Flange Yoke Seal and/or Universal Joint Flange, Rear Axle

Removal

Replacement of flange yoke seal (4676) only involves removal and installation of the pinion nut and rear axle universal joint flange (4851) .

 CAUTION: This operation disturbs the pinion bearing preload, and this preload must be carefully reset when assembling.

1. Raise the vehicle and install safety stands. Refer to Section 00-02. Remove the rear wheels (1007) .

2. Make scribe marks on the driveshaft centering socket yoke (4782) and rear axle universal joint flange to ensure proper position of the driveshaft (4602) during assembly. Disconnect the driveshaft from the rear axle universal joint flange . Remove the driveshaft from the transmission extension housing. Install an oil seal replacer tool in the transmission extension housing to prevent oil leakage.
   
   
   
   

3. Install a Nm (lb-in) torque wrench on the pinion nut. Record the torque required to maintain rotation of the pinion through several revolutions.
   
   
   
   

4. While holding rear axle universal joint flange with Companion Flange Holding Tool T78P-4851-A, remove pinion nut.
   
   
   
   

5. Clean area around the flange yoke seal . Place a drain pan under flange yoke seal or raise front of vehicle higher than rear.

6. Mark rear axle universal joint flange in relation to pinion shaft so rear axle universal joint flange can be installed in same position.
   
   
   
   

7. Remove rear axle universal joint flange using Companion Flange Remover T65L-4851-B.
   
   
   
   

    CAUTION: Do not damage rear axle housing (4010) while removing flange yoke seal .

8. Position screwdriver under flange of flange yoke seal and strike with hammer to wedge screwdriver blade between metal flange of flange yoke seal and rear axle housing .
   
   
   
   

9. Pry up on metal flange of flange yoke seal . Install gripping pliers and strike with hammer until flange yoke seal is removed.
   
   
   
   

Installation

 CAUTION: Installation without proper tool may result in early flange yoke seal failure. If flange yoke seal becomes cocked during installation, remove and replace with new flange yoke seal .

1. Clean the flange yoke seat surface and install flange yoke seal on Pinion Seal Replacer T79P-4676-A. Apply Premium Long-Life Grease XG-1-C or -K or equivalent meeting Ford specification between the rubber seal lips if flange yoke seal is not pregreased.
   
   
   
   

2. Check splines on the pinion shaft to be sure they are free of burrs. If burrs are evident, remove them by using a fine crocus cloth. Working in a rotating motion, wipe the pinion clean.

3. Install flange yoke seal in rear axle housing .
   
   
   
   

   NOTE: Check rear axle universal joint flange for burrs. Remove burrs as necessary.

4. Apply a small amount of Rear Axle Lubricant to rear axle universal joint flange splines.

5. Align mark on rear axle universal joint flange with mark on the pinion shaft. Install rear axle universal joint flange .

6. Install a new pinion nut on pinion shaft (apply a small amount of lubricant on the washer side of nut).

7. Hold the circular rear axle universal joint flange with Companion Flange Holding Tool T78P-4851-A while tightening the nut.
   
   
   
   

8. Rotate pinion occasionally to ensure proper bearing seating. Take frequent pinion bearing torque preload readings while tightening, until the original recorded preload reading is obtained.

9. If the original recorded preload is less than specification, tighten to specification. If the preload is higher than specification, tighten to original reading as recorded.

    CAUTION: The circular rear axle universal joint flange must never be hammered on, or assembled with power tools.

   Under no circumstances should the pinion nut be backed-off to reduce preload. If reduced preload is required, a new differential drive pinion bearing spacer (4662) and pinion nut must be installed.

10. Remove oil seal replacer tool from the transmission extension housing. Install the front end of the driveshaft on the transmission output shaft.

11. Connect the rear end of the driveshaft to the rear axle universal joint flange , aligning the scribe marks on the driveshaft and rear axle universal joint flange . Tighten the four bolts to 95-130 Nm (70-95 lb-ft).

     CAUTION: Overfilling axles may cause seal and axle leakage.

12. Fill axle with lubricant until fluid level is within 6-14mm (0.250-0.562 inch) below bottom of fill hole with the axle in operating position. Add four ounces of Additive Friction Modifier C8AZ-19B564-A or equivalent meeting Ford specification EST-M2C118-A for Traction-Lok axles. Refer to Specifications. Install oil filler plug. Tighten to 20-41 Nm (15-30 lb-ft).

13. Ensure rear axle housing vent (4022) is not plugged with debris.