TransGo A1-LU-BST Boost Valve | 2001-2004 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LB7

Features:

• Controls fluid flow to converter clutch
• Reduces line pressure during clutch apply
• Keeps main line pressure up to 190 PSI
• Improves transmission shift consistency
• Designed for Allison LB7 transmissions
• Compatible with 2001-2004 6.6L Duramax
• Helps prevent converter clutch slippage
• Enhances transmission reliability and longevity
• Precise pressure cut-back control
• Reduces stress on transmission components
• Ideal for stock and tuned trucks
• Easy upgrade for better drivability

Get Smoother Shifts And A Happier Transmission

If you’ve ever felt your truck hesitate or slam into gear when the converter clutch kicks in, you’re not alone, and the TransGo A1-LU-BST Boost Valve might be exactly what you need. Built specifically for 2001-2004 GM 2500HD and 3500HD trucks running the 6.6L Duramax with the Allison LB7 transmission, this small upgrade packs a serious punch in drivability. It controls fluid flow to the converter clutch and helps lower harsh line pressure from 255 PSI to a more manageable level, creating smoother and more consistent shifts. That means less wear on your transmission and a better overall driving feel, especially under load or while towing. Whether your truck is bone stock or mildly tuned, this valve can make daily driving and heavy hauling a whole lot more enjoyable. The install is straightforward, and once it’s in, you’ll notice the difference right away. It’s one of those upgrades that doesn’t just fix a problem, it makes the whole truck feel more dialed in.

Keep Pressure Under Control Where It Matters Most

The TransGo A1-LU-BST Boost Valve is engineered to improve pressure control in the Allison LB7 automatic transmission, specifically during converter clutch engagement. In stock form, the transmission’s line pressure can spike to around 255 PSI when the clutch applies, which creates unnecessary stress on internal components. This valve brings that number down to a more efficient 155 PSI, helping to reduce strain and extend the life of the transmission. What makes this component especially valuable is its ability to maintain mainline pressure up to 190 PSI, even after cut-back, providing a perfect balance of performance and protection. It offers more precise modulation of converter clutch behavior, allowing for smoother engagement without sacrificing torque handling. Designed specifically for use with 2001-2004 GM Silverado and Sierra HD models, this valve is ideal for any truck owner looking to fine-tune how their Allison transmission behaves under pressure. It’s a technical solution to a common drivability complaint, and one that can make a measurable difference.

Fits: 2001, 2002, 2003, 2004 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LB7

Notes:

• Designed specifically for Allison LB7 transmissions
• Fits 2001-2004 GM 2500HD and 3500HD 6.6L Duramax
• Controls fluid flow to the converter clutch
• Lowers main line pressure during clutch apply
• Reduces pressure from 255 PSI to 155 PSI
• Allows mainline pressure to remain up to 190 PSI
• Helps prevent converter clutch-related transmission issues
• Does not require tuning or electronic changes
• Ideal for improved drivability and shift quality
• Installation requires access to internal transmission components