GM 8.5", 8.625" Differential Cover 2.875" Depth

Volume: 0.5 qt. over stock

Dimensions: See below, a separate window or tab will open

Applications for a PML GM 10 Bolt Differential Cover

This PML differential cover fits the rear end differential on many GM, GMC, and Chevrolet vehicles. Be aware that for each model and year there may be more than one rear axle possible. See also GM 10 bolt 7.5, GM 14 bolt 9.5, and GM 12 bolt 9.5.

Typical applications for this differential include the following:

½ Ton Trucks, 1979 to Current:

• C10 & K10
• C1500 & K1500
• Silverado 1500
• Sierra 1500

¾ Ton Trucks, 1979 to 1998:

• C20 & K20
• C2500 & K2500

½ Ton Vans, 1979 to Current:

• Vandura
• Express
• Savana
• G1500

¾ Ton Vans, 1979 to Current:

• Vandura
• Express
• Savana
• G2500

Full Size Blazer, 1977 to 1994

GMC Jimmy, 1977 to 1991

Escalade, Tahoe, Yukon,
1992 to Current (check panhard bar clearance)

Avalanche 1500

Suburban 1500, 1982 to Current

Hummer H3

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

GM 8.2 10 Bolt: These rear end covers can also fit on older vehicles with the GM 8.2 differential. For example:

• 1966 Impala
• 1960s Chevelle
• 1966 Pontiac GTO

See our GM 8.2 web page for more information.

4WD Front Applications: See PML Part Number 6077 for GM Front 10 bolt 8 1/2" ring gear differential found on some 4WD Chevy and GMC SUVs and trucks. PML part number 10815 and 6082 are for the rear differentials.

Bolt Information

PML includes mounting bolts with all differential covers. PML provides bolts that are longer than the stock bolts since the flange on PML's cover is much thicker than stock. The bolts with the stock cover will not work.

GM has used four different bolts on these differentials so to complete your order, we need to know which bolts you have. These differentials have used both metric and standard cover bolts. The bolt length has not been consistent either. When ordering one of these covers, you will need to pull one of your stock bolts out (a top bolt is best) and measure the length and determine whether it is metric or standard.

• Bolt length is measured from the underside of the head (where a washer would sit) to the tip. If the bolts are metric, the length will be 21mm or 16mm. If the bolt is standard, the length will be 5/8 inch or 7/8 inch.
• A bolt head with lines or letters on it is typically standard. A bolt with numbers such as 5.8, 9.8, 10.9, or 12.9 is likely to be metric.
• Metric bolts will have 20 threads per inch. Standard ones will have 18 threads per inch. Since the bolts do not have a full inch of threads, try counting the number in a half an inch and multiply by two.

We know this is a hassle, but we do not want to send the wrong bolts or charge everyone a lot of extra money to cover sending all possible bolts with each cover. Watch the video for more information on checking your bolts.

Gasket Information for a PML GM 10 Bolt Differential Cover

PML machines the gasket surface of our differential covers completely flat. The flange surface of the differential housing is also machined flat. A thin bead of RTV silicon sealant makes an excellent seal between two machined surfaces. If you prefer to use a gasket, we have had customers recommend the Fel-Pro RDS 55028-1 gasket.

PML Differential Cover Compared to Stock

Click on image to view larger.

These images show this PML differential cover compared to the stock cover.

This image compares the depth of both PML GM 10 bolt differential covers and the stock cover. Click on image to view larger in a new tab or window. 

PML Differential Cover Features:

• Increased oil capacity for cooler temperatures
• Sand-cast aluminum with raised fins
• 3/16-inch thick wall construction to add strength to differential housing
• 3/8-inch thick gasket flange will not bend when bolts are tightened
• Machined gasket surface for a secure seal using RTV or factory reusable gasket
• Oil changes without removing the cover
• All hardware provided, including magnetic drain plug