Yukon Gear High Performance Gear Set For 10 & Down Ford 10.5in in a 4.11 Ratio
The Yukon YG F10.5-411-31 is a 4.11 ring and pinion for the 1999-2010 Ford 10.5 in. rear axle, the full-floating Sterling unit found under Super Duty F-250 and F-350 pickups, Excursions and E-Series vans of that era. Owners look for it when a truck that tows or runs taller tires feels flat off the line, when the stock gears have started to howl after years of trailer work, or when they want a deeper ratio than the 3.73 the truck left the factory with.
The 10.5 uses a large 10.50 in. ring gear held by 12 bolts, driven by a 31-spline pinion in these 2010-and-earlier housings. The ratio sets how many times the driveshaft turns for each turn of the wheels. Moving from 3.73 to 4.11 raises torque at the tires about 10 percent, which helps a loaded truck get rolling and lets the transmission stay in higher gears on grades. Because the 10.5 is full floating, the axle shafts carry no vehicle weight, so the ring and pinion and the pinion bearings take the abuse when the truck is worked hard.
Confirm the axle is the 10.5 and not the 10.25 used in earlier Fords, and check the ratio tag or door code; our guide on finding your rear axle ratio and axle code walks through it. If the problem is noise, separate gear whine from bearing growl with this whine diagnosis. The Ford Sterling 10.5 problems and rebuild cost guide covers the common failures.
Fits 1999-2010 Ford 10.5 in. axles with the 31-spline pinion. Distributor charts list both the 2007-and-older and the 2008-2010 housing groups for this part number. It does not fit 2011 and newer Super Duty 10.5 axles, which use a 37-spline pinion and need the separate 37-spline 4.11 set (YG F10.5-411-37). If you want more reduction for 37 in. tires, see the 4.88 version. Send us your year and VIN if you are unsure. More rear-axle gear sets are in the hard parts collection.
Yukon's set-up chart for the Ford 10.25 and 10.5 lists a 0.025 in. OEM pinion shim depth, 20-35 in-lb of pinion bearing preload with new bearings, 95 ft-lb on the ring gear bolts and 80 ft-lb on the bearing caps. Set backlash, then read the contact pattern before closing it up. Replace the bearings, races, seal and crush sleeve at the same time; the Yukon master overhaul kit for 2007-and-older 10.5 or the Revolution 10.25/10.5 master install kit has the parts. Fill with 75W-90 or 75W-140 gear oil, add friction modifier if the truck has a clutch-type limited slip, drive gently for the first miles and avoid towing until the gears are broken in. Yukon lists 37 in. as the maximum recommended tire for the Ford 10.25 family.
| Brand | Yukon Gear & Axle |
| Part number | YG F10.5-411-31 |
| Fits | Yukon Gear High Performance Gear Set For 10 & Down Ford 10.5in in a 4.11 Ratio |
| Type | Final Drive Gears |
| 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. 2011 and newer Ford 10.5 axles use a 37-spline pinion. This set is the 31-spline version for 1999-2010 axles.
Distributor fitment charts list both housing groups for this part number. Send us your year and VIN if you want us to double check.
Yes. The ring gear bolts to your existing 10.5 carrier. Clean it, check the side bearings, and add friction modifier to the gear oil if it is a clutch-type limited slip.
Pinion and carrier bearings and races, the pinion seal, crush sleeve and shims. A 10.5 master overhaul or master install kit covers them.
Yukon lists 20-35 in-lb new pinion bearing preload, 95 ft-lb ring gear bolts and 80 ft-lb caps for the Ford 10.25 and 10.5.
