Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Has anyone built up a 12 bolt and not had it break?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by bigwheels6, Feb 4, 2001.

  1. bigwheels6

    bigwheels6 Registered Member

    Joined:
    Jan 30, 2001
    Posts:
    6
    Likes Received:
    0
    I've asked a little bit about what can be done with a 12 bolt, and the general feeling is that swapping it out is the best way to go. Has anyone tried putting in stronger axle shafts or high strength ring pinions? I'm hoping that someone has actually had a 12 bolt work without breaking. If anyone has had good luck with one, please let me know how.

    In every contest there must be a loser.
     
  2. k5king

    k5king 1/2 ton status

    Joined:
    Jul 23, 2000
    Posts:
    571
    Likes Received:
    0
    Location:
    Parkesburg, Pennsylvania
    i am currently working on my rig and it has a 12 bolt in it,,,i have installed a detroit locker,4.56's,new seals and bearing's,,and put in some gm replacement axles for now,,,i don't do any crawling so i think the axles will be ok for a while but i am going to replace them later with a nice set of moser axles... just look at drag racing for instance,,,lot's of theose guy's are using the 12 bolt's in very high horse power car's...
    i think that a good set of axles is the key to wether or not it will hold up,,,but if you are going to be doing extreme crawling all the time i would say upgrade to the 14boltFF....i would but at the time none were available to me so i just built my 12 bolt up to bomb proof specs[​IMG] it should hold up for all the mudding i do,,,unless i start making weekend trip's to paragon,,,then i'll be doing the 14bolt swap....
    hope this eases you r nerves some[​IMG]

    ANYBODY LOSE THEIR JEEP????????[​IMG]
    I JUST FOUND ONE UNDER MY BLAZER!!!![​IMG]
    [​IMG][​IMG]
     
  3. thatK30guy

    thatK30guy 1 ton status Premium Member

    Joined:
    Jan 12, 2001
    Posts:
    32,076
    Likes Received:
    55
    Location:
    .
    Why not check into Warns full floater kit? Steve Watson ran it on his Blazers rearend, too. This just converts the semi to a full floater. The kit even includes new shafts and everything to change it over.
     
  4. bigwheels6

    bigwheels6 Registered Member

    Joined:
    Jan 30, 2001
    Posts:
    6
    Likes Received:
    0
    I think that I'm going to look into some of the drag racing aftermarket stuff. As best I can tell, they run the same 12 bolt the truck has. I just don't like the idea of giving up ground clearence.

    In every contest there must be a loser.
     
  5. 90K5

    90K5 1/2 ton status

    Joined:
    Jun 1, 2000
    Posts:
    3,719
    Likes Received:
    0
    Location:
    Lubbock, TX
    How big are your tires? I am running 33s on a 10 bolt, but I'm going to a 14B SF this summer mostly for the 4.10 gears (i have 3.42s now) I don't think you will lose very much clearance with a SF at all, and they are supposed to be 50% stronger. I was also thinking about going to a 12 bolt rear, but since the prices should be pretty clsoe for both of them, and the 14 is stronger, i'd go for it. If your 12 bolt is in good, shape, i'd probably build it up IMHO

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  6. achuskies69

    achuskies69 1/2 ton status

    Joined:
    Jan 7, 2001
    Posts:
    229
    Likes Received:
    0
    Location:
    Raleigh, NC
    Warn is discontinuing the axle kits along with the Black Diamond suspension systems...i dont know how much longer they will be offered but they had an article in FourWheeler magazine bout them getting rid of the stuff...


    <font color=orange> if you cant beat 'em, drive over 'em </font color=orange>
     
  7. FWP

    FWP CRS

    Joined:
    Oct 11, 2000
    Posts:
    3,845
    Likes Received:
    3
    Location:
    Prescott Valley, AZ
    Mine's been workin for 2 years on my shortbed with 35s. Granted, I do not go crawling over 4 foot boulders or 4 foot deep mud pits. But for general average wheeling, it works for me!

