Hummer H1 Differential Cover – Heavy Duty Aluminum Upgrade

Enhance the durability and protection of your drivetrain with this Hummer H1 Differential Cover, designed to handle the most demanding off-road and extreme-duty conditions. Built for strength and reliability, this upgraded cover helps protect your differential while maintaining optimal performance.

Constructed from high-quality aluminum, this differential cover provides superior durability compared to factory stamped covers. The heavy-duty design helps shield internal components from impact and debris while improving heat dissipation to keep your differential running at optimal temperatures.

Engineered as a direct-fit replacement for Hummer H1 differential applications, this cover delivers dependable fitment, secure sealing, and long-lasting performance in the toughest environments.

✅ Key Features:

• Fits Hummer H1 differential applications
• Heavy-duty aluminum construction for maximum strength
• Improves heat dissipation and cooling
• Provides added protection for internal components
• Ideal for off-road, military-style, and extreme-duty use
• Direct fit for easy installation and leak-free sealing

Upgrade your H1 with confidence and ensure maximum durability and protection in extreme conditions.

Volume: approximately 0.5 quarts over stock

Dimensions: approximately 11.7 tall x 11.8 wide x 3.8 deep

Number of Bolts: 12

PML designed this differential cover for Hummer H1 and HMMWV Humvee. It fits both the front and rear axles and works with standard undercarriage protection and brake calipers.

Benefits:

• Extra capacity
• Drain and magnetic drain plug for easier servicing
• Fins and sand cast aluminum construction to dissipate heat from the fluid
• Bolt on replacement for stock covers
• Wide gasket flange for a secure seal to the housing
• Thick walls to add strength to the differential housing
• Bosses that can optionally be machined for a temperature sending unit
• Includes new mounting bolts, fill plug and magnetic drain plug

Applications:

This differential cover has been installed on many Hummer H1 as well as M998 Humvee (HMMWV) vehicles. The front and rear differential are the same and this cover fits both.

No modifications to standard undercarriage protection needed. It is designed to slide between the brake calipers.

Always check your vehicle to verify configuration and clearance before ordering.

Aftermarket Brake Calipers

On Hummer H1 the front and rear differentials are the same. This cover fits both. It is designed to slide between the brake calipers.

On an H1 with an aftermarket brake kit with larger calipers, one of the calipers had to be loosened to remove the stock covers and install this PML differential cover. After installation, the caliper was retighted. No modifications were needed. We do not know which brake kit so there may be variations.

This installation is on a H1 with stock brake calipers.

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Included With Cover

PML Hummer differential covers ship with new mounting bolts, washers, fill plug, and a magnetic drain plug.

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Inside of Cover, Drain Hole, and Fill/Level Check Hole

Drain: Drain on bottom of cover for easy fluid changes. Magnetic drain plug included.

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Inside: The PML cover features an open interior like the stock cover. The PML cover is round, following the same general shape as the stock cover.

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Fill Hole: The fill/level check hole on the PML cover is at the same height as on the stock cover for an accurate fluid level. This hole is on the front of the cover for easy access, as seen in the above pictures. PML provides a plug for the hole.

PML Differential Cover Compared to Stock

   
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