Fluid Recommendation

Use hypoid gear lubricant SAE 80W or 90W.  On models with the front locking differential, add 2oz of friction modifier.  On models with the rear locking differential use only locking differential fluid part No. ESP-M2C154-A or it’s equivalent, and add 4oz of friction modifier.

The FX4 Level II Ford Ranger calls for 75W-140 synthetic lubricant.

Level Check

The fluid level in the drive axles should be checked at each oil change.  Like the manual transmission which is available, the rear axle does not have a dipstick to check fluid level.  Instead, a filler plug is located in the side of the housing (or in the side of the cover), at a level just barely above the level to which fluid should fill the housing. 

To Check The Fluid Level:

To check the front drive axle fluid level, loosen the fill plug …

… then remove it. Fluid should trickle out of the hole

If not, add the proper grade of lubricant until it does

To check the rear drive axle fluid level, loosen the fill plug …

… then remove it. Fluid should trickle out of the hole

If necessary, add the proper grade of lubricant until fluid trickles out

 1) Make sure the transmission is in P (A/T) or in gear on a manual, then FIRMLY set the parking brake and block the drive wheels.

2) Check under the vehicle to see if there is sufficient clearance for you to access the filler plug on the side of the differential housing. If not you will have to raise and support the vehicle using jackstands at four points to make sure it is completely level. Failure to support the vehicle level will prevent from properly checking or filling the drive axle fluid.

3) Thoroughly clean the area surrounding the fill plug. This will prevent any dirt from entering the housing and contaminating the gear oil.

4) Remove the fill plug and make sure that the gear oil is up to the bottom of the fill hole.  If a slight amount of lubricant does not drip out of the hole when the plug is removed, additional lubricant should be added.  Use hypoid gear lubricant SAE 80 or 90.

*lf the differential is a Traction-Lok limited-slip unit, be sure to use 4 oz. of Ford Friction Modifier C8AZ-l9B546-A or equivalent special limited-slip additive with the lubricant.

5) Once you are finished, install the fill plug, then (if raised) remove the jackstands and lower the vehicle.


Drain & Refill

Drain and refill the drive axle housings every 100,000 miles (160,000 km) or any time the vehicle is driven in high water (up to the axle).  Although some fluid can be removed using a suction gun, the best method is to remove the axle housing cover (if equipped) to ensure that all of any present contaminants are removed.  As with any fluid change, the oil should be at normal operating temperature to assure the best flow and removal of fluid/contaminants.

1) Drive the vehicle until the lubricant reaches normal operating temperature.

2)  If necessary for access, raise and support the vehicle safely using jackstands, but be sure that the vehicle is level so you can properly refill the axle when you are finished.

*lf a suction gun is used to drain the fluid, remove the fill plug and insert the suction tube into the fill hole until it rests at the lowest most point inside the housing. Operate the suction gun as per the manufacturers directions. When the fluid is completely removed, skip to the differential filling procedure.

Remove the fill plug, then clean the area around the axle housing cover to prevent dirt from entering it

3) Use a wire brush to clean the area around the differential. This will help prevent dirt from contaminating the differential housing while the cover is removed.

4)  Position a drain pan under the drive axle.

Loosen and remove all but two of the cover retaining bolts. Don’t lose the axle identification tag

5) Loosen and remove all but (2) of the housing cover’s upper or side retaining bolts.  The remaining (2) bolts should then be loosened to within a few turns of complete removal.  Use a small pry tool to carefully break the gasket seal at the base of the cover and allow the lubricant to drain.  Be VERY careful not to force or damage the cover and gasket mating surface.

With the remaining bolts loose, carefully pry out on the cover (to break the seal) and allow the fluid to drain

6.  Once most of the fluid has drained, remove the final retaining bolts and separate the cover from the housing.

To Fill The Differential:

7.  Carefully clean the gasket mating surfaces of the cover and axle housing of any remaining gasket or sealer.  A putty knife is a good tool to use for this.  You may want to cover the differential gears using a rag or piece of plastic to prevent contaminating them with dirt or pieces of the old gasket.

Remove any old gasket material from the sealing surfaces then clean them of any residual oil

8.  Install the housing cover using a new gasket and sealant.  Tighten the retaining bolts using a crisscross pattern.

*Make sure the vehicle is level before attempting to add fluid to the drive axle, otherwise an incorrect fluid level will result.

9. Refill the drive axle housing using the proper grade and quantity of lubricant.  Install the filler plug, operate the vehicle and check for any leaks.

Dana 35 SLA (1998-2011)

The 1998 and newer Ford Ranger uses a different style front axle assembly than the 1983-1997 models.

To check the fluid in these differentials, you have to remove the fill plug on the drivers side of the differential. Other than that, it’s a similar process to the other Ranger front axles.

I know it has a cover on the differential, but you can’t fully remove it with the differential still in the vehicle. There isn’t enough space in front of it to get the cover of. You’ll have to use a suction gun to get all of the fluid out, or lower the front differential from the vehicle.


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