Does Detroit TrueTrac come stock on 14 bolt diffs?

Discussion in 'GM Powertrain' started by BillM, Feb 28, 2012.

  1. BillM

    BillM Rockstar 100 Posts

    Does anyone know if the Silverado 14 bolt diffs came stock with Detroit TrueTrac. I would like to upgrade my Tahoe to a 14 Bolt TrueTrac, and I thought that I could get one from the junk yard and modify it for my 2003 Z71 Tahoe. Thanks.
  2. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    As far as I know, the only differential types offered from the factory are open diff or the Eaton gov lock (G80).
  3. Boonduff

    Boonduff Rockstar 4 Years 100 Posts

    MrShorty's right.
  4. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    A Detroit locker came in 14 bolts that were put in military trucks, but that's it. Like MrShorty said, trucks equipped with the G80 option have eaton limited slip lockers in them. If you have a 10.5" 14 bolt axle, the Detroit locker is cheaper than your average locker because it doesn't require a new carrier.

    Your Tahoe doesn't have a 14 bolt in it, does it? 14 bolts were only put in 3/4 and 1-ton trucks, and depending on the 3/4 ton truck, it may have had either a 9.5" semi-floating 14-bolt or a 10.5" full floating 14-bolt.
  5. BillM

    BillM Rockstar 100 Posts


    Yes, the Tahoe comes with a 10 Bolt Diff. The Plan is to get the Silverado 14 Bolt and fit it to the Tahoe. First, I will remove the 10 Bolt, and cut the axle housings off. I will cut the 14 Bolt's axle housings off. Machine the resulting Diff with a press fit sleeve and weld the 10 Bolt's axle housings onto the 14 Bolt's sleeve and Diff. That gives me the 14 Bolt Diff with the Tahoe's suspension. I have ordered Dutchman forged 31 spline axles with the 6 lug bolts for the wheels. I guess that I will have to get a new Detroit TrueTrac. The 14 Bolt came with the Eaton Gov Loc. I am planning on changing the gears on the front and back to 4.56:1. To complete the change over, I will get a Mag HyTech cover. I forgot, I have to shorten the drive shaft, and replace the U-Joints with some new forged ones.
  6. GM-Guy

    GM-Guy New Member

    The G80, is only a designation for a "limited slip" "type" of axle
    My 02 Avalanche had the G80 RPO, which was the gov lock type
    My C5500 had the G80 RPO, which is the torsen type which is closest to the True-trac
  7. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    Wow, that sounds ridiculously complicated. If I were doing that, I'd just stick the axle under the rear and change the fronts out to 8 lug. Either that, or find a semi-float 9.5" 14 bolt from a light duty 3/4 ton truck and drop that under there. It's already 6 lug. Both the semi-float and full-float that did not come from under a dually should be the same axle width as the 10 bolt. Just the spring and shock perches should need to be moved. Either way, you'll either need the driveshaft changed to the 1350 series u-joint or use a trick u-joint to do the conversion.
  8. BillM

    BillM Rockstar 100 Posts

    Complicated?? I forgot to mention that I am machining, and welding on new axle housing ends to capture the axle shaft new oversize end bearings in a 3/4 float; or dare I say it on this forum, ford style. It eliminates the "C" clip, in case I run it at the strip. I have gone to far to back out now. It should be unique, to say the least.

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