1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

14 Bolt Full Float / Semi Float Identification

Discussion in 'Differential & Driveline' started by HotRodPC, Jan 30, 2011.

  1. HotRodPC

    HotRodPC Administrator Staff Member

    Posts:
    44,500
    Likes Received:
    4,271
    Joined:
    Aug 29, 2010
    Location:
    OKC, OK
    First Name:
    HotRod
    Truck Year:
    85
    Truck Model:
    Silverado K10 to K20 Conversion
    Engine Size:
    6.2 to Gas???
    For those who are not aware. Very easy to tell the difference in a 14 Bolt Full Float and a 14 Bolt Semi Float.

    Full Float has the axle hub sticking out of the drum or wheel.
    Full Float is a 10.5 inch Ring Gear and doesn't require C clips.


    Semi Float DOES NOT have the hub sticking out of the drum or wheel.
    Semi Float is a 9.5 inch Ring Gear and uses C clips in the carrier to retain the axles.

    Here is a photo of the rear covers to help you ID the different 14 bolts. Very easy to tell the difference.

    [​IMG]

    This is what G80 Locking Diff Gov Lok Carrier looks like in a 14b FF.
    [​IMG]
     

    Attached Files:

    Last edited: Feb 2, 2011
  2. 1low4x4

    1low4x4 Full Access Member

    Age:
    34
    Posts:
    2,298
    Likes Received:
    71
    Joined:
    Feb 14, 2011
    Location:
    Texas
    First Name:
    Nick
    Truck Year:
    1984
    Truck Model:
    K10
    Engine Size:
    5.7
    Thanks for the tip. Can you elaborate more on what is special about both, I.e. What makes one better than the other, and what are each designed to do?
     
  3. crazy4offroad

    crazy4offroad Service Bullshit Filter Soon

    Age:
    47
    Posts:
    8,411
    Likes Received:
    757
    Joined:
    Jul 30, 2010
    Location:
    West BY-GOD Virginia
    First Name:
    Curt
    Truck Year:
    1977
    Truck Model:
    One-Ton K-10
    Engine Size:
    350/TH350/NP205
    14b SF is the in-between for the 10-bolt and the D60. They dont have full-floating axleshafts like the 14b FF does. Meaning the wheel hubs ride on bearings attached to the axleshafts, where the FF has axleshafts that pass through the hub and have no vertical load on them at all, just rotational load. Also I believe the SF has a 9.5" ring gear and the FF has a 10.5" ring gear.
     
  4. HotRodPC

    HotRodPC Administrator Staff Member

    Posts:
    44,500
    Likes Received:
    4,271
    Joined:
    Aug 29, 2010
    Location:
    OKC, OK
    First Name:
    HotRod
    Truck Year:
    85
    Truck Model:
    Silverado K10 to K20 Conversion
    Engine Size:
    6.2 to Gas???
    Yes, you are right. 9.5inch ring gear in the 14B SF. The SF also uses C clips to keep the axles in. It comes in both 8 lug and 6 lug varieties. So it makes a great upgrade if you have a K10 and want to go to a stronger rear axle. You just have to find the 6 lug axles for it then you can keep you front axles to same also. The most common ratio in the SF for a Square body version is 4.10 and next to never came with a G80 Locking Diff from the factory. I think it was about around 81 when GM went to the SF for standard OEM equipment in the 3/4 tons. If you got the 14B Full Float in a 3/4 after that, you normally had the Heavier Duty RPO code.

    The 14b FF is the most preferred for strength, has floating axles that do not need C clips since the outer hub bolts are what hold the axles in. Pure brute strength in axles and 10.5 in ring gear and why all the rock crawlers want 14b FF. I'd say its strgegth falls between Dana 60 and Dana 70. Just a good rock soldi axle for light trucks up to 1 ton. This is also what the military used in its CUCV's.
     
  5. bucket

    bucket Super Moderator Staff Member

    Age:
    38
    Posts:
    19,762
    Likes Received:
    4,645
    Joined:
    Aug 3, 2010
    Location:
    Usually not in Ohio
    First Name:
    Andy
    Truck Year:
    '77, '78, '79, '84, '88
    Truck Model:
    K5 thru K30
    Engine Size:
    350-454
    I'd like to point out that the 6 lug version was only used in the newer body style trucks. Spring perch relocation is required for installation in a square body. It also was available as a 5 lug, but only in the 454 SS.
     
  6. RetroC10Sport

    RetroC10Sport Super Moderator Staff Member

    Posts:
    16,704
    Likes Received:
    809
    Joined:
    Sep 29, 2010
    Location:
    Austin, Tx/FEMA Region 6
    First Name:
    Jay
    Truck Year:
    1989; 2001
    Truck Model:
    GMC Sierra C1500 SportSide, Aztek GT
    Engine Size:
    5.7, 3.4;
    Wish I had a pic of the rear end in a 1970s Cadillac hearse...You want to talk HEAVY DUTY with a 5x5 pattern...I think it would be possible to put one in a SB, but not sure if any posi or lockers are available for it as I don't know who made it.
     
