Yukon Gear High Performance Gear Set For 10.5in GM 14 Bolt Truck in a 4.11 Ratio

Yukon part number YG GM14T-411 is a high-performance 4.11 ring and pinion for the GM 10.5 inch 14-bolt full-floating rear axle. Yukon's fitment list runs from 1973 through 2015 and covers C/K 20 and 30, 2500 and 3500 pickups, 2500 Suburbans and Yukon XLs, Silverado and Sierra 2500 HD through 2015, 3500 and 3500 HD trucks, P-series step vans, and Express and Savana 2500, 3500 and 4500 vans. People shopping for this set usually have a 3/4 or 1 ton that came with 3.42 or 3.73 gears and now runs bigger tires or tows heavy. The other group has a high-mileage 14-bolt with a gear whine and wants new gears in the ratio the truck should have had from the start.

What the ring and pinion does in a GM 14-bolt

The 14-bolt 10.5 is a full-float axle. The hubs ride on their own bearings on the axle tubes, and the shafts only carry torque. That leaves the ring and pinion doing the heavy work. The pinion in this set has 30 splines and is held by a pair of tapered bearings plus a pilot bearing at the nose, inside the housing. That third bearing is why the 14-bolt pinion stays so stiff under load. The 10.5 inch ring gear bolts to the carrier with 12 bolts. A 4.11 ratio turns the driveshaft 4.11 times for each wheel revolution. At 65 mph on a 35 inch tire that works out to roughly 2,565 engine rpm in a 1:1 gear (mph x ratio x 336 / tire diameter), before overdrive brings it down.

Symptoms of worn 14-bolt gears

• Whine that comes in at a certain speed and changes between drive and coast. That points to the gear contact, not the bearings.
• Growl or rumble that holds steady on and off the throttle, which usually means pinion or carrier bearing wear. That is the 14-bolt's most common failure.
• Fluid at the pinion seal or on the inner face of a tire. A leaking seal starves the pinion bearings and ruins the gears.
• Metal on the drain plug, or chipped teeth you can see through the cover opening.
• A truck that struggles to hold top gear when towing after a tire size change.

How to confirm before you buy

Make sure the axle is a 14-bolt 10.5 and not the AAM 11.5. Many 2001-and-later 2500 HD and 3500 trucks got the AAM axle, and both have 14-bolt covers. Read the axle tag or the RPO codes on the glovebox sticker. Measure the ring gear if the cover is off. Then confirm where the noise comes from. A rear axle whine is easy to blame on the transmission in these trucks. Our 4L80E noise diagnosis guide shows how to separate the two with a driveshaft-off test.

Fitment and carrier

Yukon's note on this set reads: fits the 3-series, 4.10-and-down carrier. GM built the 14-bolt in four generations: 1988 and older (except 1984-1985), 1984-1985 only, 1989-1998, and 1999-and-up. This gear set fits all four, but bearings, install kits and some pinion parts differ between them. A truck that came with 3.42, 3.73 or 4.10 gears already has the right carrier. A carrier built for 4.56 and deeper ratios takes a thicker gear such as our 14-bolt 5.38 thick set, not this one. If you are adding traction at the same time, the Dura Grip posi for the 4.10-and-down 14-bolt matches this gear. Send us your year and VIN and we will confirm the axle before you order.

Install notes

Yukon's setup chart for the 14T 10.5 with pinion support lists 20-35 in-lb of pinion bearing preload with new bearings, 8-11 in-lb with used bearings, 0.006-0.011 in. of backlash, 120 ft-lb on the ring gear bolts and 135 ft-lb on the carrier caps. The 14-bolt carrier is preloaded with threaded adjusters, so plan on setting backlash from both sides and then rechecking the pattern with marking compound. Replace every bearing at the same time. For 1999-and-up axles the Yukon YK GM14T-C master overhaul kit supplies the bearings, races, shims and seals. Older trucks take the YK GM14T-A kit for 1988 and older. A crush sleeve eliminator makes preload easier to set and to hold on a truck that tows.

Fill with 75W-90 or 75W-140 gear oil to the bottom of the fill hole. Use the heavier oil if the truck tows a lot or works in heat. Then follow Yukon's break-in steps: drive lightly for 15-20 miles and let the axle cool, avoid hard acceleration for 100 miles, no towing for the first 500 miles, then change the oil. For the first tow, pull the full load less than 15 miles, then cool for 20 minutes, and repeat that twice. Reprogram the axle ratio afterward so the speedometer and shift points are correct.

Does this fit my 2500 HD with the 11.5 inch rear?

No. The AAM 11.5 used in many 2001-and-later GM 2500 HD and 3500 trucks also has a 14-bolt cover, but it is a different axle with a larger ring gear. This set is only for the GM 10.5 inch 14-bolt. Check the axle tag or send us your VIN.

Is a 4.11 the same as a factory 4.10?

It works the same way and fits the same 3-series carrier. Yukon cuts the set at 4.11 instead of 4.10, which is too small a difference to notice in rpm or speedometer error. Still reprogram the ratio after the swap.

My truck came with 4.56 gears. Can I use this set?

Not with your current carrier. Yukon specifies this set for the 3-series carrier built for 4.10-and-lower ratios. A factory 4.56 or 5.13 truck has the deeper-ratio carrier, which needs a thick gear or a carrier swap.

What should I replace with the gears?

Replace the pinion bearings, the pinion pilot bearing, the carrier bearings, the races, the pinion seal and the crush sleeve or solid spacer. Check the axle shaft seals and hub bearings too. 14-bolts often leak there, and gear oil on the brakes ruins the shoes.

What gear oil does a 14-bolt use after new gears?

Use 75W-90 for general driving or 75W-140 for heavy towing. Change it after the first 500 miles to remove break-in particles, as Yukon recommends.