9.5"-12 Bolt Heavy-Duty Cast Aluminum Rear Differential Cover (Black)

Features:

• A356.0-T6 heat-treated cast aluminum
• Precision cast in permanent steel molds
• Adds 0.57 quart of fluid capacity
• Half-inch external cooling fins
• Internal windage scrapers reduce churning and heat
• Cross-bracing structure improves impact resistance
• Cast-in gussets add flange support
• 304 stainless service plugs with neodymium magnets
• Fill plug set to factory fluid level
• Black cast aluminum finish
• Made for 3.0L Duramax Silverado and Sierra 1500
• For 9.5"-12 bolt axles, build code SU8

Fight The Heat That Quietly Wears Out Your Diesel 1500's Rear Differential

Heat is the silent enemy of a rear differential, and most owners never think about it until something starts to whine. According to PPE, excessive heat breaks down the protective qualities of the differential fluid, which leads to faster wear on the gears and bearings. In a limited slip differential, constant high temperatures can also wear down the clutch packs and friction modifiers, which hurts traction and efficiency. A 3.0L Duramax Silverado or Sierra 1500 is a half ton that is often asked to tow and haul like something bigger, so the rear axle is working hard. PPE built this cover to help manage that heat with 0.57 quart of extra fluid capacity, half inch external fins, and internal scrapers that keep the fluid from churning more than it needs to. The service plugs hold powerful magnets that capture ferrous particles before they can circulate through the gears. You also get a proper drain plug and a fill plug set at the factory fluid level, so the next fluid change is far easier than dealing with a stock cover. For a diesel 1500 that tows and hauls, it is a strong upgrade for a part that takes more abuse than it gets credit for.

Windage Scrapers, Cross Bracing, And Magnetic Plugs Built Into A Cast A356 Cover

PPE casts this cover from A356.0-T6 aluminum alloy, which it describes as a high strength, thermally conductive material. The cover is made in permanent steel molds, which PPE says gives a smooth, consistent finish and high dimensional accuracy. Half inch external fins improve heat dissipation, lower the differential fluid temperature, and add impact resistance. Precisely placed internal windage scrapers keep the fluid from churning excessively, which PPE says reduces heat generation, fluid aeration, and power loss. Together, the external fins and the internal scrapers form 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 fluid level. PPE lists the GM OE reference as 85586188, which replaces 23243722 and 84553988. This cover is for 2020-2026 Chevrolet Silverado 1500 and GMC Sierra 1500 trucks with the 3.0L turbo diesel Duramax and the AAM 9.5 inch, 12 bolt rear axle with build code SU8 only, and it is not compatible with the SU7 axle.

Fitment: 2020, 2021, 2022, 2023, 2024, 2025, 2026 GM Silverado/Sierra 1500 3.0L I6 Turbo Diesel Duramax, AAM 9.5"-12 bolt rear axle, build code SU8 only

Notes:

• For 3.0L Duramax Silverado and Sierra 1500 trucks with the AAM 9.5"-12 bolt rear axle and build code SU8 only, confirm your axle build code before ordering
• Not compatible with AAM 9.5" rear axles with build code SU7, PPE directs SU7 trucks to part 138051200
• Adds 0.57 quart of fluid capacity over the stock cover
• GM OE reference 85586188, which replaces 23243722 and 84553988
• 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