AAM for 2020 & Newer GM/Allison Trucks
Part Number 11173

Volume: about 0.5 quarts over 2020 stock GM truck cover

Dimensions: Click here for dimensions.

Number of Bolts: 14

Description: 2020 and newer GMC/Chevy heavy duty trucks have a new version of the American Axle Manufacturing (AAM) 14 bolt differential. The ring gear may be 12 inches or 11.8 or 11.5.

Pictures of PML new AAM 14 Bolt for 2020 and newer Silverado and Sierra 2500 and 3500 trucks:

2020+ 14 bolt PML cover for GM HD trucks   PML rear differential cover, view of level check hole   2020+ 14 bolt PML cover for GM HD trucks, black powder coat finish
Part shown in natural as cast finish and in black powder coat finish. Click on image to view larger.

This new American Axle differential has a cover very similar in shape and bolt hole pattern to the cover on 2001 to 2019 trucks. But the covers and gaskets are not the same and not interchangeable.

Benefits:

• Drain and magnetic drain plug included
• Heavy duty, sand cast aluminum
• Finned for heat dissipation
• Works with brake line bracket, no modification needed
• About 3/8 inches deeper than stock for clearance to sway or pan hard bars
• Shape similar to stock cover
• Extra capacity

GM vehicles that probably have these new differentials:

• 2020 GMC Sierra 2500 and 3500 trucks
• 2020 Chevrolet Silverado 2500 and 3500 trucks

Configurations vary. Always check your vehicle to verify differential and clearance.

The GM gasket part number for this differential is 68454491AA.

This includes trucks with the Allison transmission.

For 2019 and older trucks with the AAM 11.5, 11.8 differential, see PML part number 9511.

Installations

• 2022 Sierra 2500HD
• 2020 Sierra 2500HD Diesel

2022 Sierra 2500 HD

Jon installed this PML rear differential cover on his 2022 GMC Sierra 2500HD with a gas engine.

2022 Sierra 2500HD   OEM rear differential cover   PML differential cover installed   PML differential cover installed
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2020 Sierra 2500HD Diesel

Jody installed this PML rear differential cover on his 2020 GMC Sierra 2500 Denali with the Duramax engine. He reported that the installation went well.

2020 Sierra 2500 Denali Duramax   PML cover installed   PML cover installed, works with stock bracket
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PML Cover Compared to GM Stock Cover

PML cover next to GM stock cover, outside and inside.

 
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Stock Covers and Gaskets

2020 GMC Sierra 2500 Gas Engine Stock Rear Differential Cover:

 Click on image to view larger.

2020 and newer GM HD truck stock cover (outside, inside, part number):

   
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For comparison, here is the 2001 to 2019 stock differential cover:

 Click on image to view larger.

2019/2020 and Newer Gasket (GM gasket part number 68454491AA) and Gasket for Prior AAM 11.5, 11.8 Differentials:

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