The resulting pattern showed the gears meshed perfectly. | 
Next, the axles went back in, along with the C-clips and the locking pin. |
The Mag-Hytec cover came with its own stainless fasteners and was a direct bolt-on; except for the brake line bracket, which had to be ground down. | 
Aside from having a magnet to capture metal shavings from the fluid and its extra capacity, the Mag-Hytec cover also has a dipstick that makes it easy to check the fluid level. |
For the front suspension, Bill first disconnected both front half-shafts. | 
To drop the front differential, the guys had to unclip the wiring, and unbolt the driveshaft and the Pro Comp drop brackets. |
Since a lot of the front differential assembly was similar, we'll show you the major differences. Rather than having bearing caps, the front differential used two cast aluminum halves that sandwich together to hold the ring gear in place. | 
No shims were used in the front differential, either. Instead, the bearing race was adjusted up and down by removing the retaining ring and turning the threaded center section. |
Just like the front, new bearings were added to the carrier and the new 4.56 ring gear was bolted on with Loctite on all of the fasteners. There's no inspection cover like the rear, but there is a window in the casting that allows you to see the pattern on the ring gear. | 
After adjusting the bearing race slightly, Bill got the correct contact patch on the ring gear and began reassembly. Here, he was checking the bearing pre-load, which he also did on the rear. Everything was within the specified measurements, so the axle was reassembled and reinstalled. |
After test-driving with the new gears, Bill began the Hypertech tuning process. It was as simple as plugging the programmer in, turning the key to "Run," then answering "Yes" and "No" questions. Here, we were selecting the tune for regular fuel. | 
After selecting to increase shift firmness and not modify shift points or the rev limiter, the programming began. During the tune, the truck locked and unlocked the doors, chimed, and flashed messages on the DIC. It seemed possessed, but it took less than 5 minutes to complete. |