Regears a Ford 8.8-inch rear axle to 4.56:1 to get launch and pulling power back after going to 33 to 35 inch tires. Richmond EXCEL F88456 gears only.
When an F-150, Ranger, Explorer or Expedition goes to 33, 34 or 35 inch tires, the factory 3.31, 3.55 or 3.73 rear gears turn it into a truck that lugs off every light and never stays in overdrive. A drag or street Mustang with an 8.8 rear has the opposite goal: get the car into its power band faster. The Richmond Gear EXCEL F88456 is a new 4.56:1 ring and pinion for the Ford 8.8 inch 10-bolt rear axle, and it covers both jobs.
The pinion is splined to the driveshaft yoke and drives the 8.8 inch ring gear bolted to the carrier. This set has 41 teeth on the ring and 9 on the pinion, a 30-spline pinion, 10 ring gear bolts and standard rotation, so the driveshaft turns 4.56 times for every turn of the rear wheels. Going from a 3.55 to a 4.56 is close to a 28 percent jump in torque multiplication, which is roughly what it takes to bring effective gearing back after a large tire increase. Because the 8.8 is so often fitted with a Traction-Lok limited slip, the gear change is also a good time to deal with any clutch chatter, one of the axle's known problems along with pinion bearing whine.
Check the axle tag or the door code for the current ratio, or use our axle ratio and code guide. Make sure the housing is the 8.8 and not the 7.5 or 9.75; the 8.8 has a 10-bolt cover with a slightly irregular shape. A rear whine is not always the gears. Pinion bearings wear out on high-mileage 8.8s and growl in a similar way, as covered in our Ford 8.8 problems and rebuild cost guide. Also think about how the vehicle is used. On stock-size tires a 4.56 raises cruising rpm a lot; for mild tire upgrades the Ford 8.8 3.73 set is the better choice.
This is a standard rotation gear set for Ford 8.8 inch 10-bolt rear axles used under F-150, Ranger, Explorer, Expedition, Mustang, Crown Victoria and many Lincoln and Mercury models. It is not for the 8.8 independent front axle used on F-150 and Expedition 4x4 models, which needs a reverse rotation set like the Ford 8.8 reverse rotation 4.56 set. The 2015-and-later F-150 8.8 rear has its own gear sets, so check that before ordering. Match the 41-9 tooth count, 30-spline pinion and 8.8 inch ring to your old parts, or send us your year and VIN and we will confirm. More 8.8 parts are on our hard parts page.
On a 4x4, regear the front axle to 4.56 at the same time. The 8.8 is a C-clip axle, so remove the pinion shaft lock bolt and shaft, push the axles in and take out the C-clips before the shafts slide out. This box is gears only. Plan on the USA Standard Ford 8.8 master overhaul kit or a matching Yukon master kit for bearings, races, crush sleeve, shims, seal and ring gear bolts. Revolution Gear's setup chart for the 8.8 lists a 0.026 in starting pinion depth, 14-19 in-lb pinion bearing preload, 0.006-0.010 in backlash, and 60 ft-lb on the ring gear bolts and bearing caps. Read the pattern on both sides of the teeth, fill with 75W-140 or 75W-85 gear oil as your vehicle specifies, and add friction modifier for a Traction-Lok. If the clutches chatter, a Dura Grip posi for 31-spline 8.8s can go in during the same job. Break the gears in gently, change the oil after the first few hundred miles, and recalibrate the speedometer for the new ratio and tire size.
| Type | Ring and pinion gear set (gears only) |
| Axle | Ford 8.8 inch, 10-bolt |
| Ratio | 4.56:1 |
| Brand | Richmond Gear EXCEL |
| Part number | F88456 |
| Finish | Machined |
| Does not include | Install kit (bearings, crush sleeve, shims, pinion seal, ring gear bolts) |
| Shipping weight | 20 lb |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is a common pick for F-150, Ranger and Explorer builds on 33 to 35 inch tires, and for street-strip Mustangs that want quicker launches. On stock tires it raises highway rpm noticeably.
No. The F-150 and Expedition 4x4 IFS front 8.8 runs reverse rotation gears. This F88456 is a standard rotation set for the 8.8 rear axle.
No. It is the ring and pinion only. You need a Ford 8.8 master install or overhaul kit with pinion and carrier bearings, races, crush sleeve, shims, pinion seal and ring gear bolts.
Yes. Changing ratio and tire size changes the speed reading and shift points, so reprogram the computer or change the speedometer gear for the new 4.56 ratio and tire diameter.
Use the 75W-140 or 75W-85 gear oil your vehicle calls for, plus friction modifier if it has a Traction-Lok limited slip. Change it after break-in.
