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Lowering a 2012 GMC 3500 HD with Torsion Keys and Shackles

Baby Steps

Sep 9, 2016
Photographers: Anthony Soos
Some projects get completed in grand style with huge chunks of the needed steps crossed off in short periods of time. Some projects even demand that once a step gets started, it has to be finished. You can’t simply pour a concrete pad and just have the workers walk away to finish tomorrow. A truck project is no different. Bodywork can get completed in steps over time, but once the first squeeze of the paint gun happens, the whole job has to be finished.
This ’12 GMC Sierra 3500 HD dualie project from Devious Customs has not reached those advanced stages just yet. For right now, it is still in the step-by-step area of the build. And as it has not advanced at such a blistering pace, owner Jeff Davy decided to take it slow for the moment and make some small changes before the large-change portion of the build starts to happen.
Photo 2/22   |   2012 Gmc 3500 Hd Sierra Lowering Before
The HD started as a rough and tough shop truck that would tow, haul, and transport the Devious crew to whatever show they choose to roll deep at. After many years of service, though, Davy wanted to give this hard worker a transformation. To complete the first baby step of this ongoing project, he wanted to lower it down a few inches and fit it with some new wheels and tires. To handle the lowering, the discussion turned to the most obvious place with adjustable torsion keys and lowering shackles.
To amp the style factor up a little bit, Davy added a set of 24x12 American Force wheels with 295/35R24 Falken Ziex tires. But in order to see the first step in the transformation, Truckin had to head out to Riverside to Devious and get right in front of where the action would happen. And although the magic show did not last very long, it was easy to see where the DC crew got its reputation. They were able to knock this install out in no time flat.
Photo 3/22   |   2012 Gmc 3500 Hd Sierra Lowering Keys Shackles
1. We will be installing these lowering keys and new shackles. Together, they will bring the truck down a total of 2 inches. It’s all a part of the master plan over at Devious to transform this dualie.
Photo 4/22   |   2012 Gmc 3500 Hd Sierra Lowering Hoisting
2. While the truck was being prepped back at Devious Customs, we went to D.C.’s favorite wheel and tire shop, Gomez Wheel and Tire in Riverside, California. The tire guys wasted no time hoisting up the heavy wheels into the mounting machine and double teamed the tires.
Photo 5/22   |   2012 Gmc 3500 Hd Sierra Lowering American Force Wheel
3. Here, you can see the finished product. Those shiny American Force wheels do stand out and will certainly bring lots of attention and style to our dualie build.
Photo 6/22   |   2012 Gmc 3500 Hd Sierra Lowering Falken Ziex
4. This beautiful matched set of 24x12 American Force wheels with these massive 295/35R24 Falken Ziex tires needed to be laid out together to see just how big and impressive they are. This photographer had to get up on a rickety 12-foot ladder to make these badboys fit properly into the camera frame. You can see the difference between the inner and outer wheels that make up the rear.
Photo 7/22   |   2012 Gmc 3500 Hd Sierra Lowering Devious Crew
5. When we arrived back at the shop, we caught the Devious crew in mid prep. Clearly, they do things a little smarter and wasted no time or effort, lifting the truck with a forklift before sliding in some heavy-duty jacks under all four corners to keep this HD in the air while we worked on it.
Photo 8/22   |   2012 Gmc 3500 Hd Sierra Lowering Davy
6. Here, shop owner Jeff Davy got his hands dirty removing the stock torsion keys with a removal tool and an impact gun. The stock wheels were left on for the moment. The stock keys were removed, as were the adjustment bolts and blocks. We would be reusing the factory hardware when we installed the new keys.
Photo 9/22   |   2012 Gmc 3500 Hd Sierra Lowering Key
7. With the torsion bars unloaded, Davy slid them back a few inches to let the factory key drop out. He quickly installed the new key from the kit and slid the bar back into place to lock them both down.
