How to replace the worn out oil seal of the differential

There are thin sleeves to put on the crankshaft to enlarge the shaft to cover the worn out area on the crankshaft ,so the seal will keep the oil in , These are available at a good auto parts store I believe we called them speedy sleeves. Older fords had problems with axels leaking differential oil on to brake shoes. Very common problem with small block chev V8's to leak oil at front cover of the motor. Just slide the sleeve on, and install the seal

First replace the seal and case cover gasket, then top up diff oil, test to see if noisy is eliminated , because since the oil is leaking it might be running dry.

The clunking noise is a sign that the rear axle diffential gear oil needs to be changed. Put a catch pan underneath it, and remove all the bolts from the differential cover. Drain the old oil, and spray brake cleaner into the area to flush all dirt deposits from the unit. The brake cleaner evaporates and won't leave a residue.

Put a silicone sealant around the cover before remounting. Refill the unit with the gear oil weight specified in your maintenance manual, and also add a tube of limited slip differential paste (available at Autozone). Fill the differential until it begins to overflow from the fill hole.

Concerning the black gunky substance leaking out: there's a good chance that the axle seal is worn and letting the differential gear oil leak out. You should consider replacing those before refilling the differential. It will continue to leak until you do so.

Best regards,
Steve

what about it?

conventional axle or limited slip? Get axle code off door sticker.

SECTION 205-02: Rear Drive Axle/Differential - Ford 8.8-Inch Ring Gear 1998 Explorer/Mountaineer Workshop Manual
IN-VEHICLE REPAIR Rear Wheel Bearing and Axle Shaft Oil Seal -4.0L SOHC and 4.0L EI, Conventional
Special Tool(s) Axle Seal Replacer
T83T-1175-A Axle Wheel Bearing Puller
T83T-1225-A Axle Wheel Bearing Replacer
T83T-1225-B Driver Handle
T80T-4000-W Impact Slide Hammer
T50T-100-A
Removal

1. Remove the axle shaft; refer to Axle Shaft in this section.

Axle Shaft Removal

1. CAUTION: Do not use heat to loosen a seized lug nut. Heat can damage the wheel (1007) and the rear wheel bearings (1225).
   Loosen the lug nuts (1012).
   1. Remove the center cap.
   1. With the weight of the vehicle on the wheels, loosen the lug nuts.

1. Raise and support the vehicle.

1. Remove the wheel and tire assembly.
   1. Remove the lug nuts.
   1. Remove the wheel and tire assembly.

1. 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.

1. Remove the rear disc brake rotors (2C026); refer to Section 206-04 .

1. 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.
   Remove the differential pinion shaft.
   1. Remove the differential pinion shaft lock bolt.
   1. Remove the differential pinion shaft.

1. CAUTION: Do not damage the rubber O-rings in the U-washer grooves.
   Remove the U-washers (4N237).
   1. Push the axle shafts inboard.
   1. Remove the U-washers.

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

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

Installation

1. 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.
   Remove the differential pinion shaft.
   1. Remove the differential pinion shaft lock bolt.
   1. Remove the differential pinion shaft.

1. CAUTION: Do not damage the inner wheel bearing oil seal.
   Install the two axle shafts.

1. 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.

1. 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.

1. Install the rear disc brake rotors; refer to Section 206-04 .

1. Install the axle housing cover and fill the rear axle housing (4010) with 2.4 liters (5.5 pints) of specified lubricant; refer to Axle Housing Cover in this section.

1. 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.

1. Install the tire and wheel assembly.
   1. Position the tire and wheel assembly.
   1. Install the lug nuts and lower the vehicle.
   1. Tighten the lug nuts.
   1. Install the center cap.

1. 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.

Installation

1. Lubricate the new rear wheel bearing.
   1. Use Thermally Stable Rear Axle Lubricant XY-80W90-QL or equivalent meeting Ford specification WSP-M2C197-A.

1. Use Axle Wheel Bearing Replacer with Driver Handle to install the rear wheel bearing.

1. Lubricate the lip of the new axle shaft oil seal.
   • Use Premium Long-Life Grease XG-1-C or equivalent meeting Ford specification ESA-M1C75-B.

1. Use Axle Seal Replacer with Driver Handle to install the axle shaft oil seal.

1. Install the axle shaft; refer to Axle Shaft in this section.

Your car has several different types of oils or fluids (motor oil, transmission oil, power steering fluid/oil, brake fluid, and differential oil - if applicable). . Before you can determine how to fix your problem, you need to determine exactly what you problem is, meaning you need to figure out what fluid is leaking.

Good Luck!

Could be low on differential fluid, leaking from the wheel seal. The Differential gears could also be worn from low on fluid or ears was not lined up and have worn it self out.

Service the rear end, inspect the fluid's condition and measure the any play in the gears in the rear end replace is worn out.

You may buy some time by running 50% to 100% Lucas oil treatment in your rear differential. Good luck and hope your differential is not to badly worn.

