Have you seen the commercials where the guys are driving their Chevy Avalanche and they stop and decide to change? We got the opportunity to do just that. This year for our Ultimate Adventure we snagged a brand-new 2003 Chevrolet Avalanche 2500, and we are going to change it in ways that even the General hadn't planned on.
The Chevy Avalanche is kind of an odd vehicle. It's like a Suburban without the back, or a Crew Cab truck with no separation between the bed and cab. Plus it has the added benefit that the rear seats can fold down and you have access to the bed from the cab. This feature is great if you need to haul plywood, but not if you are hauling horse manure or your prized piggy to the fair. These trucks are known for their unique styling and the plastic body cladding that evokes a "love it" or "hate it" response from most people who see it. We were pumped to get our hands on this rig because it was one of the last vehicles that we would have chosen to build into a serious trail rig, but a very capable project truck to start with. Plus, we liked the challenge of trying to make a cool-looking and more capable rig from an odd duck.
As you may know, Ultimate Adventure is sponsored by some great companies such as BFGoodrich, Tuff Country Suspension, Dynatrac, Detroit Locker, Rhino Lining, Warn, Poison Spyder Customs, Trailready, and Flowmaster. These companies are just some of the sponsors and usually send a representative on our adventure with us, but we also like to find smaller businesses as well to test out their components on our trip. In the end we apply some of the coolest components from companies all over the nation to build what we think will be the Ultimate vehicle for our Adventure, but we also like to push the envelope and try new and unusual ideas that are not seen on the trail every day. We think you'll be excited with what we end up with.
From the time the buildup started to the day it hit the trail was one and a half months, and in that time we went from a barely broken-in new rig (1,700 miles) to a machine unseen before. Every year we take a select group of sponsors, readers, and staff on our Ultimate Adventure trip, and this year we are going to the muddy tight trails of the Southeast. We will report on how the trip went in our Nov. 2003 issue, but for now let's dive into the first stages of The Change, which took place at Off Road Unlimited in Burbank, California.
To start a project rig you have two choices: start with a pile of parts and assemble it, or start with a complete rig and disassemble. We chose option two, but first we needed a rig. If you are wondering why we would start with a brand-new '03 Chevy Avalanche 2500, consider that it has an 8.1L engine and a 4L85E electronically controlled four-speed automatic. In addition, it comes with disc brakes on its full-floating 14-bolt rear axle, and rear leaf-spring suspension and independent front suspension. Even with all these great things we felt we could change a couple of them for the better. | 
Tearing apart a perfectly good, brand-new truck is a lot of fun. Most people don't get a chance to do that, and we wish we could share the fun with all of you, but since the shop space at Off Road Unlimited would be way crowded with a few hundred thousand readers, we decided instead to show you a few pictures. John Hughbanks tore off the independent front suspension, which we will change for dependable leaves from Tuff Country. |
Ryan Sanders also got to beat the parts out of the piata by tearing out the exhaust. Some of the pipework might get reused, but with some Flowmaster parts to boost it. To make room for progress in other areas, we pulled the whole thing from the manifolds back. | 
After Hughbanks unbolted everything from the front and chucked the parts in a big dumpster, Mauricio Natera fired up the big red wrench to clear out some brackets that were still cluttering up the frame. |
With the disassembly under way it was time to head down to Huntington Beach, California, to see what Dynatrac Axles had in store. Once again, Dynatrac agreed to build an ultimate axle for our Ultimate Avalanche, but this year we went a step further. In addition to one of its super high-clearance Pro Rock 60 high-pinion front axles, we also brought home a standard-rotation rear Dana 60. Now, you may ask why we pulled a perfectly good 14-bolt with disc brakes to swap in a 60. For the answer, you'll have to keep reading. | 
Maurice Rozo, the owner of Off Road Unlimited, even let this knucklehead cut some parts off. This guy was fresh off the farm, and he usually spends his time writing articles for a 4x4 magazine, but was in hog heaven when he got to use a cut-off wheel and air chisel to remove the rear spring shackle hangers. The others guys in the shop were less than excited since an air chisel in the hands of a novice is very, very loud. |
To fill the housing, turn the wheels, and keep power to the tires on the ground, we enlisted a set of the always-faithful Detroit Lockers from Tractech. This is the old standby for locking differentials, and we were ready for something we could put in the housing and just forget about. Around the Detroits we bolted a set of 5.13 gears from Randy's Ring and Pinion. Since we are running such a big engine and are planning on tires that will be knocking on the 40-inch door, this ratio should be just fine for highway and trail cruising. | 
If you have never seen an axle being built from scratch with all new parts, as Dynatrac does, then you have missed out on a cool array of technical wizardry. Being into machines and metal and all that stuff, we had a blast watching the Dynatrac crew put our 60s together. The first major step involves a bunch of measuring and math to figure out lengths of axletube, shafts, and parts so that each piece fits together perfectly. Our front axle has the same dimensions as a '79 Ford front 60 with a 69 3/4-inch wheel-to-wheel mounting surface. |
Then the machine work starts on the tube with Dynatrac's stronger, properly forged (not cast), tube forks welded on and the tubes turned down so that they are ready for oil seals and to be pressed into the cast-nodular-iron differential housing. When the tubes are ready they go into a press and get stuffed with up to 1,500 psi of pressure. Even a very tight fit will move under that type of load, and the press doesn't stop until the tubes are seated. | |