Photo 10/22   |   2012 Gmc 3500 Hd Sierra Lowering Tightening
8. The stock adjustment bolt and nut plate were reinstalled on both sides. Davy again used the impact to tighten everything down. When the truck is back on the ground, he will be making a final adjustment to the bolts and keys to make the truck sit right.
Photo 11/22   |   2012 Gmc 3500 Hd Sierra Lowering Remove Factory Wheels
9. With the keys all squared away, Other Jeff (as he is known around the shop), got to work removing all six factory wheels.
Photo 12/22   |   2012 Gmc 3500 Hd Sierra Lowering Shackle
10. What can barely be seen here is the pinch weld right above the rear shackle being shaved down with an air-powered reciprocating saw, with a custom-cut blade seemingly shaped just for this purpose. The pinch weld needed to be shaved on both sides.
Photo 13/22   |   2012 Gmc 3500 Hd Sierra Lowering Swap
11. The rear shackle swap was a simple enough operation, but it’s a tight fit back there. We would only be removing the rear shackle at this time, and here, Davy is working on removing the lower bolt.
Photo 14/22   |   2012 Gmc 3500 Hd Sierra Lowering Shackle Comparison
12. When the two shackles are compared, the difference in size is immediately evident. The new shackle has two installation holes to adjust how much drop is desired. For this install, we went with 2 inches and used the top hole. The new shackle was then installed.
Photo 15/22   |   2012 Gmc 3500 Hd Sierra Lowering Reinstall Bolts
13. With a few curses and some hammer blows, the stock shackle mounting bolts were reinstalled and tightened down. Since no other adjustment is required here, unlike the keys, we tightened up the mounting hardware as much as needed.
Photo 16/22   |   2012 Gmc 3500 Hd Sierra Lowering Lugs
14. Now the rear suspension was taken care of, we turned our attention to the wheels. These new American Force wheels were big and beefy that’s for sure, but the main difference is they are 10-lug instead of 8. These handy adapter plates from AF will do the trick to get our HD that big-rig style.
Photo 17/22   |   2012 Gmc 3500 Hd Sierra Lowering Plates
15. All it takes to mount up these adapter plates is to remove the 10 lug nuts, attach the plates to the existing 8 lugs on the hub, and use the included nuts to lock it all down. Davy attached a plate to the front hub.
Photo 18/22   |   2012 Gmc 3500 Hd Sierra Lowering 24s
16. Now that the adapters were in place on all four corners, the massive 24s could be mounted up. Instantly, our dualie has been transformed.
Photo 19/22   |   2012 Gmc 3500 Hd Sierra Lowering Rear
17. The rear wheels went in the same as the fronts, but the only difference is that there were two on each side, which meant double the work to be done. With all 6 mounted up, our wheels were just about done. American Force also provided these shiny lug covers that were popped on for one final touch of bling.
Photo 20/22   |   2012 Gmc 3500 Hd Sierra Lowering Adjustment
18. With the lugs tight, the truck was placed back on the ground for a final adjustment to the torsion keys. We tightened up the keys using the tag team method of having one person stand at the front and shout detailed instructions like, “Little more on the driver’s side!” The height was adjusted to our liking, and with that, our HD was done and ready to bask in the sun!
Photo 21/22   |   2012 Gmc 3500 Hd Sierra Lowering Sticker
19. Well, almost—Davy installed the most important component of this project, the American Force sticker! Great care and laser precision was used to install this sticker.
Photo 22/22   |   2012 Gmc 3500 Hd Sierra Lowering Finished
20. Wheel gap being what it is, we dropped the truck a few inches, then added a few inches in wheels and tires. All in all, we dropped this truck a total of 2 inches, but that was OK. It was all part of the plan Devious Customs had for this dualie. Keep your eyes planted here to find out what more will be done.


Devious Customs
Riverside, CA 92504
Falken Tire
Fontana, CA 92335
American Force Wheels
Miami, FL 33176
Gomez Wheel and Tire



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