1. With the rear of the truck properly raised on jackstands, remove both rear wheels. Here is a look from above at the right rear corner of the suspension. We will be focusing our attention on the coil springs, lower control arms, shocks, sway bar, and bumpstops. | 
2. Start by removing the shocks. Be sure you have a jack under the center of the rear end. The shock bolts will be much easier to remove if you keep a small amount of compression in the rear suspension. The shock mounting hardware requires a 21mm socket and wrench.
Once the shocks are out, you can lower the rear end and pull the rear coil springs. Pay special attention to the ABS harnesses when you lower the rear. You do not want to stretch or break these harnesses by allowing the rear to drop too far! You will be placing the new springs after a few additional steps. | 
3a. The 5-inch drop we have planned plays havoc with pinion angle and control arm geometry. Fortunately, McGaughy's thought of this and supplies two of these lower control arm (LCA) relocation brackets that correct both problems. Remove the bolt from the rear of the lower control arm and swing the arm down out of the way. You can then place the LCA relocation bracket as shown (3a). Use the supplied spacers in the rear-end mount to prevent crushing when the bolts are torqued to 75 lb-ft. |
3b. This view is looking down at the driver-side LCA mount (3b). Notice the LCA bracket requires an additional bolt to be installed here, which prevents the bracket rotating. You can now repeat the LCA bracket installation on the other side of the truck. Leave the control arm hardware loose at this point. | 
4a. Next, remove both bumpstops. These are retained via a simple interference fit, so just give them firm tug and they'll pop right out (4a). | 
4b. With a hacksaw, cut off the first ring of both stops, as shown, then reinstall (4b). This will allow a bit more suspension travel before the control arm contacts the stop. |
5. Here is a comparison of the stock spring next to a McGaughy's 5-inch drop (inset). You can probably figure which is which. Now you can put the new springs in place, making sure both the stock upper and lower isolators are in place. With both springs standing on the rear housing, slowly raise the jack, ensuring both coils nest in their respective pockets in the chassis. Raise the jack until the springs begin to support the weight of the truck. Now you should go back and tighten the control arms to 75 lb-ft. Doing it in this manner will prevent suspension bind caused by tightening the control arms outside of their normal position. |  | 
6. Here is a side-by-side comparison of the McGaughy's shock and the stocker. Notice the shorter length of the new shock. This will limit suspension sag if the truck is jacked up, preventing the shorter springs from toppling out. Install both shocks. You can reuse the stock hardware for this. |
7. The rear sway bar needs to be moved right to clear the Panhard bar chassis mount. This is done using an offset sway bar endlink (top).
Disassemble the stock sway bar endlinks and loosen, but do not remove the D-bushings. Then, hang the new offset endlink on the driver side, as shown. | 
8. The passenger-side endlink is installed on the outside of its mount with a longer bolt. A spacer is used to prevent crushing the mount when the bolt is tightened. Remove the driver-side D-bushing, slide the sway bar to the right, and install the endlink bolts, but leave them loose for now.
The driver-side D-bushing must be relocated 2 inches to the right in order to clear the bar's curve. There is one existing hole, but the other must be drilled, as shown. You can now reinstall the D-bushing and torque both driver and passenger sides to 50 lb-ft. | 
9. Now is a good time to tighten the endlink hardware. This view is looking forward at the passenger-side sway bar endlink. Notice the tight clearance between the Panhard mount, the sway bar, and the shock. Be sure the sway bar clears both items. If it interferes, readjust as necessary. |
10. After double-checking all fasteners, put the wheels back on and put the truck on the ground. Remember to torque the lug nuts. Take the truck around the block to settle the suspension. Upon your return, you will note the substantial toe-out in the front suspension. Loosen the jam nut and shorten the tie rod end. You can use a scratch awl or a marker to mark one of the wrench flats. This makes it easy to count the number of turns you put into it. This one took nine complete revolutions to get it close. Repeat on the other side and drive it to the alignment shop! | | |
The Final Word
A nice 4/5 drop is the payoff for all of the hard work. The Tahoe now has a nose-to-the-road stance with a bit of remaining rake. You can expect a slightly firmer ride with a very noticeable decrease in body roll when cornering. Remember to verify that all of the hardware has remained tight after 50 miles of driving, and enjoy!