One of the quickest ways to add functionality and a touch of flair to your pickup is by replacing the boring, stock, stamped-steel differential cover with a machined-aluminum unit. While there is nothing wrong with the factory piece, aftermarket covers often add fluid capacity, increase cooling ability, improve strength, and look great when viewed from behind. Whether you favor off-roading, do a lot of heavy towing, or just cruise the streets, your truck will benefit from longer oil life and cooler operating temperatures.
Mag-Hytec has been in the business of diff covers for more than 20 years and has been manufacturing parts for the aerospace industry for nearly half a century. All of the company’s products are cast from T6 aluminum, machined to the proper specifications, and finished with a durable, textured black powdercoat. They feature a magnetic dipstick and drain plug, which in addition to enabling quick fluid changes, also work to catch and hold onto any metallic debris that may be found in the fluid. Rubber O-rings replace paper gaskets or RTV for a leak-free seal. And all covers are warrantied for life.
With these benefits in mind, we ordered a rear cover for our 2013 Ford F-150 Raptor. Mag-Hytec has differential applications that cover nearly all popular Ford, GM, Ram, and Nissan pickups along with transmission pans for Ford, GM, and Ram. Installation is simple and the included instructions are straightforward.
| When we moved the factory spare tire on our 2013 Ford F-150 SVT Raptor from under the bed to in it, it provided a direct line of sight to the rear axle. Knowing we wanted a more pleasing look and added strength, we opted for a new cover from Mag-Hytec.
| Mag-Hytec casts all of its differential covers and transmission pans from A356-T6 aluminum. They feature machined cooling fins and a textured black powdercoat finish. All of the company’s products are proudly built in the USA.
| The cover for our Ford 9.75-inch axle came fitted with a fill/reference port, drain plug, and dipstick. Instead of using nasty RTV to seal the cover to the axlehousing, Mag-Hytec fits each of its covers with an ARP 568 O-ring. New bolts and washers are provided as well and are 303 stainless steel.
| ARP 568 O-ring
| Before starting the installation, we gathered the fluid required to fill the axle. The Mag-Hytec cover holds approximately 5 quarts, and we settled on Amsoil’s Severe Gear 75W-110. Amsoil has formulated its Severe Gear line to better cope with the rigors of off-road use and heavy towing than conventional gear lube and recommends a drain interval of between 50,000 and 100,000 miles, depending on use.
| Our F-150’s factory stamped-steel differential cover had served us well for half a decade. However, the years of use and abuse left us with kind of an eyesore. Instead of merely cleaning and painting the cover, we opted to add a touch of class to our rear end.
| The task is a fairly straightforward remove-and-replace job. If applicable, we suggest removing the spare tire to allow more room to work. We began by placing a fluid catch pan below the differential and slowly removed the bolts holding the factory cover to the axle.
| Ford’s 9.75-inch axle uses 12 bolts to secure the differential cover. Before breaking the seal, we suggest removing 10 of the bolts and leaving two near the top in place (but loose). This will help moderate the flow of fluid out of the housing and keep the cover from falling off.
| Loosening the RTV seal can take either a solid hit with a dead-blow hammer or a gentle pry at one of the edges. Care must be taken to not nick or otherwise damage the sealing surface. Once the seal breaks, slowly drain the old fluid into an appropriate receptacle before fully removing the old cover.
| With the oil drained, we cleaned the remaining grime out of the housing using brake cleaner and removed the excess RTV from the sealing surface with a plastic gasket removal tool as to not damage the metal surface. This surface needs to be flat and true for the new O-ring to seal properly.
| After applying a thin film of oil to the O-ring, we installed the Mag-Hytec cover by first hand-tightening the 12 hex-head fasteners. Next, working in a crisscross pattern, we tightened the fasteners to the appropriate 16 ft-lb of torque. Thread-locking compound was applied to the fasteners, but a dab of RTV on the threads will serve the same purpose.
| With Amsoil’s new Easy-Pack quarts, gone are the days of fumbling with rigid bottles, pumps, and hoses to fill axlehousings. The flexible fluid sacks are easy to manipulate in tight areas, giving more control and, ideally, less mess to clean up.
| The installation took us two hours from start to finish, including cleaning and painting the axlehousing. If you just change the cover and are well prepared with no distractions, the whole job can be done in as little as half an hour in the driveway with basic handtools. To us, the payoff is huge for the amount of time and money invested.
In an attempt to slow the influx of hate mail, let’s address the elephant in the room. Yes, we are fully aware of the testing being performed by others in the industry. As of publication, their testing is incomplete and inconclusive. While we don’t dispute the merits of their testing process or data shown thus far, we choose to view the subject with open minds and the knowledge that in our 20 years in the industry we’ve not witnessed any mechanical failure attributed to an increase in lubricant or change in flow pattern. As information becomes available, we’ll continue to evaluate our stance on the matter.