  7. HotRodPC

    HotRodPC Administrator Staff Member

    Posts:
    44,500
    Likes Received:
    4,271
    Joined:
    Aug 29, 2010
    Location:
    OKC, OK
    First Name:
    HotRod
    Truck Year:
    85
    Truck Model:
    Silverado K10 to K20 Conversion
    Engine Size:
    6.2 to Gas???
    I have heard this before too. I have also heard both ways also, that the axles from the NBS will fit the SB rear end, and I have also heard they will not. :shrug:
     
  8. bucket

    bucket Super Moderator Staff Member

    Age:
    38
    Posts:
    19,762
    Likes Received:
    4,645
    Joined:
    Aug 3, 2010
    Location:
    Usually not in Ohio
    First Name:
    Andy
    Truck Year:
    '77, '78, '79, '84, '88
    Truck Model:
    K5 thru K30
    Engine Size:
    350-454
    A member on CK5 did the shaft swap, it's not a direct replacement. IIRC, it involved mixing and matching drums and brake parts, as well as spacing out the backing plates.
     
  9. HotRodPC

    HotRodPC Administrator Staff Member

    Posts:
    44,500
    Likes Received:
    4,271
    Joined:
    Aug 29, 2010
    Location:
    OKC, OK
    First Name:
    HotRod
    Truck Year:
    85
    Truck Model:
    Silverado K10 to K20 Conversion
    Engine Size:
    6.2 to Gas???
    Sounds like it might be easier just to relocate the spring perches.
     
  10. saveitforsunrise

    saveitforsunrise Junior Member

    Age:
    27
    Posts:
    1
    Likes Received:
    0
    Joined:
    Apr 19, 2012
    Location:
    Thomasville, Ga
    First Name:
    Joe
    Truck Year:
    85
    Truck Model:
    k10
    Engine Size:
    mexican 350 4 bolt
    New here, first post, the 14 bolt sf will not fit in a sb without relocation of spring perches and shock mounts, the 14bsf out of a obs truck is also slightly wider by around 3 inches iirc, so if you have a 4x4 the axle width matches better for the 10 bolt fronts, if you go out and look at your stock 4x4 the rear is narrower than the front, this really helped the looks department with me, is you look down the side of my truck now both tires acctually line up!!!
     
  11. HotRodPC

    HotRodPC Administrator Staff Member

    Posts:
    44,500
    Likes Received:
    4,271
    Joined:
    Aug 29, 2010
    Location:
    OKC, OK
    First Name:
    HotRod
    Truck Year:
    85
    Truck Model:
    Silverado K10 to K20 Conversion
    Engine Size:
    6.2 to Gas???
    This all depends which SF you have. Squares came from the factory with 14b SF since 1981 so they do fit and bolt right in, if it's a squarebody OEM SF axle.

    I've been told the 88-98 2wd rear axles are 3 inches to narrow, but the 4wd 88-98's are the same width 68 inches wms to wms (wheel mounting surface) but yes, they'd have to have the spring perches relocated to put a 88-98 SF axle in a Squarebody truck, burb or blazer/jimmy.
     
  12. Grater

    Grater Junior Member

    Age:
    31
    Posts:
    1
    Likes Received:
    0
    Joined:
    Jan 4, 2013
    Location:
    Russia
    First Name:
    Mike
    Truck Year:
    1994
    Truck Model:
    Suburban k2500
    Engine Size:
    5.7 TBI
    Hey guys! Just wandering can I fit drum brake hardware kit from k30 with full floater axle to my Suburban with semi floater? they have same 13" drums
     
  13. HotRodPC

    HotRodPC Administrator Staff Member

    Posts:
    44,500
    Likes Received:
    4,271
    Joined:
    Aug 29, 2010
    Location:
    OKC, OK
    First Name:
    HotRod
    Truck Year:
    85
    Truck Model:
    Silverado K10 to K20 Conversion
    Engine Size:
    6.2 to Gas???
    No. Because of the hub that sticks out of the FF. You're axles wouldn't be long enough either.
     
  14. TRokk

    TRokk Junior Member

    Age:
    28
    Posts:
    27
    Likes Received:
    0
    Joined:
    May 30, 2013
    Location:
    Randle
    First Name:
    Jeff
    Truck Year:
    1973
    Truck Model:
    Sierra 1500
    Engine Size:
    350 5.7 V8
    I have a 14b back axle that has a ratio of 3.73, but also guys its an 8 lug, 3/4 ton axle.
    so this would be a FF right?

    14boltBackAxle_zps499ed2b6.jpg

    And the number's on the right side, I don't understand what they are supposed to mean?
     
    Last edited: Jun 1, 2013
  15. crazy4offroad

    crazy4offroad Service Bullshit Filter Soon

    Age:
    47
    Posts:
    8,411
    Likes Received:
    757
    Joined:
    Jul 30, 2010
    Location:
    West BY-GOD Virginia
    First Name:
    Curt
    Truck Year:
    1977
    Truck Model:
    One-Ton K-10
    Engine Size:
    350/TH350/NP205
    The 10 bolt front is used for both 1/2 and 3/4 ton trucks, with only the hubs different for the lug patterns. 1-ton has the Dana 60.
     

Share This Page