AAM 9.5"/9.76"-12-Bolt Heavy Duty Cast Aluminum Rear Differential Cover (Black Finish)

Features:

• A356.0-T6 heat-treated cast aluminum
• Black cast aluminum finish
• Adds 0.6 quart of fluid capacity
• Half-inch external cooling fins
• Internal windage scrapers reduce churning and heat
• Cross-bracing structure improves rigidity
• Cast-in gussets add flange support
• 304 stainless plugs, neodymium magnets, Viton O-rings
• Fill plug set at factory fluid level
• Fits AAM 9.5" and 9.76" 12 bolt axles
• For build code SU7 axles only
• Made for 3.0L Duramax Silverado and Sierra 1500

A Blacked Out Differential Cover That Does Real Work Behind The Looks

If you have already given your Duramax 1500 a blacked out look, the rear axle housing can be the one part that still looks stock. This PPE cover fixes that with a black finish, and it does a good deal more than add style. PPE says excessive heat breaks down the protective qualities of differential fluid, which speeds up wear on the gears and bearings. To help with that, the cover adds 0.6 quart of fluid capacity, which PPE says gives the system higher thermal capacity. Half inch fins along the outside help move heat out of the housing, and PPE says they lower the differential fluid temperature. On the inside, scrapers keep the fluid from churning more than it needs to, which cuts down on heat, aeration, and power loss. The magnets in the drain and fill plugs capture ferrous particles, so metal wear stays out of the gears. For a diesel half ton that tows and hauls, you get a cleaner look and a better-protected axle from a single part.

Gusseted Flange Support And Stainless Service Plugs Packed Into A Black Cast Cover

The PPE 138051220 is a black finish, heavy duty cast aluminum rear differential cover for AAM 9.5 inch and 9.76 inch, 12 bolt rear axles on Silverado and Sierra 1500 trucks with the 3.0L turbo diesel Duramax. PPE casts it from A356.0-T6 heat treated aluminum in permanent steel molds, which it says gives a smooth, consistent finish and high dimensional accuracy. The cover adds 0.6 quart of fluid capacity, and half inch external fins improve heat dissipation, lower the differential fluid temperature, and add impact resistance. Precisely placed internal windage scrapers prevent excessive churning, which PPE says reduces heat generation, fluid aeration, and power loss. The scrapers and the external fins work together as a cross bracing structure, and cast in gussets add support at the differential housing flange. The service plugs are 304 stainless steel with high temperature neodymium magnets and Viton O rings, and the fill plug sits at the factory level. PPE lists the GM OE references as 22951487, 25824253, and 84446288. This cover is for build code SU7 only, and trucks with the SU8 axle need PPE's 9.5 inch, 12 bolt cover instead.

Fitment: 2020, 2021, 2022, 2023, 2024, 2025, 2026 GM Silverado/Sierra 1500 3.0L I6 Turbo Diesel Duramax, AAM 9.5"/9.76"-12 bolt rear axle, build code SU7 only

Notes:

• For 3.0L Duramax Silverado and Sierra 1500 trucks with the AAM 9.5"/9.76"-12 bolt rear axle and build code SU7 only, confirm your axle build code before ordering
• Not compatible with GM 9.5" rear axles with build code SU8, PPE's 9.5"-12 bolt covers for SU8 trucks are 138051400 (raw), 138051410 (brushed), and 138051420 (black)
• Black finish, raw (138051200) and brushed (138051210) versions are sold under separate part numbers
• Adds 0.6 quart of fluid capacity over the stock cover
• GM OE references 22951487, 25824253, and 84446288
• Fill plug is positioned at the factory fluid level, both plugs are 304 stainless steel with neodymium magnets and Viton O-rings
• Heat, wear, and fluid temperature benefits are manufacturer statements, results will vary
  

Install Instructions