2006 GMC HD2500 Duramax, 6-speed Allison tackles the Rockies with a 6/H Cimarron.
Does it look cold? Nice to look at in July! Interstate-70 in the Rockies at Eisenhower Tunnel (11,000ft.) in January. The West side which is 7% grade coming out the tunnel, is a good test of what a truck is capable of. I’m driving a 2006 GMC Sierra SLT HD 2500 now with the Duramax with 360 horsepower and 650 torque right from the factory is addicting. I towed a new 6 horse Cimarron trailer through Eisenhower tunnel in January out the west side in a snow storm and had complete control with the manual switch on the new 6-Speed Allison that let me down shift by pushing a button making the torque converter lockup in each gear as I down shifted electronically not allowing the engine to over rap. It worked like an exhaust brake or a manual transmission. The dash gear selector in “Manual” mode (picture right.) Allowing you to pick any gear like a manual transmission with the same control of a manual tranny. 2006 Duramax HD 2500 and six horse Cimarron aluminum trailer reviews.
New trailer mirrors for 06 are taller with a concave spot mirror replacing the Power Vision as the factory tow mirror. Mirrors are a very important part of a tow vehicle. If I don’t like the factory ones, I change them. And I like both of my mirrors to be the same instead of the “objects appear smaller” right mirror that I throw away. The concave bottom mirror is nice. Just wish the mirror was level. It slants up.
Early 2006 GM diesels have the LLY Duramax which started in 2004.5 replacing the original LB7 Duramax diesel. Fourth quarter 06 Duramax feature the new LBZ Duramax diesel. The 8th digit on the VIN # should be a 2 for the LLY, the new LBZ will be a 3.The LBZ engine, Duramax and has better pistons, simpler electronic controls, bigger intake etc. The new LBZ Duramax besides more power also has less turbo lag, something I noticed first. This is from a revised variable-geometry turbocharger. Aerodynamic changes to the turbo’s vanes help tailor controlled application of turbo power for seamless and immediate response at full throttle. The turbo, which spins at up to 120,000 rpm, is high-speed-balanced, reducing vibration and resonance. The revised turbo also helps reduce emissions, while maximum boost remains at 20 psi.
New emission law for diesels takes affect in January 2007. Do you think that might drive up the cost of a new diesel pickup? Dodge with the Cummins diesel, has announced some of the details of their 6.7L 07 diesel, but GM and Ford won’t disclose that until closer to the end of the year. So what do you do, buy a new truck now or gamble on the next generation low sulfur burning diesels?
The 06 HD 2500 has new glow-plugs reducing start time by as much as 50 percent, I thought start up time was fast already. The new 6.6L Duramax 6600 turbo diesel V-8 ( LBZ) for the 2006 model year Chevy Silverado HD and GMC Sierra HD has class-leading horsepower – 360 at 3200 rpm and class-leading torque, at 650 lb.-ft. at 1600 rpm. Revised piston design helps lower compression ratio to 16.8:1 from 17.5:1 to reduce engine stress and pressure to burn more fuel for more power. While the lower compression helps reduce NOx emissions. Lower compression also helps reduce noise and vibration, making the 6600 a quieter and smoother engine. Maximum injection pressure increased from 23,000 psi to more than 26,000 psi
The Duramax 6600 also has a new intake air heater to reduce smoke and emissions during cold or light-load driving. The system features a 1000-watt grid heater located in the air intake duct, which is triggered automatically by the engine controller. It heats up the incoming air to speed warm-up of the engine.
Six-Speed Allison Auto
The 2006 GM Allison 6-speed automatic is great, you can put into manual mode and shift if up or down with a toggle switch on the shifter handle. In the dash, is will show you which gear you’re in. The manual shifter was great, total control of the speed of the truck without using brakes. If you plan on taking your horse trailer or RV to the mountains, you’ll love what the new 2006 GM Duramax diesel and the 6 speed auto Allison can do in the mountains. but the new 6-speed automatic transmission is not an unknown reliability. It’s the same as the 5-speed with a undated valve body, larger torque converter and pump. Just added and extra overdrive. The big three diesels should all get you 300,000 miles of life, but the Allison has the history of reliability with big trucks and buses for decades.
The Allison 1000 transmission grows from a five-speed automatic to a first-in-class six-speed automatic for the 2006 Chevrolet Silverado HD and GMC Sierra HD trucks equipped with the Duramax 6600 6.6L V-8 diesel or Vortec 8100 8.1L V-8. Also new for 2006, the Allison 1000 six-speed features a class-first tap-shift range selection function. The gear selection function allows the driver to easily select the desired gears to match driving conditions, like towing a trailer on a steep grade.
The sixth gear – essentially a second overdrive gear – enables a wide, 5.08:1 overall forward gear ratio coverage and allows the vehicle’s engine to operate at lower rpm, particularly during higher-speed driving on highways and freeways. Its 0.61 ratio sixth gear provides a 1550-rpm engine speed at 60 mph, compared with the five-speed transmission’s 1800-rpm engine speed at 60 mph. The engine uses less fuel at lower rpm, enabling increased fuel mileage and range. The ratios of gears 1 through 5 remain the same as the Allison 1000 five-speed, including the 0.71:1 fifth gear.
A tow/haul mode is retained on the Allison 1000 six-speed, but it is complemented by a new range selection feature. It allows the driver to select the desired gears, via a thumb-activated switch on the shifter, providing a feeling of enhanced control in unique driving situations, such as towing on a steep grade. The range selection feature holds the gear pre-selected by the driver and electronic safeguards prevent the transmission from being shifted at high RPM’s causing engine damage or loss of vehicle control. Grade braking and cruise grade braking are only available when the tow/haul mode is selected and the transmission is not in the range selection mode.
Diesel-engine vehicles equipped with the Allison 1000 six-speed feature cruise control grade braking. Working in harmony with the tow/haul mode, the cruise grade braking system will automatically downshift to help maintain the pre-selected cruise speed when driving on downhill grades.
A new low-traction mode also is standard on vehicles equipped with the diesel engine. When the driver selects second gear while stopped and wheel slip occurs, the transmission torque-manages the engine to limit tire slip on slippery road surfaces.
The Allison 1000 also has a unique, GM-patented elevated idle mode, which allows for faster interior warm-up of diesel-equipped vehicles. The system, which is activated through the vehicle’s driver information center, is synchronized with the engine. When elevated idle is active, the transmission increases the load on the engine so that it will generate heat more quickly and warm the interior in less time.
Six Horse Cimarron, Made for Trainers.
Thanks to Transwest Truck Trailer RV www.TrailerWest.com for the 2006 GMC HD 2500 and the 6 horse Cimarron
And thanks to Sonshine Acres www.SonshineAcres.net for the horse models.