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Thread: G80 RPO Code

  1. #1
    Sr. Apprentice OHChevy03's Avatar
    Join Date
    Oct 2010
    Columbus, Ohio

    Default G80 RPO Code

    I've been looking around on the internet to try to figure out what the G80 RPO Code means and have come across both rear locking differential and limited slip differential. Does anyone know which one it actually is? Any opinions on the two would be appreciated too.
    03 Silverado 5.3L 2WD Ext Cab LS, Summit White
    Cooper Discoverer S/T 265/75-16s
    Back Country Step Bars
    Daystar Leveling Kit

  2. #2


    the g80 is a eaton automatic locker. it is sometimes called a limited slip and works the same way but when it feels wheel spin in excess of I think 25 rpms (something like that) it fully locks (equal power to both wheels). whereas a limited slip will transfer power but will still send more power to the wheel with less traction. It then will unlock when vehicle speed is greater than 25 mph, or you stop, no wheelspin etc. It uses a bunch of cluth plates to do this.
    2004 Silverado 2500 Crew Cab 4x4, AMSOIL EA air filter, Granatelli MAF sensor, Throttle body spacer, Magnaflow exhaust (true dual to 2 in 1 out muffler), 6" ProComp lift (add a leaf and 5" superlift rear block), Bilstein shocks, 35's (Cooper Disoverer ST) and 4.10 gears, Rhino Liner, EGRUSA fender Flares and widow visors, extended stainless steel brake lines, firestone airbags w/onboard air compressor, Pioneer Avic X940BT navigation, Accel backup camera.
    1960 Land Rover Series II 88
    2001 Pontiac Sunfire
    2013 Toyota Avalon Limited (Wife's Car)
    NRA Life Member

  3. #3


    The G80 is....A Locker...Although some Limited-Slip Action Occurs,

    The optional locking differential (RPO G80) enhances the traction capability of the rear axle by combining the characteristics of a limited-slip differential and the ability of the axle shafts to "lock" together when uneven traction surfaces exist. The differential accomplishes this in 2 ways. First by having a series of clutch plates at each side of the differential case to limit the amount of slippage between each wheel. Second, by using a mechanical locking mechanism to stop the rotation of the right differential side gear, in order to transfer the rotating torque of the wheel without traction to the wheel with traction. Each of these functions occur under different conditions.

    Limited-Slip Function:
    Under normal conditions, when the differential is not locked, a small amount of limited-slip action occurs. The gear separating force developed in the right-hand clutch pack is primarily responsible for this.

    The operation of how the limited-slip function of the unit works can be explained when the vehicle makes a right-hand turn. Since the left wheel travels farther than the right wheel, it must rotate faster than the ring gear and differential case assembly. This results in the left axle and left side gear rotating faster than the differential case. The faster rotation of the left-side gear causes the pinion gears to rotate on the pinion shaft. This causes the right-side gear to rotate slower than the differential case.

    Although the side gear spreading force produced by the pinion gears compresses the clutch packs, primarily the right side, the friction between the tires and the road surface is sufficient to overcome the friction of the clutch packs. This prevents the side gears from being held to the differential case.


    5.3 l 3.73 l G80

  4. #4
    Sr. Apprentice OHChevy03's Avatar
    Join Date
    Oct 2010
    Columbus, Ohio


    Would the year of your truck make the G80 RPO mean something else? I have also heard that it could but didn't get a for sure answer when looking on other forums. I am pretty sure mine is the G80 Eaton automatic locker.

  5. #5


    I doubt that it would mean anything else, at least on any truck that is half way recent.

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