    [​IMG]
     
  8. Thumper

    Thumper 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,582
    Likes Received:
    0
    Location:
    Alberta Canada
    I run a 12 bolt in mine with 35s, a 325 hp motor, and I have never broken a shaft. But as they said, I dont do any crawling, mostly mud.
    Good luck

    Mike


    <font color=blue>Thumper
    85 Fullsize Jimmy
    [​IMG]
    <font color=red>Lets Go Wheelin! </font color=red>
     
  9. Donovan

    Donovan 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    524
    Likes Received:
    0
    Location:
    Arvada, CO
    The best way to keep your 12 bolt together is to use new steel caps and replace the stock ones. You really need just one of them and install it on the drivers side. This will keep the ring gear from deflecting. A good set of axles would be a great idea to. http://www.rustbucket.coloradok5.com
    Bigger is Better
     
  10. BurbinOR

    BurbinOR 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    5,829
    Likes Received:
    0
    Location:
    Oregon
    Great info Donovan. Your point about the spool..... hmmmmm...........with some good axles and the steel cap...............think a spool would be better than a Detroit? Talk to me.........this is sounding better and better to stay with a 12 bolt.

    <font color=orange>'79 - 406 TPI -<font color=orange> K5#5 - <font color=blue>See it at---&gt;<A target="_blank" HREF=http://www.blazzinor.coloradok5.com>http://www.blazzinor.coloradok5.com</A>
     
  11. '73 K5

    '73 K5 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,763
    Likes Received:
    0
    Location:
    Kansas
    Actually the 12 bolt car axles are different than the truck ones. So don't mix and match them. Anyways I've got my 12 bolt beefed up just about the way I want. My Blazer isn't done enough to go offroad yet, but at least the rearend is ready. I kept it for the light weight and no ground clearance problems.
    --I replaced the studs for the lugnuts with Moser Grade 8's.
    --Put in the Moser alloy axle shafts.
    --U.S. Gear, 4.11 ring and pinion gears.
    --All new bearings and seals.
    --Eaton limited slip diff with carbon fiber clutch discs, and had West Coast Differential install a more aggresive spring (800 pound)
    --Replaced the stock hardware for the main bearing caps with an ARP stud kit.
    --Got a T/A Performance diff cover with the girdle supports for the main bearing caps.
    All of that eliminates pretty much all the weak parts. I'd feel safe with up to 36's on my 12 bolt, but since I'm only running 33's it should hopefully last for a very long time.

    '73 K5
    Chevy good...Ford bad
     
  12. blazer72

    blazer72 1/2 ton status

    Joined:
    Apr 13, 2000
    Posts:
    939
    Likes Received:
    0
    Location:
    KCMO
    First Warn IS NOT stoping the axel, Both Steve Watson and I have Talked to them about this. I do hear from many that they heard it from a friend that Warn was going to stop makeing the axels but there not. Why would they? They cant make them as fast os there being bought up.

    My 12 bolts were easy to kill up till the time I installed the floater kit. The kit pulls all the side loads off the diff. Meaning that the diff bearings no longer support any of the load. If you were setting sideways on a hill the wight of the truck is trying to pull the uphill axel out this load is placed on the diff bearing set though the c-clip. With the floater kit all of this load is gone. Its now on the wheel bearing which are 2 to a side not 1. Every thing runs cooler too. And since the floater kit removes some of the side to side play it handels a bit nicer too.
     
  13. klier

    klier Registered Member

    Joined:
    Jun 19, 2000
    Posts:
    88
    Likes Received:
    0
    Location:
    Faribault, Minnesota
    Hey '73 K5:

    Do you have an itemized price list for axle upgrades such as the ones you did? I am planning on at least swapping gears in the future (stock gears SUCK with 33s!). Any other info or advice you can give would be great too! When going from stock gears to 4.11s, what else is necessary to replace/upgrade at the same time?

    Thanks!

