Repair rear differential seal on 2005 mercury mountaineer

cv shafts come in different lengths , left to right vehicle to vehicle
indicate a shaft too short to properly fit in the splines in the side gears of the differential

Mercury Monterey 2004 2007 Factory Service SHop repair manual Download

for the easy solution download the pdf file

remove the brake caliper and rotor then undo the axle nut and disconnect the lower ball joint and separate from the spindle assembly. pull the outer cv joint out from the spindle and pull out the half shaft. you may have to remove the speedometer drive gear before removing the half shaft. installation in reverse order.

The CV axle stub (end with the axle nut on it) supports the wheel bearing, removing the axle then driving on it would cause the bearing to wear prematurely. I would not recommend this. The front differential is also sealed by the cv assembly, removing it would cause the diff fluid to leak out . CV shafts for this van run $50-80. I would replace if it is bad, instead.

You would have to ask any cost questions ,on any vehicle
repairs,to the merchant or shop of your choice

There is no set price

Every shop has different labor rates & skill
set levels.

Axle Vent
NOTE: If the vent cannot be cleared, it must be installed new.
A plugged vent will cause excessive seal lip wear due to internal pressure buildup. If a leak occurs, check the vent. Make sure the vent hose is not kinked. Remove the hose from the vent nipple and clear the hose of any foreign material. While the hose is removed, pass a length of mechanics wire or a small diameter Allen wrench in and out of the vent to clean it. Connect the hose when done. The vent is located on the drivers side top of axle housing.
If you plan on doing most repairs yourself I would suggest buying a Haynes or Chilton manual for your particular vehicle. Or there are some data disks on e.bay($12-$15) For a cost of under $25, you can almost do any repair yourself with these manuals.Also there are online manuals like the site called ALLDATA where guides can be viewed for a fee. All these solutions will save you time and money, and give peace of mind over correct repairs. I can post you some procedures here also.

1. CAUTION: Do not use heat to loosen a seized lug nut. Heat can damage the wheel (1007) and the rear wheel bearings (1225).
2. Loosen the lug nuts (1012).
3. Remove the center cap.
4. With the weight of the vehicle on the wheels, loosen the lug nuts Raise and support the vehicle. .Remove the wheel and tire assembly.
   
5. Remove the lug nuts.
   
6. Remove the wheel and tire assembly. Remove the axle housing cover (4033).
   
   1. Loosen the axle housing cover bolts (4346) and drain the rear axle (4001).
   1. Remove the axle housing cover bolts.
   1. Remove the axle housing cover.
   

7.Remove the rear disc brake rotors You will have to remove the brake caliper to get rotor off.
8. CAUTION: Once the differential pinion shaft (4211) has been removed, turning the differential case (4204) or an axle shaft (4234) will cause the differential pinion gears (4215) to fall out of the assembly. This could result in chipped or damaged components.
9.
1.Remove the differential pinion shaft lock bolt. 2.Remove the differential pinion shaft. 10.CAUTION: Do not damage the rubber O-rings in the U-washer grooves. Remove the U-washers (4N237).

1. Push the axle shafts inboard.
2. Remove the U-washers.

11.Reinstall the differential pinion shaft.
1. Install the differential pinion shaft.
1. Install the differential pinion shaft lock bolt finger-tight.

12.CAUTION: Do not damage the inner wheel bearing oil seal (1177). Remove the two axle shafts.

CAUTION: Never remove the axle shaft oil seal by itself. Always remove the rear wheel bearing and the axle shaft oil seal at the same time. NOTE: If the axle shaft oil seal is leaking, the axle housing vent may be plugged with debris. Use Impact Slide Hammer and Axle Wheel Bearing Puller to remove the rear wheel bearing and the axle shaft oil seal.

Axle bearing puller end..
Installation
Lubricate the lip of the inner wheel bearing oil seal.
Use Premium Long-Life Grease XG-1-C or equivalent meeting Ford specification ESA-M1C75-B.

1. CAUTION: Once the differential pinion shaft has been removed, turning the differential case or an axle shaft will cause the differential pinion gears to fall out of the assembly. This could result in chipped or damaged components.
2. Remove the differential pinion shaft.
3. Remove the differential pinion shaft lock bolt.
4. Remove the differential pinion shaft.

CAUTION: Do not damage the inner wheel bearing oil seal. Install the two axle shafts. CAUTION: Do not damage the rubber O-rings in the U-washer grooves. Install the U-washers.
1. Position the two U-washers on the button end of the axle shafts.
1. Pull the axle shafts outward.

Install the differential pinion shaft.
1. Align the hole in the differential pinion shaft with the differential pinion shaft lock bolt hole.
1. Install the differential pinion shaft lock bolt.

