Revolution Gear & Axle GM 14-Bolt 11.5in 4.56 Ratio Ring & Pinion Set
Revolution Gear & Axle GM11.5-456 is a 4.56 ring and pinion for the GM/AAM 11.5 inch rear axle, the 14-bolt-cover full-floater under many heavy-duty Chevrolet Silverado and GMC Sierra 2500HD and 3500 trucks and 2003-2013 Ram 2500 and 3500 pickups. It is the deeper of the two ratios Revolution offers for this axle, and buyers usually reach for it after a lift and 35 to 37 inch tires, a heavy camper or flatbed, or a combination of all three has left a truck that used to pull hard feeling flat and hot under load.
The pinion gear on the end of the driveshaft drives the 11.5 inch ring gear, which turns the carrier and the full-floating axle shafts. With 4.56 gears, the driveshaft spins 4.56 times per wheel revolution. That is about 11 percent more engine speed than a 4.10 set and about 22 percent more than 3.73 at the same road speed, which is exactly what large, heavy tires take away. With the right ratio the transmission holds its top gears, the converter locks up sooner and fluid temperature stays down while towing. Revolution lists this gear set with a 30-spline pinion, standard rotation, 12 ring gear bolts with 9/16 inch threads, no carrier break and 8620 steel construction, so the factory carrier in an 11.5 accepts it.
Rule out bearings before blaming the gears: a drone that stays the same on and off throttle is usually a pinion or carrier bearing, while a whine that changes between drive and coast points at the gear mesh. Our drive vs coast whine guide explains the road test, and the AAM 11.5 problems guide covers the usual wear points. For the ratio, multiply the gear you have by the old tire height and divide by the new one. A truck on 3.73 gears that goes from 32 inch to 37 inch tires effectively drops to about 3.23 (3.73 x 32 / 37); getting back to the stock feel takes about 4.31, and towing or mountain driving makes 4.56 the safer pick. On a 4x4, the front axle must be regeared to the same 4.56 ratio. Ram owners can do both ends at once with the 2003-10 Ram 11.5 and 9.25 4.56 gear package.
This set fits the GM/AAM 11.5 inch rear with a 14-bolt cover and a 30-spline pinion. It does not fit the older GM 14-bolt 10.5 inch axle, which looks similar from the outside; our 14-bolt 10.5 vs AAM 11.5 guide shows how to tell them apart. Revolution sells separate gear sets for the 2019-and-newer GM 11.5, for the 2014-and-later coil-spring Ram 2500, and a face-hobbed set coded DC, and 2014-up Ram 3500 duallys use an 11.8 inch axle, so those trucks need a different part. Read the axle tag, or send us the year and VIN and we will confirm before you order. If you are keeping tires closer to stock, the 4.10 version of this 11.5 set keeps highway rpm lower. More axle parts are in our hard parts category.
Install new bearings with new gears. The pinion bearings changed in 2011, so 2010-and-older axles take the 2001-2010 AAM 11.5 overhaul kit or the 03-10 GM/Dodge 11.5 master install kit, and 2011-up axles take the 2011-up 11.5 master overhaul kit. Revolution's setup chart for the GM 11.5 gives a 0.055 inch starting pinion shim, 20-30 in-lb pinion bearing preload with new bearings, 0.006-0.010 inch backlash, 175 ft-lb on the ring gear bolts and 200 ft-lb on the bearing caps. Confirm the pattern with marking compound before the final torque. Revolution's break-in guidance is conventional GL-5 gear oil, no towing for the first 500 miles and a fluid change at 500 miles; after that, refill with the viscosity in your owner's manual. Our break-in procedure has the full routine. Recalibrate the speedometer and transmission for the new ratio and tire size.
| Brand | Revolution Gear & Axle |
| Part number | GM11.5-456 |
| Fits | Revolution Gear & Axle GM 14-Bolt 11.5in 4.56 Ratio Ring & Pinion Set |
| Type | Ring & Pinions |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is a common choice for 35 to 37 inch tires, especially on trucks that tow or carry heavy loads. Use the tire math: current ratio times old tire height divided by new tire height, then pick the ratio at or just above the result.
No. Revolution lists no carrier break for the GM 11.5 gear set, so the 4.10 and 4.56 ring gears bolt to the same carrier.
No. The 2019-up GM 11.5 uses its own gear set. Send us your year and VIN if you are not sure which axle your truck has.
It fits the AAM 11.5 used on 2003-2013 Ram 2500 and 3500 trucks. The 2014-up Ram 2500 uses a different 11.5 gear set, and 2014-up Ram 3500 duallys use the 11.8 inch axle.
Yes. The front axle must run the same 4.56 ratio as the rear, or the driveline binds in four-wheel drive. Ram owners can buy a matched front and rear gear package.
Revolution recommends conventional GL-5 gear oil, no towing for the first 500 miles and a gear oil change at 500 miles.
