Yukon Gear High Performance Gear Set For GM 8.25in IFS Reverse Rotation in a 4.11 Ratio
Lifted half-ton GM trucks on much larger tires usually end up at 4.11 or deeper, and the front axle has to be re-geared along with the rear. The Yukon Gear & Axle YG GM8.25-411R is a 4.11 ring and pinion for the GM 8.25 in. IFS front differential found on 4WD Silverado 1500, Sierra 1500, Tahoe, Suburban 1500, Yukon and Avalanche models. It is the deeper option between the 3.73 and 4.56 sets we carry for the same front.
The 8.25 IFS is a reverse rotation front: the pinion sits high on the ring gear so the drive side of the teeth carries the load when the truck pulls forward in 4WD. That is why the part number ends in R, and why a standard rotation 8.25 gear set cannot be used here. Yukon lists this set with an 8.25 in. ring gear, a 30 spline pinion and 10 ring gear bolts.
Going to 4.11 from a factory 3.08 or 3.42 brings rpm back up after a tire upgrade, so the transmission stops hunting between gears and the truck pulls from a stop again. Yukon's spec table files the part under a 4.10 gear ratio, so it pairs with a 4.10 rear set.
This is the most common ordering mistake on these trucks. Yukon's technical note says 8.25 IFS fronts that left the factory with 3.08 gears need a new carrier when changing ratio: the 3.08 carrier has a 1.780 in. deck height and the 3.42-and-up carrier is 1.920 in. Because 4.11 is past that break, a truck that came with 3.08s needs carrier YC G26018131 along with this gear set. Trucks that came with 3.42 or deeper can reuse their carrier. Our carrier break guide explains why, and the factory ratio is in the RPO codes on the glovebox label.
Compare the noise in 2WD and 4WD High, and check whether the front actuator is engaging. Our GM 8.25 IFS front differential problems guide covers actuator and bearing failures that sound like gears. Confirm the current ratio before ordering so the front and rear end up matched.
Yukon describes this set as fitting 2013-and-earlier GM 8.25 IFS fronts. The retailer fitment chart also lists 1988-1998 K1500 and Tahoe fronts and some 2014-2017 half-ton trucks and SUVs, split into 1998-and-older, 1999-2009 and 2010-and-newer front housing groups. Because the two listings do not agree on late years, send your year and VIN before ordering for a 2014-up truck, and match the 30 spline pinion and 10-bolt ring gear on your old set. It does not fit 2500 and 3500 trucks, which use the larger 9.25 IFS front.
Other ratios for the same front: the 3.73 reverse set and the 4.56 reverse set. More axle parts are in differential hard parts.
The front differential comes out of the truck for a gear change. Order the Yukon 8.25 IFS master overhaul kit or the Dorman 697-034 bearing kit with the gears, since bearings are not included. Yukon's setup chart for the 8.25 IFS lists a .037 in. OEM depth shim, 14-19 in-lb pinion bearing preload with new bearings, 65 ft-lb ring gear bolts and 55 ft-lb bearing caps. Carrier preload and backlash are set with the threaded side adjusters, which take a spanner tool. Check the pattern on both drive and coast sides.
Fill with 75W-90 gear oil. Keep it out of 4WD and off heavy loads during break-in, and change the oil after the first 500 miles.
| Brand | Yukon Gear & Axle |
| Part number | YG GM8.25-411R |
| Fits | Yukon Gear High Performance Gear Set For GM 8.25in IFS Reverse Rotation 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. Yukon notes that 3.08 fronts need a 3.42-and-up carrier (YC G26018131) for any deeper ratio, because the deck height changes from 1.780 in. to 1.920 in.
No. Heavy-duty 2500 and 3500 trucks use the 9.25 IFS front. This set is for the half-ton 8.25 IFS.
Yukon's specification lists this part as a 4.10 gear ratio, so it is meant to run with a 4.10 rear. The two axles must match or the transfer case binds in 4WD.
A master overhaul kit for the 8.25 IFS with pinion and carrier bearings, races, shims, crush sleeve and seals. Replace the axle seals while the differential is out.
Yukon lists the set for 2013-and-earlier fronts, while the retailer chart includes some 2014-2017 trucks. Send your year and VIN and we will confirm before you order.