Not that difficult, raise and support the rear of the truck and remove the wheels. Might as well replace both sides so you know you have new seals, remove the differential cover and drain the fluid. Once differential is opened and cleaned , remove the axle "C" clip that hold the axle in place and slide the axle out. Once the axle is out remove the wheel seal and clean around the area. This would be a good time to replace the wheel bearing too since you have access to them and there not that expensive. Install the new bearing and seal, note make sure you oiled the bearing and seal before installing it back and take care when installing the axle back in and "C: clip. Use RTV silicon gasket maker to seal the differential cover and wheels back on and lower. If your lazy like i am, you can drain the differential fluid and replace it with a 50/50 mix with gear oil and Lucas engine oil additives. That may stop the leak and get you a few more miles. You gear oil is (ford 75W-140) (Dana 80W-90)and the capacity is 2.6 liters and 3.5 liters if you have the 10.25 Ring gear. Good luck and hope this helps.

Not that difficult, raise and support the rear of the truck and remove the wheels. Might as well replace both sides so you know you have new seals, remove the differential cover and drain the fluid. Once differential is opened and cleaned , remove the axle "C" clip that hold the axle in place and slide the axle out. Once the axle is out remove the wheel seal and clean around the area. This would be a good time to replace the wheel bearing too since you have access to them and there not that expensive. Install the new bearing and seal, note make sure you oiled the bearing and seal before installing it back and take care when installing the axle back in and "C: clip. Use RTV silicon gasket maker to seal the differential cover and wheels back on and lower. If your lazy like i am, you can drain the differential fluid and replace it with a 50/50 mix with gear oil and Lucas engine oil additives. That may stop the leak and get you a few more miles. You gear oil is 75W-90 and the capacity is 2.6 liters and 3.6 liters if you have the 11.50 Ring gear. Good luck and hope this helps. 

There is a vacum switch in the transfercase on the drivers side. you can get to it with a wrench, but it will make you work for it. Part store is like $45.00 GM like $90.00, Same part.
Rear bearing. remove the differental cover and drain fluid. Remove the C Clip that hold the Axle in. Slide the Axle out and inspect to see if you need a new one. High mile axle has a worn grove where the bearings are and changing the bearing alone does nothing. You ight get away with a finding a bearing to match your axle if it's worn. 
Remove the oil seal and then the bearing from the axle tube. 
In-stall in revers, note use lots of lube on the seal and be careful not to nick the seal and bearing. 
Fill differental with oil and run around the block, not hard and re-check the fluid. May want to go with syntetic oil or add lucus. Less maintance of oil changes to differental.
Good luck and hope this help.

Axle Shaft Removal

1. Raise and support the vehicle. For additional information, refer to Section 100-02 .

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

1. Remove the differential housing cover (4033).
   1. Loosen the bolts and drain the lubricant from the rear axle housing (4010).
   1. Remove the bolts.
   1. Remove the differential housing cover.

Remove the rear brake disc (2C026). For additional information, refer to Section 206-04 .

1. CAUTION: Turning the differential case (4204) or an axle shaft (4234) with the differential pinion shaft (4211) removed will cause the differential pinion gears (4215) to fall out of the assembly and damage the components.
   Remove the differential pinion shaft.
   1. Remove the differential pinion shaft lock bolt.
   1. Remove the differential pinion shaft.
2. CAUTION: Do not damage the rubber O-ring in the U-washer groove.
3. Remove the U-washer (4N237).
4. Push the axle shaft inboard.
5. Remove the U-washer.

Reinstall the differential pinion shaft.

1. Install the differential pinion shaft.
2. Install the differential pinion shaft lock bolt finger-tight.
3. CAUTION: Do not damage the wheel bearing oil seal (1177).
   Remove the axle shaft.

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Seal Removal

1. Remove the axle shaft (4334). For additional information, refer to Axle Shaft in this section.

1. CAUTION: Never remove the wheel bearing oil seal (1177) by itself. Always remove the rear wheel bearing (1225) and the inner wheel bearing oil seal at the same time.
   NOTE: If the wheel bearing oil seal is leaking, the axle housing vent may be plugged with foreign material.
   Using the special tools, remove the rear wheel bearing and wheel bearing oil seal together.

Installation

1. Lubricate the new rear wheel bearing.
   • For 4.0L SOHC and 4.0L EI with limited slip rear axles and 5.0L vehicles, use SAE 75W-140 High Performance Rear Axle Lubricant F1TZ-19580-B or equivalent meeting Ford specification WSL-M2C192-A.
   • For 4.0L SOHC and 4.0L EI with conventional rear axles, use SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL or equivalent meeting Ford specification WSP-M2C197-A.

1. Using the special tools, install the rear wheel bearing.

1. Lubricate the lip of the new wheel bearing oil seal.
   • Use Premium Long-Life Grease XG-1-C or equivalent meeting Ford specification ESA-M1C75-B.

1. Using the special tools, install the wheel bearing oil seal.

1. Install the axle shaft. For additional information, refer to Axle Shaft in this section.