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12b build up.

Discussion in 'The Garage' started by cwn anwyn, Mar 18, 2007.

  1. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

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    Here are some pics of my little 12b build. I did the disc brake conversion from the tech articles, replaced seals, and put in a longer center hose for the brakes. I also dropped in a mini spool at the same time. I used the backing plates and calipers from my old stock 10b front that I had laying around. (I did end up buying new calipers since one of my old ones was shot. But they are pretty cheap). This doesnt have any provisions for an ebrake.

    The part numbers and prices were:
    Mini spool- Richmond #836-78-1230-1836-78-1230-1 from Jegs 89.99
    Rotors for an 89 K1500 P/U (2)- #5977RG Checkers 22.99ea
    Brake lines for calipers (2)- #4136847 Napa 10.99 ea
    Longer center brake hose- #4138068 Napa 16.99
    Axle seals (2)- 16044 Checkers =2.39 ea
    Conversion Ujoint for 12b to old 10b shaft(S44 to 1310)- Neapco 3-3130, Checkers part number is 215-0356 10.99
    Brake calipers for an 84 K5 front- 184208/184209 12.99 (w/20.00 core)

    1st I took off the old brake drum parts and axle shafts.
    [​IMG]
    You have to remove the center pin and bolt, plus the spider gears to get to the side gears and c-clips.
    [​IMG]
    Side gear and c-clip.
    [​IMG]

    Axle shaft is gone.:D
    [​IMG]
    Drums are gone, now onto the old seal.
    [​IMG]
    I swapped in the new seals
    [​IMG]

    Then I moved onto the backing plates.
    I had to remove the lip/cup around the center opening since it wouldnt let the axle shaft go in enough to put the c clip back.

    [​IMG]

    So I ground it off.
    [​IMG]

    Next I drilled a couple of new holes and elongated a couple of the old ones (I know their not pretty, but it was trial and error at first:D ). You can see my orientation markings on where I wanted the caliper to sit (12 oclock/6 oclock).
    [​IMG]

    Once the backing plates were done, and my calipers ready. It was time to start assembling them. After many test fittings I finally was able to get everything to go together the way I wanted them.

    I bolted the backing plates on with new hardware. Then I installed the axle shafts. Next came the new rotors. I had the center section machined out by a local shop. The hub diameter on the 12b was 3.578, the local shop machined the centers out to 3.581 (their next available size). The machine work cost me 30 dollars, and was done overnight.
    [​IMG]

    Then I installed the calipers and fresh pads, along with the brake lines. I was able to rebend the old steel lines on the axle so I could run the hoses out of the way.
    [​IMG]

    [​IMG]

    In the pic above, you can see that I had to grind quite a bit from the lower edge of the brake pad (and a little bit off the lower projections of the calipers). I kept getting some contact between the pad and rotor hat.
    I have had no issues after removing all of that material, and the brakes have been on my DD for 3-4 months now.

    As I was doing the swap, I was also dropping in the mini spool. It was a pretty easy, straight forward install.

    [​IMG]

    After removing the spiders and sidegears, I installed half of the spool inplace of one of the side gears.

    [​IMG]

    I then re-installed the c-clip, and repeated the process for the other side.
    [​IMG]

    I then installed the spools center blocks. I did have to bevel the inner edges a bit to get them to install correctly.

    [​IMG]

    I then rotated it and re-installed the centerpin and bolt.
    [​IMG]


    Overall, I think both of these mods came out pretty good. Braking was improved and the spool has helped out tremendously. I also really like it in the snow and ice packed roads. I've slid a few times driving to work before doing this, and with the spool installed it was 100 times more predictable and easier to recover from any sliding.:D

    Z
     
    Last edited by a moderator: Mar 19, 2007
  2. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    Beautiful . Could you trace and scan the backing plate pattern , with dimensions ? That would be an awesome thing to do , and would help out many of us :thumb:
     
  3. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

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    I'll have to see if I still have my sketch still out in the garage. If not, I can easily retrace it and post it up later.

    Z
     
  4. Bigdawg234

    Bigdawg234 Registered Member

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    that would be awesome if you posted a diagram.
     
