Chevy LBZ Duramax Diesel UpgradesPosted in How To: Engine on September 2, 2014 Comment (0)
General Motors makes a great heavy-duty truck, with the Duramax engine rivaling the legendary Cummins for power potential and the Allison transmission in a league of its own. That said, there is always room for improvement. GM trucks sit lower than the competition, and the independent front suspension brings its own unique set of challenges when running bigger tires.
We recently added 10 modifications to this early ’07 (classic body style) LBZ Duramax powered crew cab, short bed Silverado 2500HD to give it a complete makeover. The truck already had a Rough Country 4-inch suspension lift and free-flowing BD Diesel exhaust when we brought it home, but we are counting them on our list because we consider them some of the first modifications you should make (the truck’s previous owner must have agreed). Our Silverado was one of the last of the trucks offered before Diesel Particulate Filters (DPFs) become mandatory by EPA law, and as such it is highly desirable and has really retained its value. We plan to keep the truck for a long time and have no issue making an investment in the Chevy, but we wanted a lot of bang for our buck.
We wanted a lot of bang for our buck
This Silverado gets used as a tow rig and chase vehicle for desert racing, as well as a daily driver, so it is subjected to a wide variety of environments. The goal was to make the truck more capable on-road and off-road while standing out from the sea of stock trucks. And we wanted to do so without sacrificing mileage, ride quality, or towing ability. A tall order for certain, but with careful selection of components we were able to accomplish our goals.
Top 10 Upgrades
• Tie rod sleeves
• Pump rub fix
• Lift kit/upgraded shocks
• Bigger tires
• Driver-side exhaust manifold
• Free-flowing exhaust
• Auxiliary fuel tank
• Additional lighting
• Side steps
The factory tie rods on GM trucks and SUVS leave something to be desired. Add larger, heavier tires and wheels and you are asking for trouble. Fortunately Rough Country makes a bolt-on solution that is affordable and easy to install, but you do need to have the truck aligned after adding the tie rod sleeves.
The NP261 transfer case in our Silverado uses a magnesium case with an aluminum pump to circulate gear oil. The problem is that the pump is made from a harder material than the case and can rub right through the case, allowing the fluid to leak out. Left unchecked, spectacular carnage can result. Adapt-a-case makes a steel wear plate for the transfer case that prevents this. You have to pull the case and partially disassemble it to install the wear plate, but it is cheap insurance compared to replacing a transfer case. We pulled the case and Bayshore handled the installation of the parts for us.
Our Silverado had a 4-inch Rough Country lift installed when we purchased the truck, and the lift kit has served us well. We did take the opportunity to upgrade to Fox 2.0 Performance Series shocks with remote reservoirs for greater shock damping with the larger General tires. The aluminum Fox shock bodies will never rust and the added volume of the remote reservoirs keep them from heating up and fading on long washboard roads.
We were tired of our Silverado looking like a 2WD truck, but 35-inch General Grabber AT2s on black Method rims solved that issue. The Grabber AT2s are more aggressive than the average all-terrain and have generous tread depth, but they are also quiet on the street and provide excellent grip in snow and rain. Perfect the variety of duties that our chase truck/tow rig/daily driver is subjected to.
General offers the Grabber AT2 in dozens of sizes ranging from 27 inches tall to the 35s that we chose for our application. The D load range is less than the Load Range E tires we replaced, but the unladen ride has improved as a result. These Grabber AT2s have a Max Load of 3,000 pounds per tire, so we aren’t worried about overtaxing them when towing a race truck on a trailer.
The larger diameter of our 35-inch General Grabbers meant that the spare tire no longer fit under the truck. Fortunately this truck is equipped with a lockable chase rack. Titan Fuel Tanks has an elegant solution for that new real estate under the bed in the form of a 30-gallon Spare Tire Fuel System. This is what we call turning lemons into lemonade. It fit perfectly with our theme of “no compromises.”
The Titan Spare Tire Fuel System is a transfer tank that uses a low pressure pump to move fuel into our factory fuel tank. Titan leaves the filler mounting up to the installer. Samco Fabrication added a second fuel door to the back of our truck, but you could add a filler to the bed or inner rear wheelwell instead.
The Edge Juice with Attitude CTS features plug-and-play installation and allows you to switch tunes on-the-fly from six different power levels. The bump in power helped to offset the larger, heavier tires that we added and has provided a noticeable improvement in fuel economy, even when towing.
The Edge Juice with Attitude CTS can display up to eight values at a time and lets you decide from dozens of parameters to monitor your engine’s vital signs. One of the included options is a speedometer, which was helpful with our larger tire size and particularly useful on this era of Chevy, which is notorious for costly speedometer issues.
The factory driver-side exhaust manifold on ’01-’10 Duramax engines is pinched down to allow for steering shaft clearance, but there is plenty of space between the manifold and the steering. BD Diesel offers a bolt-on solution with a ductile iron replacement that provides full exhaust flow, removing the restriction from the front two cylinders.
As a bonus, the BD exhaust manifold is already tapped for a pyrometer so we could display our exhaust gas temperatures on the Edge Juice monitor. The Juice even allows you to set up a warning at a user-defined temperature and will automatically back off power if the EGTs climb too high.
We chose bolt-on products that limited downtime and expensive installation since this truck is used as a daily driver. Samco Fabrication handled all of the installations on our Silverado and did a clean job routing all of the wiring for the various electronics. The Titan fuel tank was the most involved of all the products, but it was well worth it for the added fuel range.
Since our chase truck spends a lot of time in the desert at night, lighting was a priority. KC has been synonymous with off-road lighting since the ubiquitous Daylighter. We chose a set of the company’s 861 8-inch round HID lights in a long range pattern. The lights came with 50-watt bulbs, removable covers to protect the lenses, and all of the necessary wiring for an easy installation. KC offers HID lights in driving, fog, and flood patterns, as well as LED and halogen lighting for any situation.
KC’s light bar gave us a sturdy place to mount the 861 HID lights and bolted on in a matter of minutes. The light bar is made in America and mounts to the factory towhook location, sandwiched between the towhooks and the frame. KC has bolt-on light bars for nearly every truck in the market, and they are available in black or chrome finishes.
Samco Fabrication wired the KC lights into the stock foglight switch for a clean installation. Also visible above the brake controller is the monitor for the Titan fuel tank, so you never have to guess how much fuel you have remaining. Samco’s auxiliary tank that mounts in the factory spare tire location is one of those “Why didn’t we think of that?” products.
The last modification we made was the addition of N-Fab side steps to ensure that the whole family can still easily get in and out of our Silverado with the larger General tires. Our factory steps were beat, and we were looking for a stronger solution that was easy to install and didn’t break the bank. These wouldn’t be a good option for a truck that goes rockcrawling, but they met all of the requirements we had for this particular truck.
We accomplished our goals with increased power, a more supple suspension, improved fuel range, stronger steering, more traction, and better lighting. The final product works wonderfully as a daily driver and is very capable as a tow rig and chase truck in the desert.
Next 5 Upgrades
If You Tow More
• Deeper transmission pan
• Transmission cooler
• Fifth wheel/gooseneck hitch
• Exhaust brake
• Rear airbag helper springs
If You Wheel More
• Solid axle swap
• Locking differentials
• Front bumper