    Brian Klier
    '86 K5 Blazer
    [​IMG]
     
  14. Donovan

    Donovan 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    524
    Likes Received:
    0
    Location:
    Arvada, CO
    I made several calls today and you can get 12 bolt spools for trucks. Tom's differential had a 33 spline for $187 and he was out of the 30 spline truck one. Next I called Randy's Ring and Pinion and they had only 30 spline truck spool and it was $230. Then I called Moser and they could make either 30 or 33 spline in a day or two. These are truck spools and not car spools.

    Donovan
    <A target="_blank" HREF=http://www.rustbucket.coloradok5.com>http://www.rustbucket.coloradok5.com</A>
    Bigger is Better
     
  15. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Summit has Mini spools for the 12 bolt for about $120..
    Dont use a full spool with a 12 bolt unless you can still use your c-clips with it. Dont run a C-clip eliminator kit for off-road as it is actually weaker than the c-clip mounting.

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; <A target="_blank" HREF=http://emmett.coloradok5.com>http://emmett.coloradok5.com</A>
     
  16. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    I have been running a stock 12 bolt with Richmond 4.10 gears for about 2 years now. I use it on many terrains and haven't had any problems yet. I do have a light right foot though...

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; <A target="_blank" HREF=http://emmett.coloradok5.com>http://emmett.coloradok5.com</A>
     
  17. Brady

    Brady 1/2 ton status

    Joined:
    May 6, 2000
    Posts:
    628
    Likes Received:
    0
    Location:
    Parachute,Co
    I have been running a 12 bolt for years first in a Sub then in the Blazer I use now.I swapped the 12 bolt out of the Sub into the Blazer and ran it for a year in that.I had to rebuild a new one when the pinion bearing let loose in the old one.I had stage west put new gears and carrier bearings in it then I put new axle bearings in it and the Detriot E-Z Locker back.That has been the only problem I have had.I use my rig for wheeling only on rough trails(Moab to Holy Cross City and snow busting with chains on the back.I am thinking of going to a 14 boltFF though so I can run some Biggg Swampers.Brady

    '73Beautiful Disaster <A target="_blank" HREF=http://beautifuldisaster.coloradok5.com>http://beautifuldisaster.coloradok5.com</A>
     
  18. '73 K5

    '73 K5 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,763
    Likes Received:
    0
    Location:
    Kansas
    Hey klier. Here ya go.
    Moser axles: 225
    Diff. cover: 160
    ARP stud kit: 20
    Studs: 20
    Bearings and seals: 30
    Ring and pinion install kit: 90
    Eaton LSD: 375
    Spring mod. for Eaton: 62
    Ring and pinion gears: 160




    '73 K5
    Chevy good...Ford bad
     
  19. EDdaTREE

    EDdaTREE 1/2 ton status

    Joined:
    Feb 18, 2000
    Posts:
    1,253
    Likes Received:
    0
    Location:
    Austintown, OHIO
    I ran a 12 bolt with 3.73's and 33 inchers in hardcore mud for 2 years on low maintenance before discovering that there was a Gov-Loc back there. Mine's been almost rolled, buried past the frame, and pipes underwater. The pinion bearing finally gave up...from being full of mud instead of gear oil. I tossed in another 12 bolt 3.73 and am happy with it, soon going to 35's.

    "I'm not stuck...I'm just being as ONE with nature"
     
  20. 6.2Blazer

    6.2Blazer 1/2 ton status

    Joined:
    Feb 24, 2000
    Posts:
    4,675
    Likes Received:
    26
    Location:
    Ohio
    Yeah, I know it's not a 12-bolt, but I've had good luck with my built 10-bolt (same basic design, just slightly smaller). It has 30-spline alloy axles (the same size as the 12-bolt shafts), 4.10 gears, Detroit Tru-Trac. I ran about a year with 33's and then the last year with 35's. The truck is strictly a weekend trail toy which gets to a trailride about once per month. I've broken body mounts, front axle u-joints, been stuck up to the headlights but have had no problems with the rear 10-bolt so far. I do plan on swapping to either a sf or ff 14 in the back in preparation for some bigger tires (37" or bigger).
     

Share This Page