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14bFF disc conversion - wheel stud fitment - is this normal?

Discussion in 'The Garage' started by Shaggy, Dec 24, 2002.

  1. Shaggy

    Shaggy 3/4 ton status

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    <font color="green"> OK, the axle is from an 87 SRW 1 ton. I asked for rotors for a '78 3/4 ton. The recesses on the back of the rotor were not large enough for the heads to drop all the way into, so I had to turn about .2" off of all of the studs. Is this normal, is it just because the axle was from a 1 ton, or was I supposed to buy new studs? It works fine so I'm not going to replace them, I'm just curious about it since I hadn't heard anything about this issue in any of the hundreds of disc conversion threads. Pics -

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  2. bablazer73

    bablazer73 1/2 ton status

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    When I did my 3/4 ton 14ff, the studs were to short. had to use front studs.they are longer. the heads were ok though.
     
  3. Triaged

    Triaged 1/2 ton status

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    I bought some rotors from autozone for a 78 3/4 ton as well. They had holes in the back of them that were big enough...but the rotors that were on the front end (which I ended up using in the rear so I could have the new rotors in the front) didn't have a big enough hole. I just bolted it together and called it good. I like you solution better.
     
  4. Sandman

    Sandman 3/4 ton status Author

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    The rotors that I bought had the holes big enough. I wonder if its just an aftermarket brand thing.
     
  5. beater74

    beater74 1/2 ton status

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    no issues with mine
     
  6. fortcollinsram

    fortcollinsram 1/2 ton status

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    I had the same problems...the 3/4 rotors I bought from Napa had a recess that was 1" in dia. and the wheel studs had a head dia of 1.12" /forums/images/graemlins/eek.gif So I turned down the head .12"...also the studs I bought were too long so I trimmed .25" of the OAL....perfect fit now... /forums/images/graemlins/thumb.gif
     
  7. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    I had no issues with mine. I used my old front rotors from a 77 D44. The wheel studs from my one ton 14 bolt fit fine and weren't too long either.

    The only minor snag i ran into was a small cast tab on the caliper needed to be ground off to let it bolt up to the bracket. 2 minutes with the grinder...

    Rene
     
  8. HarryH3

    HarryH3 1 ton status Author

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    I did mine several years ago, using the TSM brackets that required rotors from the front of an F-250. The recesses in the back of the Ford rotors are too small for the GM studs, so TSM offered rotors with the holes machines out larger, but they were expensive! So I bought the rotors locally from Autozone for $34 each and used a bench grinder to remove a small amount of material from the heads of the studs, just like you're describing. /forums/images/graemlins/cool.gif This way I can use an off-the-shelf rotor if I ever manage to damage one. Those studs are massive, so I seriously doubt that this would cause much of a problem with strength. /forums/images/graemlins/thumb.gif
     
  9. TONYP

    TONYP 1/2 ton status

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    I did the same, but mine was cause I have that 8 lug to 6 lug ring I made to keep my 6 lug rims. You can tell people even the wheel studs are custom...
     
  10. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Shaggy,

    That happens sometimes.... Scott (4x4HIGH) told me the same exact story as you when he did his rear disc brake conversion...all the bolts had to be turned down or they wouldn't seat right (dangerous!)

    I pulled my entire rear wheel assemblies apart (for about the 3rd time) expecting that we were going to have to do the machining on my bolts as well. For some strange reason, mine were fine and didn't need machining....my only guess is there are slight variations in the suppliers of rear disc rotors (which are actually 3/4-Ton fronts right?) and sometimes there is an extra edge there that interferes....

    Weird, but true. Just another one of those THINGS that people don't realize about the "so called" simple 14BFF swaps....! /forums/images/graemlins/eek.gif
     
  11. bigbluek20

    bigbluek20 1/2 ton status

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    What year did GM switch to the 14FF that had drums independent of the hub/bearing assembly?

    My axle is from a 78 (I think) and it went together fine with the D44/10Bolt Rotors
     
  12. Shaggy

    Shaggy 3/4 ton status

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    <font color="green"> Thanks for the replies, guys. Sounds like this is just one of those "sometimes" things that sometimes needs to be dealt with during the disc swap. Hopefully this thread will help someone else be prepared later on. /forums/images/graemlins/thumb.gif </font color>
     
  13. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    I happened to read this yesterday. I go to press the studs in the hubs and check the heads first . /forums/images/graemlins/shocked.gif /forums/images/graemlins/mad.gif

    I did the same ordered 78 3/4 ton front rotors this is going on my "3/4 ton" 14 bolt.
    Rotors Part #105014
    New wheel Studs 9/16-18 x 3" Part # 610-189

    I used a t snap gauge and calipers.
    Rotor hole- 1.033"
    Wheel stud head- 1.121"

    The Wheel studs we are grinding have a 1 1/8" head I turned all 16 on a lathe down to 1.000" head diam and pressed em in.
    /forums/images/graemlins/thumb.gif

    I wonder if the problem is the other guys have wheel studs with 1" heads or is it the manufacturers variations of rotors with a countersink hole larger than 1"? /forums/images/graemlins/ignore.gif /forums/images/graemlins/rolleyes.gif
     
  14. TONYP

    TONYP 1/2 ton status

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    I turned mine down to 1.00" to fit my spacer ring..

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