is it identified vs the semi-floating?
     
  12. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    First off the F.F. axle will have a hub coming out fron the center of the drum. At the end of this hub there should be 6 bolts, these bolts are actually holding the axle in the housing.
    A Full Floater places none of the vehicle weight on the axles, in fact you can remove the axles without jacking up the truck or even taking the tires off.
    If you find a semi-floater it will look like a 10 or 12 bolt at the drum. A semi-floater will allow you to remove the drum with a simple tug, the FF is on a spindle just like the front.
    Clear as mud?

    Rene

    [​IMG]
     
  13. TX Mudder

    TX Mudder 1/2 ton status

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    There are 8 bolts holding the axleshaft on.
    Not a big deal, but if he goes to the jyard looking for one, he won't find any with 6 bolts.
    -- Mike
     
  14. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Corrected again [​IMG] I was'nt sure and was too lazy to pull off the hub cap and double check. Thanks

    Rene[​IMG]

    [​IMG]
     
  15. JST12

    JST12 1/2 ton status

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    Thanks tRusty and TXMudder. The info helps a ton.
    JT
     

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