Revolution Gear & Axle Ford 8.8in Rear Axle 3.55 Ratio Ring & Pinion Set
A Ford 8.8 that whines at 50 to 60 mph, a Mustang or Explorer that came with highway-friendly 2.73 or 3.08 gears and now feels lazy, or a Ranger that needs a taller ratio than the 4.10 it was built with all end up at the same question: which ratio do I put in? The Revolution Gear and Axle F8.8-355 is a new 3.55 ring and pinion for the standard-rotation Ford 8.8 inch rear axle. It sits in the middle of the 8.8 ratio range, deep enough to wake up a car or SUV on stock or slightly larger tires, but still tall enough that the engine is not buzzing on the interstate.
The driveshaft spins the pinion, the pinion turns the ring gear, and the ring gear turns the carrier and both axle shafts. A 3.55 ratio means the driveshaft turns 3.55 times for each turn of the tires. Revolution builds this set from 8620 steel with a 30-spline pinion, an 8.8 inch ring gear and ten 7/16 inch ring gear bolts. The 8.8 has no carrier break, so the same carrier accepts every ratio from 3.55 through 5.13 in this gear line. That makes the 3.55 a straight swap for most 8.8 owners without buying a different carrier.
Be careful separating gear noise from bearing noise. Ford 8.8 pinion bearing wear and axle bearing noise are both common, and our whine on acceleration vs deceleration guide walks through how each one sounds.
Confirm the axle is a standard-rotation 8.8 rear. The 8.8 inch independent front axle on Explorers and F-150s is reverse rotation and needs reverse-cut gears, not this set; our Ford 8.8 IFS front differential guide covers that axle. Count the cover bolts (the 8.8 has ten, the smaller 7.5 has the same count, so also measure the ring gear or read the axle tag). Our axle ratio and code guide shows where Ford stamps the ratio on the tag and the door sticker. If the current ratio is already deep, like 4.10, think about whether you want to go taller: a 3.55 will drop cruise rpm but costs low-end pull. The Ford 8.8 3.73 set is the next step deeper if you are running bigger tires.
Revolution's fitment chart for this gear line lists the 1983-1996 Ford Bronco, 1997-2001 Expedition, 1991-2001 Explorer, 1979-2014 Mustang, 1990-2011 Ranger, 1987-1988 Thunderbird, 1979-1988 Mercury Cougar, 1975-1986 Grand Marquis, 1997-2010 Mountaineer, 2003-2004 Marauder, 1979-1983 Capri and 1994-2007 Mazda B3000 and B4000. Many other Ford trucks and cars used an 8.8 rear, but not every one is on that list, and 2015-up 8.8 axles use different face-hobbed gears. Ranger, Explorer and Mazda pickups were also built with the 7.5 inch axle, which does not take these gears. Match the 30-spline pinion, ten-bolt ring gear and tooth count to your old parts, or send us your year and VIN and we will check it. More Ford axle parts are on our hard parts page.
These are gears only. Order a full bearing kit with them, such as the Timken Ford 8.8 master bearing kit or the USA Standard 8.8 master overhaul kit; old pinion bearings rarely survive a new gear setup. The 8.8 is a C-clip axle, so remove the pinion shaft lock bolt and cross shaft, push the axles in and pull the clips before the carrier comes out. Revolution's setup chart for the 8.8 lists a 0.026 in starting pinion shim, 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. If you would rather not fight a crush sleeve, the Yukon 8.8 crush sleeve eliminator fits this axle. Check the drive and coast pattern, fill with 75W-140 or 75W-85 gear oil with friction modifier if it has Traction-Lok, and follow our ring and pinion break-in procedure. Common 8.8 failures and costs are covered in our Ford 8.8 rear axle problems guide.
| Brand | Revolution Gear & Axle |
| Part number | F8.8-355 |
| Fits | Revolution Gear & Axle Ford 8.8in Rear Axle 3.55 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.
No. Revolution lists this gear line with no carrier break, so the 8.8 carrier you have now takes the 3.55 as long as it is a standard-rotation 8.8 rear with the 30-spline pinion style.
No. The 8.8 inch independent front axle is reverse rotation and needs reverse-cut gears. This F8.8-355 is for the standard-rotation 8.8 rear axle only.
For a street car on stock-size tires coming from 2.73 or 3.08 gears, 3.55 gives noticeably quicker acceleration while keeping highway rpm manageable. Drag or autocross cars often go to 3.73 or deeper.
Yes, if you change ratios. Older cars need a different speedometer drive gear, and newer vehicles need the axle ratio reprogrammed in the computer with a tuner or scan tool. Same-ratio replacements do not need any change.
A Ford 8.8 master bearing or overhaul kit with pinion and carrier bearings, races, shims, crush sleeve and seal, new ring gear bolts, gear marking compound, and 75W-140 or 75W-85 gear oil plus friction modifier if the axle has Traction-Lok.