Install the rear disc brake rotors; Install the axle housing cover and fill the rear axle housing (4010) with 2.4 liters (5.5 pints) of specified lubricant
WARNING: Always remove any corrosion, dirt or foreign material that may be present on the mounting surfaces of the wheel or the surface of the wheel hub or rear disc brake rotor that contacts the wheel. Installing wheels without proper metal-to-metal contact at the wheel mounting surfaces can cause the lug nut to loosen and the wheel to come off while the vehicle is in motion, causing loss of control. Clean the wheel hub and mounting surfaces. Install the tire and wheel assembly.
Position the tire and wheel assembly. Install the lug nuts and lower the vehicle. Tighten the lug nuts. Install the center cap. WHEW Hope this can help you

It's in the rear differential under the yolk where the propeller shaft(Drive Shaft) connects to it!
Have a Nice Day!! GMJ

That will be a Huge job. The whole front diff must come out of the car and the case will need to be taken apart to even gain acess to the carrier side bearings.
The hub bearing is where the wheel bolts up is that maybe what you are talking about?
Also the axle seal isn't that bad to do you need to remove the cv shaft then it's just a simple remove the seal and install the new one.
But all of these jobs will be big ones.

I cannot see it, but I am guessing that you need to replace your axle seal. To do this,you have to pull your CV shaft out. Remove the tire, remove the caliper from the top of the rotor. Using a hammer on the back, remove the rotor. Take off the spindle (axle) nut, separate the axle (CV shaft) from the hub. Replace seal. It should pop right out. Good luck!

Dana or Ford axle?

Ford here:
SECTION 205-05: Rear Drive Halfshafts 2002 Explorer/Mountaineer Workshop Manual
REMOVAL AND INSTALLATION Halfshaft
Special Tool(s) Protector, Differential Seal
205-506 Remover, Front Wheel Hub
205-D070 (D93P-1175-B) or equivalent Remover, Halfshaft
205-502
Removal and Installation
NOTE: This procedure applies to both rear halfshaft assemblies.

1. CAUTION: Do not loosen the rear axle wheel hub retainer until after the wheel and tire assembly are removed from the vehicle. Wheel bearing damage will occur if the wheel bearing is unloaded with the weight of the vehicle applied.
   With the vehicle in NEUTRAL, raise and support the vehicle. For additional information, refer to Section 100-02 .

1. Remove the rear wheel and tire assembly. For additional information, refer to Section 204-04 .

1. NOTE: Have an assistant press the brake pedal to keep the axle from rotating.
   Remove and discard the rear axle wheel hub retainer and the washer.

1. CAUTION: To prevent damage to the brake hose, do not allow the disc brake caliper to hang suspended from the hose.
   Remove the brake disc.
   1. Remove the two bolts and lift the disc brake caliper and brake pads off the brake disc.
      • Using mechanics wire, position the disc brake caliper out of the way.
   1. Remove the brake disc.

1. Remove the bolt retaining the parking brake cable bracket to the frame.

1. CAUTION: Cover the stabilizer link bolt threads and the nut to prevent boot damage when removing the halfshaft assembly from the vehicle.
   Using a rubber hose approximately 37.5 mm (1.5 in) long, cover the stabilizer link bolt threads and nut.

1. WARNING: The bolt that retains the upper ball joint to the knuckle is longer and it has fewer threads than the bolt that retains the toe link to the knuckle. Switching these bolts during installation will prevent the pinch arms on the knuckle from correctly retaining the toe link to the knuckle. This may cause the toe link to separate from the knuckle during vehicle operation. Failure to follow these instructions may result in personal injury.
   Remove the pinch bolts and disconnect the toe link and upper ball joint from the knuckle.

1. CAUTION: Support the rear suspension upper arm to prevent boot damage when removing the halfshaft assembly from the vehicle.
   Using a wood stick, approximately 450 mm (18 in) long and 25 mm (1 in) wide, support the rear suspension upper arm.

1. CAUTION: Do not use a hammer to separate the outboard CV joint from the hub. Damage to the threads and internal CV joint components may result.
   CAUTION: Once the outboard CV joint separates from the hub the knuckle will continue to pivot until the brake backing plate presses against the suspension lower arm. To prevent damage to the brake backing plate, immediately after separating the outboard CV joint from the hub, rest the knuckle on a cushioned support that is tall enough to keep the backing plate from pressing against the suspension lower arm.
   Separate the outboard CV joint from the hub and rest the knuckle on a cushioned support.
   1. Using the special tool, press the outboard CV joint until it is loose in the hub.
   1. Remove the special tool.
   1. Separate the outboard CV joint from the hub.
   1. Rest the knuckle on a cushioned support.

1. CAUTION: Do not damage the axle shaft oil seal or the machined sealing surface on the inboard CV joint housing.
   CAUTION: Do not allow the splines on inboard CV joint housing to touch the axle shaft oil seal.
   NOTE: A circlip retains the inboard CV joint housing to the differential side gear in the axle.
   Using the special tool, disengage the inboard CV joint housing from the differential side gear.

1. CAUTION: To prevent damage to the axle shaft oil seal, install the special tool before removing the inboard CV joint housing from the axle.
   Install the special tool.

1. Remove the halfshaft assembly from the vehicle.

1. CAUTION: To prevent damage to the axle shaft oil seal, install the Differential Seal Protector before positioning the inboard CV joint housing in the axle.
   CAUTION: Always install the halfshaft with a new retainer circlip and a new rear axle wheel hub retainer.
   CAUTION: Never use power tools to tighten the rear axle wheel hub retainer.
   To install, reverse the removal procedure.