Lifting A 2015 GMC Sierra To New Heights
The life of a truck can be hard. Most spend their time busting their beds hauling heavy loads, having their suspension abused by ruts and potholes, paint blasted by salt or gravel, and then driven home to be left outside in the elements like a dog in the yard. Some trucks have all the luck though. They get to be driven off the lot new, destined to become a show truck and be ogled by masses of onlookers at custom truck shows, never having to put in a hard day's work. When a truck is headed for the high life there is usually a long list of modifications that will be done before rolling into the show and having a crowd gather.
One thing was certain in this build early on: It needed to be substantially higher than stock. When the overall look was mapped out and agreed upon, this pre-show truck was sent to Devious Customs in Riverside, California, to have an altitude adjustment by their extremely capable hands. A 6- to 8-inch lift kit was ordered up from CST Suspension, which would give it just the right stance and ride height before a host of upgrades were installed. The kit came with all the necessary parts to lift our Silverado, all powdercoated black, including a massive one-piece gusseted subframe, steering drop down centerlink, and 2.0 emulsion shocks. Even with all the changes, this tough and well-designed kit still retained the factory track width. The truck also received a set of red letter General Grabber 35x12.5R20 tires featuring an aggressive tread pattern and a set of gloss black and machined RBP 89R Assassin Wheels as part of the full-scale build with Devious.
The Devious crew was going to then tear the Sierra apart to bring it back up in a different form for Tough Country where it was debuting at SEMA to showcase their line of bumpers, side steps, headache racks and lightbar mounts this past year and at the time was one of the first '15s to receive such a lift. Follow along as we dive deep into this lift installation to show how an all-inclusive kit can turn a task into a breeze.
1. The complete kit from CST included everything needed to lift this Sierra up, including the subframe, spindles, steering centerlink, diff drop brackets, bumpstop brackets, front skidplate, rear lift blocks, U-bolts, rear brake line bracket and all necessary mounting hardware.
2. Putting the stock truck up on the lift was the first step; it got raised to a workable height and all four wheels were removed.
3. We unloaded the tension on the torsion key with a removal tool and unscrewed the adjustment bolts. Then, the retaining block was removed and the torsion bars were ready to be slipped out.
4. Next to be taken out was the torsion crossmember, as it will be relocated later. The two bolts on either side were removed and the crossmember was able to be dropped out, with the now unloaded torsion bars taken out and marked R and L to be reinstalled later.
5. The Devious crew then turned their attention to the front hub removing the axle nut, the brake caliper, and the brake disc so the rest of the front suspension could be accessed.
6. With the brake caliper safely hooked aside, we were able to unbolt the shock, and disconnected the axle from the spindle. We then removed both the spindle and the lower arm as well.
7. With the axle now free and hanging, the six bolts were removed and we were able to remove the axle from the front differential. We repeated that process on the passenger side to free up the differential.
8. The rear crossmember had two bolts on either side, which were quickly removed to be replaced by the supplied one from the kit.
9. With the diff ready to come out, the driveshaft was separated and was left to hang while good ole' brute strength safely lowered the diff out of the way. The four hands of the Devious crew stood in for a transmission jack, but it can be changed alone if one is available.
10. Using the supplied pattern that came with the kit, we then cut out a section of the driver-side lower arm mount, carefully noting that the front side of the mount gets more material removed.
11. Both the passenger and the driver side get a diff lowering bracket, with the CST logo facing outwards. We were now ready to put the diff back in using the new bolts from the kit and tightened it back into place making sure that it did not hit the frame where the driver-side mount was cut. It was adjusted a little to the passenger side before everything was tightened up.
12. Team effort was utilized again to install the trussed steering centerlink, making sure that the tabs were facing the front of the truck. A transmission jack could also have been used when working alone, but the buddy system works just fine if one is around.
13. Adding Loctite to the bolts of the subframe, it was muscled in place.
14. The factory bumpstops were then installed to the bumpstop brackets from the kit first using hand power to twist them on, then a ⅜-inch bolt to attach them to the pocket where they used to go.
15. Bolting up the axles to the differential, the installers then bolted the lower arms back into place leaving the bolts on the arms a little loose to be tightened up when the truck is back on the ground to avoid wear on the bushings.
16. The dust shield on the back of the hub had to have an approximately 2x2 triangle cut off the end of it; we made short work of it with a cutoff tool.
17. The stock spindle was then removed so the CST spindle could be attached to the hub with four new bolts from the supplied hardware bundle.
18. Now the hub assembly could be reattached, bolting it to the upper and lower arms, and we also fed the axle through so the axle nut could be tightened back up.
19. With the hub assembly in place, attention was turned to the front shocks, which received an extension bracket, making sure to rotate the bracket so the open side faced the rear, and then the shock was bolted into place in the upper and lower shock mounts.
20. The steering tie-rod ends were next on the list and were bolted back into place on the factory location of the front spindles.
21. A set of drop mounts on either side the torsion crossmember then received 1-inch bolts that were dabbed with Loctite and bolted into place.
22. Two holes were drilled directly in front of the torsion crossmember for the torsion side plates.
23. The torsion side plates were bolted up into their location on either side of the torsion crossmember.
24. Then, we slid the torsion bars in place and slipped the keys back on as well. Using the torsion key tool again, we adjusted them back to the stock position and installed the adjustment bolts.
25. After the torsion bars were set into place, the front skidplate was installed using the supplied hardware from the kit.
26. Turning our attention to the rear, we set the truck on the ground and unbolted the rear shocks.
27. Then, the four U-bolts from the rear leaf spring were unbolted from the axle.
28. With the truck still on the ground, the lift blocks were installed working on only one side at a time. Once each side was in place, both sides were tightened back down.
29. With the lift block installed, the rear shocks could now be bolted up.
30. The brake lines were then unbolted from the axle to be attached to the lift brackets, which received a new set of bolts from the kit, which then installed to the stock bracket using the old bolts.
31. The truck was then raised back up to have the torsion keys tightened up to have a little more lift, but we left it at a safe level to give it approximately 1 inch of droop for a little comfort and to err on the side of safety.
32. All of the front suspension components were then inspected and torqued down, and the hubs were turned side to side to make sure the brake lines and ABS lines were in safe locations and did not get pinched or strained.
33. Our newly lifted GMC received a set of RBP Assassin eight spoke wheels finished in gloss black and machined finish along with a set of aggressive General Grabber 35x12.5R20 tires complete with red letters to mount to them.
34. This now completed '15 Silverado was decked out with Tough Country bumpers front and rear, side steps, headache rack and a lightbar mount. It was debuted at SEMA 2014 and was a finely crafted machine that drew attention the entire show. Check out the CST website to see what's available for your truck.