How do I identify my Chevy rear differential?

The rear cover’s shape and the number of bolts are identifying features for GM rear differentials. The round 10-bolt cover with a bulge for the ring gear identifies this axle assembly as an 8.5-inch 10-bolt. The two lugs on the lower case at the 5 and 7 o’clock positions are also identifying features.

How do I know what rear differential I have?

Visual Differential Identification Without an ID tag, differentials are identified by the number of cover bolts, the distinctive shape of the cover, the number of ring gear bolts, and ring gear diameter. They can also be identified by whether the center section is an integral or dropout design.

What do rear differential numbers mean?

The term refers to the gears in the truck’s differential, which is a mechanical device that links the rear axle to the driveshaft and then the engine. Technically, the number should be expressed as a ratio, such as 3.55:1, meaning the drive shaft turns 3.55 times for each turn of a wheel.

How do you tell if I have a 8.2 or 8.5 rear end?

Another way to tell the difference between an 8.2 and an 8.5 rearend is to pull the cover and look at the bolt holding the spider gear crosspin. If it takes a 1/2-inch wrench to remove it, it’s an 8.2. If it takes a 5/16-inch wrench to remove it, it’s an 8.5.

What rear end is in a 72 Nova?

Premium Member. Yeah, 1972 was the first year for the 8.5, 10 bolt rear end in the Nova.

What size is my rear differential?

Measure the ring gear diameter. The ring gear is the largest gear inside the differential housing and normally faces the driver’s-side rear wheel. Using a tape measure or machinist’s ruler, measure the ring gear diameter. This identifies the differential — a Ford 9-inch or GM 7.5-inch — for example.

How do I know what gear ratio My rear end is?

Count the number of teeth on the pinion gear and count the number of teeth on the ring gear. Divide the ring gear teeth number by the number of teeth on the pinion. The result is your gear ratio.

What kind of differential does a 12 bolt Chevy have?

As you can see, the Chevy 12-bolt differential is one stout axle, and it was the rear axle of choice for GM muscle cars and many GM competition cars. Big-block Chevelles, Camaros, and other GM high-performance vehicles were fitted with the 12-bolt limited-slip axle to maximize torque transfer and traction. (Photo Courtesy Moser Engineering)

What are the rear end codes for a Chevy?

Chevrolet Rear End Codes G3GM 1973 to 1977 A-bodys. Chevelles, Monte Carlos, El Caminos, Laguna, 442, Cutlass, Malibu, GTO, LeMans, Century, Regal, Grand Am, Grand Prix, Sprint, Gran Sport, Can Am, Hurst-olds, and other 73-77 A-bodies Search Query

What is the GM RPO code for rear axle?

(Accurate identification using the GM RPO code assumes that the rear end has not been previously modified) The prefix is usually F, G or H when referring to Axle Identification. The list below is a partial list of typical GM RPO Codes, specifically the codes pertaining to Axle Identification, Differential Type and Gear Ratio.

What are the RPO codes for a Chevy?

RPO Codes: G80 Axle Positraction, Limited Slip G81 Positraction Rear Axle G82 Axle Rear 4.56 G84 Axle Rear 4.10 G86 Axle , Rear, Limited Slip G87 Ring Gear, 8.50 Inch