Steve Johns 6.2L Diesel Hummer H1 - 2

Volume 1 Issue 4 - Diesel Articles

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Steve Johns 6.2L Diesel Hummer H1
Central Tire Inflation System
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Central Tire Inflation System

Adjusting tire pressures for off-highway traction (usually much lower than street PSI) is a common and very effective driving technique. Having the perfect air pressure for the conditions and putting as much rubber on the road as possible are primary elements of traction. The biggest negative to airing-down for off-highway travel is the need to air-up before driving at speed on pavement. Most off-roaders solve this problem with one of the many 12-volt compressors sold for this purpose, using either a portable unit or one permanently mounted to the truck. But the airing-up process can take a half hour or more depending on the tires and the compressor. For many enthusiast-level compressors, filling a tire like the H1’s 37-incher will cause them to overheat and quit before all four tires are filled.

The optional Central Tire Inflation System (CTIS) solves these problems and a few more. Instead of exiting the truck and slowly bleeding air from the valve stems, the CTIS allows the driver to deflate or inflate the tires on-the-fly. The CTIS includes an inflate/deflate switch as well as a rotary selector to choose either the front or rear tires only, or all four. Having the ability to fine tune the tire pressures from the cab is a great feature. As someone who often adjusts his tire pressures both on and off-highway depending on the load, I would love to have this option on all of my trucks.

The compressor is mounted under the hood, and has a coupler allowing the attachment of an air hose to fill trail companions’ tires or any other compressed air need. Steve has even used his on-board compressor to fill bicycle tires and inflatables when visiting nearby lakes. Some have reported problems with the CTIS. Steve’s system was serviced by his dealer before he purchased the Hummer and he’s never had a problem with it.

Central Tire Inflation System

Jeeps taste like chicken bumber sticker 8 a Jeep License Plate

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War Stories

About two weeks after purchasing the Hummer, still sporting temporary dealer plates, Steve joined the Nor Cal Hummer Group’s Sierra Snow run in the nearby Sierra Nevada mountains. After a few hours of easy snow driving, Steve failed to make it up a slight grade because he didn’t know how to use the brake-throttle-modulation technique to get the Torsen axles to hook-up. As the third H1 in a line of vehicles Steve quickly found himself stuck and blocking the trail. He had never owned a truck with a winch before and had no idea how to use one properly. Under the tutelage of more experienced members, he used his winch for the first time and easily extracted himself with a 30-foot pull. A few hours later, Steve again used his winch to pull out the ’00 H1 Hummer Wagon in front of him that had slid off the road and was stuck in a few feet of deep snow.

Steve’s slightly embarrassing worst stuck story involves a little mud puddle and his son Trent. Spotting a mud puddle in a construction area very close to their home, Trent said, “Daddy let’s go play in the mud puddle.” Steve obliged and drove off the road into the puddle. The puddle wasn’t enough for Steve and he ventured out into the field of mud for a little more play. After a short frolic, Steve turned around and headed back to the road. He started losing momentum and speed and soon found himself at a stop and very stuck. The clay-like mud was caked in the tires and packed under the truck; it even covered the bottom of the doors. Steve called a friend with a modified Chevy Blazer to pull him out. While waiting, Trent and Steve were offered help from a passing stranger driving a lifted, late-80s short-box Chevy pickup. Using Steve’s chain the little half-ton was not able to recover the beached H1. When Steve’s friend arrived he was impressed saying, “Steve, you’ve done it right my friend.” The full-sized Blazer tried but was also unable to pull the Hummer from the mud’s grasp. Both of these Chevys were heavily modified, sporting strong engines and mud tires, but they proved to be no match for the mud. With nightfall coming and headlights already on, the H1 was finally recovered after chaining the Chevy pickup and Blazer together, providing a sufficient anchor for Steve’s 12,000-pound winch to pull the Hummer free. It took Steve several hours, over two days, to remove all the mud glued to the General.

Steve Johns and his son, Trent

6.2L Diesel Hummer H1 6.2L Diesel Hummer H1 6.2L Diesel Hummer H1

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Novice Test Drive

While on the trail ride for this photo shoot, Steve offered me the driver’s seat on one moderate hill climb. I have lots of saddle time in full-sized trucks, but looking out over the wide AM General H1 hood was a new experience. Getting the torque biasing Torsen differentials to hook-up using the brake-throttle-modulation technique proved challenging. I’m accustomed to traditional limited-slips, full lockers, and electronic traction control. I was either spinning tires or not moving forward. I then watched Steve drive up the same obstacle without spinning a tire. Apparently, he has mastered the technique!

Not Giving Up on the 6.2L

Steve regularly travels from his home in Reno, Nevada for Northern California Hummer events and to play with his Cool, California High Mobility 4x4 friends. Several times a year, Steve ventures into the deserts of Nevada, a perfect playground for the wide H1. At one time, he considered selling his Hummer, but couldn’t bring himself to part with the beast. He enjoys it too much. Despite the engine’s shortcomings, the H1 and the 6.2L diesel are a strong marriage and continue to work well. Steve and Trent are looking forward to racking up thousands of miles over the coming decades.


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Comments (1)add comment

Gottfried said:

UN Consul in Honduras
Thank you for sharing, beautiful Hummer you got....I have a 2003 H1
here in Honduras, got new tires but no balancing possible with CTIS
HOW CAN THIS BE DONE,please help !
Thanks and greetings from Honduras,
November 17, 2010
Votes: +1

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