AAM 11" Ring Gear, 14 Bolt Differential Cover For GM Trucks

Retail Price: $338.00
Price: $260.00 ea
  • SKU9511AC
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PML AAM 11.5, 11.8 differential cover for GM trucks is designed for:

  • 2001 and newer Sierra/Silverado 2500HD with Duramax diesel
  • 2007 Sierra/Silverado 2500HD Classic with Duramax diesel
  • 2001 to 2006 Sierra/Silverado 3500 with 8.1 V8 gas engine or Duramax diesel
  • 2007 Sierra/Silverado 3500 Classic with 8.1 V8 gas engine or Duramax diesel
  • 2007 and newer Sierra/Silverado 3500HD with Duramax diesel
  • Some 2007 and newer Sierra/Silverado 3500HD with 6.0 V8 gas engine (some have the GM 10.5 inch ring gear, 14 bolt differential)

Always check your vehicle to verify differential and clearance. Configurations vary. Large spare tires may need adjusting toward the rear to increase clearance.

2019, 2020 and newer trucks: These trucks may have the similar AAM 12". Starting around 2020 models, GM changed to a slightly larger differential that looks very similar to this one. See PML AAM 12.0 14 Bolt differential cover for more information.

Some of these trucks can also use PML AAM 11.5 14 Bolt For Ram, which has a different fin pattern, less capacity and requires the brake bracket at the 12 o clock position to be bent.

This cover will fit the AAM 11.5, 11.8 differential on Ram trucks also. However most Ram trucks have the spare tire close to the stock cover and need more clearance than this cover provides. PML makes a cover specifically to fit Ram trucks with the AAM 11.5, 11.8.

Number of Bolts: 14 bolts

Volume: 1 quart over stock

Dimensions: Click here for dimensions.

PML designed this American Axle 11.5 (292mm), 11.8 inch (300mm) ring gear differential cover for the rear end on heavy duty Silverado and Sierra trucks with the Duramax diesel or V8 gas engine.

For the brake bracket, the cover has space at the top and includes longer bolts.


  • Extra capacity
  • Open interior
  • Drain, oil fill, and level check holes to make it easy to follow the 15K oil change interval
  • Magnetic drain plug and new mounting hardware included
  • Finned for heat dissipation and a custom look
  • Heavy duty, sand cast aluminum construction
  • Machined gasket flange for a secure seal
  • Works with stock cover brake bracket
  • Option for temperature sensor machining

Drain, Oil Fill, Level Check and Hardware

The differential cover has oil fill/level check hole and a drain hole with a magnetic plug to facilitate oil changes.

PML includes new mounting bolts, magnetic drain plug with a reusable copper sealing washer and a fill plug with each cover.

Optional Machining for Temperature Sending Unit

This cover has an undrilled boss below the level check hole. Optionally, PML drill and tap this boss with a 1/8 NPT hole for an aftermarket temperature sending unit.

Spare Tire

If you have an oversized spare tire, you may need to move the tire towards the rear. There is tube that holds the spare tire in place and the position can be easily adjusted.

PML Differential Cover Compared to Stock

PML Differential Cover Part Number 9511 compared to stock   PML Differential Cover Part Number 9511, compared to stock, top view
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