The point of the Banks Ram-Air Differential Cover Kit is simple: get heat out of the differential and manage the oil better while you’re in there. Instead of a flat-back cover that mostly adds material, this design uses Ram-Air scoops and external cooling fins to move air across the cover as the truck drives. Inside, the fin structure helps direct lubricant through the housing so the gears stay supplied with oil instead of letting fluid just slosh around. We also built in the service features that matter on a working truck, including a sight glass, upper fill plug, lower drain plug, and an O-ring seal. That gives you a differential cover that improves cooling, helps lubricant control, and makes maintenance easier.
The video covers installation of a Banks rear differential cover on a 2018 L5P Duramax. Before this step, the truck had already received the steel rear component referenced by the installer, and the remaining parts for this job included the Banks cover, new bolts with thread locker already applied, and AMSOIL Severe Gear 75W-90 fluid. The tools used were straightforward: a torque wrench, sockets, a cordless impact, brake clean, and shop rags.
The installation is presented as a simple service-and-upgrade procedure rather than a major teardown. One person performs the work while the other explains the process, with the focus on draining the axle, removing the factory cover, preparing the sealing surfaces, installing the Banks unit, and refilling the differential.
The first step is to remove the drain plug at the bottom of the differential and let the old gear oil drain out. While the housing is draining, the factory differential cover bolts are removed using a cordless impact and a 13 mm swivel socket. A bracket attached near the cover is lifted slightly out of the way so the bolts can be accessed.
One upper bolt is intentionally left threaded in by a couple of turns. That keeps the stock cover from dropping unexpectedly when the seal is broken loose. With the remaining bolts removed, a flat-blade scraper is worked into the seam to pop the cover free. Once the seal breaks, the cover can be pulled down and removed in a controlled way.
With the factory cover off, the video briefly compares it to the Banks replacement. The Banks cover is shown to have substantially more cooling fin area, along with directional features intended to manage airflow. This particular unit is the Black Ops edition, so the fins are painted rather than polished.
The external features highlighted include a fill plug on top, a drain plug on the bottom, and a clear sight glass that allows fluid condition and level to be checked during service life. The installer also points out the internal fin structure seen earlier in the video, noting that Banks uses those internal features to help direct and deflect the gear oil throughout the housing.
Before the new cover goes on, the inside of the differential housing is cleaned with brake clean to flush out remaining old fluid and residue. The goal is to start with a clean housing rather than trapping contaminated oil behind the new cover.
The new sealing ring on the Banks cover is then prepared with a very thin coat of fresh 75W-90 gear oil. The installer emphasizes using only a light film of oil around the sealing ring. During this stage, the drain plug is also reinstalled and snugged so it is not forgotten later in the process.
Once the seal is lubricated and the housing is ready, the Banks differential cover is positioned on the axle and a couple of bolts are started by hand to hold it in place. The supplied hardware uses 12-point 10 mm bolts, so a 12-point socket is required for installation. One of the bolts must pass through the bracket that was moved aside during removal.
The bolts are then run in gradually in a star-pattern sequence to seat the cover evenly against the housing. This helps avoid uneven loading on the seal. The instructions call for 12 ft-lb of torque on the cover bolts, and the installer switches from the impact to a torque wrench set to that value for final tightening. Medium-strength blue Loctite is used, and the video notes that Banks supplied a packet for the job.
After the cover is torqued, the differential is refilled with AMSOIL Severe Gear 75W-90 synthetic gear oil. The Banks cover is described as making this process easier because the fill plug is located at the upper portion of the cover and the lower sight glass provides a convenient visual reference while filling.
Once the proper level is reached, the fill plug is installed to complete the service. The combination of the upper fill location and the sight glass is presented as a practical improvement over a more awkward stock fill process.
The closing discussion focuses on why the Banks cover is different from the stock part. The external cooling fins are shaped to take advantage of airflow as the truck moves down the road. According to the installer, air is brought up through the inner scoops and across the finned structure to help dissipate heat that builds up in the rear differential housing.
The internal fins are intended to do more than add surface area. They are described as helping direct and deflect the gear oil throughout the housing, improving how the lubricant is distributed inside the differential. In the recap presented by the installers, the Banks cover combines easier servicing features with added cooling capacity and more deliberate fluid management inside the axle.