97704 – Banks Dana M275 Ram-Air Rear Differential Cover

Part #s 19280, 19281, 19282

Banks Ram-Air® Differential Cover 2017+ Ford F250 HD Tow Pkg and F350 SRW, with Dana M275 Rear Axle

Please read through the following instructions thoroughly before starting your installation. If you have any questions please visit our Support Page.

Tools required:
  • Socket Wrench
  • Torque Wrench
  • 24mm Socket
  • 14mm Socket
  • 13mm Socket
  • 12mm Socket
  • 5mm Allen
  • Small Extension
  • Pry Tool
  • Puddy Knife
  • Wire Brush
  • Mallet
  • Clean Shop Towels


In some applications, our recommended fill level may not agree with the vehicle owner’s manual fill level. If this happens, honor the factory fill level, not Banks.


The primary purpose of the sight glass is to view the clarity of the gear oil, not to measure the fill level. Generally, the sight glass will display the correct fill level. However, in some applications, the proper fill level may be above or below the middle of the sight glass. The sight glass may not indicate the proper level if the truck is lifted or lowered, including factory off-road or heavy duty suspension packages. Changes in the pinion angle will result in the oil level above or below the sight glass. This is why we recommend filling to your truck’s factory recommended fill level.


General Installation Practices

1. Before starting work, familiarize yourself with the installation procedure by reading all of the instructions.

2. Disconnect the negative (ground) cable from the battery (or batteries, if there are two) before beginning work.

3. When raising the vehicle, support it on properly weight-rated safety stands, ramps, or a commercial hoist. Follow the manufacturer’s safety precautions. Take care to balance the vehicle to prevent it from slipping or falling. When using ramps, be sure the front wheels are centered squarely on the topsides; put the transmission in park; set the hand brake; and place blocks behind the rear wheels.

⚠️ CAUTION! ⚠️

Do not use floor jacks to support the vehicle while working under it. Do not raise the vehicle onto concrete blocks, masonry, or any other item not intended specifically for this use.

4. During installation, keep the work area clean. Do not allow anything to
be dropped into the rear differential while performing the installation, as foreign objects will cause immediate damage upon start-up.

General Assembly

Bill of Materials
Required Tools

Ram-Air Rear Diff Cover Installation

1 Install O-Ring

Apply a small amount of oil to the O-ring and slide the O-ring through your fingers to make sure it’s evenly coated.

Be careful not to damage the O-ring.

Depress the O-ring into the groove, slowly working your way around. If you find the O-ring to be slightly too long, take your time and walk the excess around the cover. You’ll slowly work the excess length into the groove as shown in the video above.

DO NOT CUT THE O-RING! Cutting the O-ring will result in a leak.

2 Place oil pan

Position an oil pan under the diff cover to catch fluids drained during installation.

Dana M275 Diff Cover drain

3 Drain Oil

This differential’s drain plug is the lowest diff cover bolt. Remove the drain plug using a 13mm socket and allow the fluid to fully drain from inside the axle housing.

Dana M275 Diff Cover Removal

4 Remove Cover

Use a 13mm socket to remove the remaining bolts and remove the cover. this may require a putty knife to pry up the cover. Avoid using a screwdriver as it may damage the face of the differential, causing a leak later.

Dana M275 Diff Cover cover gears

5 Cover Ring-Gear

Place clean shop towels or lint-free rags over the ring gear and differential to keep them clean.

Dana M275 Diff Cover clean surface

6 Clean Axle Surface

Clean and inspect the axle housing sealing surface. It should be flat and free of all debris, rust, residue, and sealant to ensure a proper O-ring seal. Use a putty knife or flat razor blade to remove all silicone residue.

7 Install Banks Cover

Install the Banks cover using the included bolts and a 13mm socket. Apply a small amount of thread locker on the bolts. Moving from bolt to bolt in a star pattern like you would when mounting a wheel, torque the bolts to 20 lb/ft (27 Nm).

8 Install Sight Glass

Install the sight glass using a 24mm socket. If the sight glass is already installed, make sure that it is tight and secure. Do not use a torque wrench as you will damage the O-ring.

Dana M275 Diff Cover drain plug

9 Install Drain Plug

If the drain plug is not already installed on the Ram-Air cover, apply a drop of diff fluid on the threads of the plug and install it now. Use a socket wrench to tighten. Do not use a torque wrench as over-tightening may damage the O-ring.

10 Fill with Oil

Fill the differential housing with the manufacturer’s specified amount and type of lubricant (refer to your vehicle’s owner’s manual) using a funnel or the new convenient AMSOIL Easy Packs. The fluid level should be at the center of the sight glass when the vehicle is parked on level ground.

Note: Fluid Level

Note: The fluid level may not appear in the center of the sight glass if the vehicle is parked on a hill, the chassis is raised by a jack or lift kit, or the suspension has been modified. The modifications affect the angle of the differential housing. This Ram-Air cover fits a wide range of Ford trucks with differing heights and wheelbases. Therefore, it’s possible that the factory-specified amount of lubrication will be above the center of the sight glass. This is NORMAL. Remember the main purpose of the sight glass is to check the fluid’s condition (color).

Dana M275 Diff Cover fill plug

11 Install Fill Plug

Apply a drop of diff fluid on the fill plug threads. Install the fill plug using a 14mm socket. Do not use a torque wrench as you can damage the O-ring.

12 Clean Up

Clean up any spilled oil and check for any leaks around the cover, fill/drain plugs, and sight glass.