  5. Hitches31

    Hitches31 Registered Member

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    Conversion Ujoint for 12b to old 10b shaft(S44 to 1310)- Neapco 3-3130, Checkers part number is 215-0356 10.99

    Nice job . I haven't swaped my 12 bolt into my truck yet to replace my corp 10. When you listed the part number and said 12b to old 10b shaft (( Are you talking the drive shaft u-joint at the rear end?
     
  6. GotLabs

    GotLabs 1/2 ton status GMOTM Winner

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    Great write up.
     
  7. big dan

    big dan 1/2 ton status Premium Member

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    awesome work. glad to see Im not the only one thats still gonna be using a half ton rear.:o

    I was fixing to get started doing the exact same mods and then my motor spun a bearing so it looks like Im gonna have to hold off.
     
  8. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

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    Thanks guys,

    I'll have to rework the diagram, since I couldnt find the old one. But I'll get that scanned up soon.

    Yep, thats the conversion joint you need.:D I thought I may have worded that wierd.:doah:

    Z
     
  9. Hitches31

    Hitches31 Registered Member

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    Nope just checking on the u-joint, Because I should be doing my swap very soon
     
  10. 70GMC

    70GMC Registered Member

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    this is awesome. it seems like all of the companys out there that made 6 lug disc brake kits for the 12b went out of business. all i've been able to find is 5 lug kits
     
  11. RedBrute

    RedBrute 1/2 ton status

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    What did you do to make up for the larger stud hole in the rotor vs the stock 7/16 stud?
     
  12. mrk5

    mrk5 The Sticker Guy Moderator Vendor GMOTM Winner Author

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    Nice work Zach! :waytogo:

    Surely you'll be hitting some trails with us this year! :saweet:

    Get that axle in the truck so you can tell me how you like the spool!
     
  13. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

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    I didnt use anything to make up for the difference in stud size. The write up mentioned using cuts of pvc to shim around the studs. I tried that and then decided to not bother with it. I did use open end lug nuts to hold the rotors inplace during all fittings and trials. Then I mounted the rotors and wheels without any shims. After running this setup for the past few months, I have had no issues with the rotors moving around on me.

    Z
     
  14. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

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    Thanks!:D

    I've had this on in for awhile now. I love the spool! I can tell I will be going through rear tires a little quicker.:doah: Its actually kind of funny when I make a slow turn, I get a lot of looks.:eek1: :haha:

    Z
     
  15. NoReGrEtS

    NoReGrEtS 1/2 ton status

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    what size tires are you running?
    and nice right up:waytogo:
     
  16. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

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    Right now I am running 36" TSL radials, 4.56 gears.

    Z
     
  17. 55Willy

    55Willy 3/4 ton status

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    I just did the same spool in my 12 bolt and I can't get the spool to turn to allow for the pin to go back in. did you have any issues getting yours to spin to line back up?
     
  18. cwn anwyn

    cwn anwyn 1/2 ton status Premium Member

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    I did have some issues but I was able to spin it to line up for the pin. It was kind of tight though. I did grind a little bit on the bottem/square side of the center blocks because they wouldnt slip in to the outer spool, past the ring gear. I took off just enough material on one edge so they would slip in.

    I thought I was going to have to grind on the rounded outside edge to get the blocks to line up. But then I noticed that the axle shafts and clips were not seated all the way in the outer halves of the spool. So I went and pryed the axle flange out a bit and that pulled them in enough. Then I was able to drop the blocks in further. Then I was able to rotate them and line everything up. Hope that helps.

    Z
     
  19. 55Willy

    55Willy 3/4 ton status

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    tried all of that with no luck. I'm just gonna weight til it is under the buggy and just use the driveline and brakes to spin it.
     
  20. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    In the original write up it states that the cast rotors are too thick...but this version in this thread shows the cast rotor hats instead of the stamped steel rotor hats. I can't find anything but cast rotors here localily. Do you have any trouble with lug nut length with the slightly thicker cast rotor hat? What style of wheels do you use? aluminum or steel?
    Thanks,
    Blake
     

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