Yukon Gear Chrome Cover For 10.5in GM 14 Bolt Truck

If the rear cover on your Chevy or GMC 3/4-ton or 1-ton is rusted through at the bottom, dented from a rock, or weeping gear oil around a warped flange, this is the direct replacement. The Yukon YP C1-GM14T is a chrome cover shaped for the GM 10.5 inch 14-bolt full-floating rear axle found under C/K 2500 and 3500 pickups, 2500 Suburbans, Express and Savana vans, and 2001-2015 Silverado and Sierra 2500 HD trucks that carry the 14-bolt. It bolts on with your existing hardware and gives the axle a clean, bright finish that is easy to inspect for leaks.

What the cover does on a GM 14-bolt

The 14-bolt gets its name from the fourteen bolts that hold this cover to the housing, not from the ring gear, which is fastened with twelve. The cover closes the back of the carrier, holds the gear oil that the ring gear slings onto the pinion and carrier bearings, and is the only place you can open the axle for a fluid change or inspection without pulling the third member. On a full-floater the hubs ride on their own bearings, so the oil in this housing is doing most of its work on the ring and pinion and the large pinion bearings. A cover that leaks lets that oil level fall, and low oil on a 14-bolt shows up as the pinion and carrier bearing wear and gear whine these axles are known for.

Signs your 14-bolt cover needs replacing

• Wet, dirt-caked gear oil around the cover flange or dripping from the lowest bolts
• Rust scale or pitting at the bottom of the cover where water and salt sit
• A dent or crease from rocks, a hitch, or a jack placed on the cover
• Stripped or pulled bolt holes after repeated fluid changes
• Gear whine that started after a leak was ignored and the fluid ran low

How to confirm the cover is the problem

Clean the housing with brake cleaner, drive a few miles, and look for fresh oil. Oil that starts at the cover seam is a cover or gasket problem; oil coming from the pinion yoke or running down the inside of a wheel points to a pinion seal or hub seal instead, and a new cover will not fix it. Our guide to fixing a diff cover leak with a gasket or RTV walks through the check. If the axle is already noisy, read GM 14-bolt rear axle problems and rebuild cost before you close it back up, because a howl usually means bearings, not the cover.

Fitment

Yukon catalogs this cover for the GM 10.5 inch 14-bolt truck axle from 1973 through 2015, covering every generation they list: the 1973-88 design, the 1984-85 version, the 1989-98 axle and the 1999-up axle. That includes C/K, R/V and 2500/3500 pickups and Suburbans, G20/G30 vans, 1996-2015 Express and Savana 2500 and 3500 vans, 2009-2015 Express and Savana 4500, P30 chassis, 2002-2006 Avalanche 2500, 2000-2013 Suburban 2500 and Yukon XL 2500, and 2001-2015 Silverado and Sierra 2500 HD.

Two checks before you order. First, count the cover bolts and measure the ring gear: the 9.5 inch semi-float axle used in half-ton trucks also has a 14-bolt cover but is a different, smaller pattern. Second, many 2001-up HD pickups and every third-generation Ram 2500/3500 use the AAM 11.5 inch axle, which looks similar but needs the AAM 11.5 cover. If you are unsure, send us the year and VIN and we will confirm before it ships. More parts for this axle are in our hard parts section.

Install notes

• Drain the axle by loosening the cover from the top bolts down, then scrape the housing flange to bare, clean metal. Old gasket material left on the flange is the most common reason a new cover leaks.
• Seal it with a new cover gasket or a thin bead of gear-oil-rated RTV run inside the bolt holes. With RTV, let it skin over before you fill.
• Reuse your bolts if the threads are clean. Early and late 14-bolt housings use different bolt sizes, which is why Yukon sells its heavy cast covers in 3/8 inch and 8 mm bolt versions. Tighten in a cross pattern so the flange pulls down evenly.
• Refill through the fill plug with 75W-90 or 75W-140 gear oil until it reaches the bottom of the fill hole, and add friction modifier only if the axle has a clutch-type limited slip.
• With the cover off, look at the oil and the magnet. Bronze or steel paste means bearings are going; a 14-bolt axle bearing and seal kit or a 14-bolt minor install kit is cheaper now than after the gears are damaged.

The chrome finish is cosmetic and resists surface rust well, but it is the stock shape and thickness, not an armor cover. If you run rocks or trails, the cast covers linked above are the better choice. For a work truck, van or show build that just needs a straight, dry cover, this one does the job.

Will this cover fit my 2005 Silverado 2500 HD?

Only if the truck has the GM 10.5 inch 14-bolt. Yukon lists 2001-2015 Silverado and Sierra 2500 HD with the 14-bolt, but many HD trucks from 2001 on have the AAM 11.5 inch axle instead, which takes a different cover. Look for the ring gear size on the axle tag or send us your VIN.

Does the cover come with a gasket or bolts?

The listing is for the cover only. Plan on a new cover gasket or gear-oil-rated RTV, and reuse your original cover bolts if the threads are clean.

Will it fit the 9.5 inch 14-bolt from a half-ton?

No. The 9.5 inch semi-float axle also uses 14 cover bolts, but it is a smaller housing with a different bolt pattern. This cover is for the 10.5 inch full-floating truck axle.

What gear oil goes in a 14-bolt after the cover is installed?

Fill with 75W-90 or 75W-140 gear oil to the bottom of the fill plug hole. Add limited-slip friction modifier only if your axle has a clutch-type limited slip.

My axle whines. Will a new cover stop it?

No. A cover fixes leaks, rust and dents. Whine on a 14-bolt usually comes from pinion or carrier bearing wear, often after the fluid ran low, and needs a bearing kit or overhaul.