Transmission Rear Housing Support

Features:

• Prevents cracking of 4x4 transmission housing
• Protects against driveline vibration damage
• Fits 2011-2019 Allison 4x4 transmissions
• Helps avoid costly housing replacements
• Made from strong 7/8 .120 wall DOM tubing
• Fabricated in-house by Merchant Automotive
• Installs using existing factory bolt locations
• Quick and easy driveway-friendly installation
• Ideal for trucks with worn u-joints or driveshafts
• Built to withstand off-road and towing stress
• Reinforces rear housing for long-term durability

Protect Your Allison Before Damage Starts To Show

You don’t have to be romping through deep mud or hauling max payloads to run into trouble with your 4x4 transmission housing. Even a worn u-joint or slightly out-of-balance driveshaft can create vibrations that crack the rear housing on your Allison-equipped Duramax. That kind of damage doesn’t just sideline your truck, it can cost over a thousand dollars to fix. The Merchant Automotive Transmission Rear Housing Support is a simple, effective way to avoid all that. This brace adds critical reinforcement to the back of your transmission, helping it stand up to real-world stress. It’s built from heavy-duty DOM steel tubing and bolts right into place using your factory hardware. Whether you're off-roading, towing, or just want peace of mind for your daily driver, this upgrade delivers solid protection where it matters most. It's the kind of part you hope you'll never need, but you’ll be glad you installed it.

Durable In House Fabrication Built For Real Work

The Merchant 10357 Transmission Rear Housing Support is purpose-built for 2011-2019 GM 2500HD and 3500HD 4x4 trucks running the Allison transmission. This part addresses a known failure point where driveline vibrations, often from worn u-joints or damaged driveshafts, can lead to cracks in the rear transmission housing. To prevent this, Merchant fabricates each support in-house using 7/8 inch .120 wall DOM mild steel tubing, chosen for its strength and rigidity. The design spreads stress across a more stable mounting surface, reducing the likelihood of fatigue-related failure. Installation is straightforward and uses existing factory bolt locations, so no custom tools or fabrication is required. It can be done right in your garage or driveway in less than an hour. Whether your truck is stock or modified, this brace is a smart way to add long-term durability without overcomplicating your build.

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 4x4 trucks with Allison transmissions
• Cracked rear transmission housings are a known issue on these trucks
• Driveline vibrations from bad u-joints or bent driveshafts can cause housing failure
• Replacing a cracked housing can cost over $1000
• This support helps prevent damage before it starts
• Made from 7/8 inch .120 wall DOM mild steel tubing
• Fabricated in-house by Merchant Automotive for quality control
• Installs using existing factory bolt locations
• No transmission or driveshaft removal required for install
• Can be installed easily in a garage or driveway