Allison Valve Body

Features:

• Fits 2011–2019 GM 6.6L Duramax with Allison 1000
• Rated for over 1000 horsepower applications
• Includes TransGo Jr. shift kit upgrade
• Improves shift accuracy and transmission reliability
• Includes new A and B trim solenoids
• OEM switch manifold installed for added durability
• Dyno-tested before shipping for verified performance
• Fixes common Allison 1000 shift error codes
• Drop-in replacement for stock valve body
• Handles higher line pressure than OEM unit
• Relearn procedure required after installation
• Core charge required unless pre-exchanged

Give Your Allison The Upgrade It Deserves

If your Duramax is making serious power, don’t let a weak valve body hold you back. The SunCoast A1-VB-LML Allison Valve Body is built to handle the demands of high-performance driving, whether you’re towing heavy, running big injectors, or dialing in aggressive tuning. Factory valve bodies often become a weak link once power levels rise, leading to harsh shifts, slipping gears, or even failure. This drop-in replacement is packed with upgrades that improve reliability and shift quality, while eliminating common transmission issues that plague the Allison 1000. It features a TransGo Jr. shift kit, brand new trim solenoids, and a fresh pressure switch manifold to support stronger line pressure and better overall control. The result is smoother, more confident shifting under load and a drivetrain you can trust when the boost is cranked up. If you want to keep putting power to the ground without second-guessing your trans, this is the upgrade that delivers.

Built To Fix Weak Links And Hold More Power

The SunCoast Allison Valve Body is engineered specifically for 2011–2019 Duramax trucks running the Allison 1000 transmission, offering a major step up in both strength and performance. This unit replaces the factory valve body with a fully built version that includes a TransGo Jr. shift kit, which utilizes hardened steel trim valves, upgraded springs, and new balls to improve shift timing and friction plate durability. New A and B trim solenoids are installed and tested in-house for consistent performance, while a new OEM switch manifold helps prevent internal failure and ensures smoother operation under load. The entire assembly is dyno-tested before it leaves the shop, so you know it's ready to handle real-world abuse. This valve body is rated for over 1000 horsepower and is ideal for trucks running larger turbos, heavy tuning, or towing under demanding conditions. It does require a transmission relearn after installation, and a pump upgrade is recommended for those chasing max line pressure gains. A refundable core charge also applies, unless you send your factory unit in ahead of time.

Fitment: 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Notes:

• Fits 2011–2019 GM 2500HD/3500HD with Allison 1000
• Rated for over 1000 horsepower applications
• Drop-in replacement for factory valve body
• Includes TransGo Jr. shift kit and new solenoids
• Fixes common Allison shift error codes and failures
• Requires transmission relearn after installation
• Core charge required unless core is sent in advance
• Includes new OEM pressure switch manifold
• Ideal for tuned trucks with big turbos or injectors
• Pump upgrade recommended for max line pressure gains
• Each valve body is dyno-tested before shipping