1000/M74 2007 Chevy/GMC Silverado/Sierra HD Classic 6.6L RWD – Remanufactured 6-Speed Automatic Trans

Description

Tuned for commercial rear-wheel diesel hauling, GMC Sierra 2007 Remanufactured Transmission units handle 6.6L Duramax output in 2WD Classic HD chassis. This remanufactured 6-Speed Allison 1000 unit manages 460 continuous horsepower, 650 lb-ft maximum torque, and an engine ceiling of 4000 RPM while maintaining internal hydraulic pressure of 230 PSI.

Cast A380 aluminum casing encases 3 planetary gear modules formed from carburized 8620 steel. High-energy graphite friction plates with radial cooling grooves suppress excessive heat across all forward and reverse clutch packs. Re-machined Gen-4 valve body bores receive hard-anodized sleeves to prevent pressure loss and shift flare. Sump fluid capacity requires 14.5 quarts of approved automatic fluid through 1/2-inch cooler ports. Total dry weight stands at 325 lbs, coupled with a balanced lockup torque converter.

Key Features of GMC Sierra

Fleet supervisors choose to buy GMC Sierra 2007 remanufactured transmission units to eliminate shift flare across commercial diesel vehicle fleets. Factory reconditioning replaces all wear items to maintain exact hydraulic line pressure and continuous torque transfer across all 6 forward gear ranges.

• 8620 case-hardened planetary gears resist gear tooth pitting under severe 650 lb-ft diesel torque.
• Radial-grooved friction plates circulate fluid to stop clutch pack burn during heavy vehicle acceleration.
• 14.5-quart fluid capacity stabilizes hydraulic circuit temperatures during continuous highway hauling.
• 2007 Sierra replacement valve body prevents internal cross-leaks across double overdrive gear steps.
• Sierra 2007 torque converter package locks fast under load to eliminate slip during highway cruising.
• 6-Speed gearing provides dual overdrive ratios spanning 3.10:1 in 1st gear down to 0.61:1 in 6th gear.
• 230 PSI mainline hydraulic pressure locks clutch plates fast to eliminate mid-gear slippage.

Six-Speed Diesel Propulsion Thermal Management

High-flow internal fluid pumps maintain hydraulic mainline pressure between 190 and 230 PSI, keeping sump temperatures between 165°F to 195°F. Input torque absorption handles 650 lb-ft at 1600 RPM without clutch pack slippage. Gear ratios progress from 3.10:1 in 1st gear to a tall 0.61:1 in 6th gear overdrive, keeping Duramax diesel engines in their optimal fuel efficiency zone at lower highway engine revolutions. An external cooler loop sheds excessive heat through 1/2-inch fittings, protecting rotating planetary carriers and needle bearings.

Rear Driveline Slip Yoke Alignment

A 34-spline rear output shaft links straight with 2-Wheel Drive slip yokes. Output shaft runout is verified under 0.0018 inches on dial indicators, stopping cab vibrations at highway speeds. Die-cast aluminum casing mounts bolt flush to GM crossmember brackets, preserving factory universal joint working angles under heavy chassis payloads.

Automated Dyno Validation Maintenance Procedures

Technicians test every unit on an automated spin dynamometer under heavy simulated road load conditions to confirm 6-Speed shift solenoid response, hydraulic line pressure curves, and torque converter lockup holding force. This transmission is not engineered for truck pulls, drag racing, or vehicles running with clogged auxiliary transmission cooler lines.

• Inspect transmission fluid dipstick level and color every 14 operating days.
• Replace synthetic transmission fluid and the spin-on filter every 25,000 miles.
• Flush transmission fluid cooler circuits every 12 months to prevent debris blockage.

Nationwide Commercial Fleet Warranty Terms

A 3-Year unlimited mileage warranty protects commercial fleet owners against premature mechanical defects nationwide. Each heavy wooden transport crate includes the complete remanufactured automatic transmission, a balanced lockup torque converter, a new spin-on external fluid filter, complete installation instructions, cooler flushing guidelines, and fluid specification documentation tags.