The driveshaft is the means by which the power from the engine and transmission (in the front of the car) is transferred to the differential and rear axles, and finally to the rear wheels.
The driveshaft assembly incorporates two universal joints (one at each end) and a slip yoke at the front, which fits into the back of the transmission.
All driveshafts are balanced when installed in a car. It is therefore important to cover the driveshaft and universal joint assembly completely before applying undercoating to the chassis. A layer of undercoat on one side of a driveshaft will cause imbalance and vibration.
REMOVAL & INSTALLATION
See Figures 1 through 5
- Mark the relationship of the rear driveshaft yoke to the drive pinion flange of the axle. If the original yellow alignment marks are visible, there is no need for new marks. The purpose of this marking is to replace the assembly in its original position, maintaining proper balance.
- Remove the bolts which hold the rear universal joint to the pinion flange. Wrap tape around the loose bearing caps in order to prevent them from falling off the spider.
- Pull the driveshaft toward the rear until the slip yoke clears the transmission housing and the seal. Plug the hole at the rear of the transmission housing or place a container under the opening to catch any fluid which might leak.
- Carefully inspect the rubber seal on the output shaft and the seal in end of the transmission extension housing. Replace them if they are damaged.
- Examine the lugs on the axle pinion flange and replace the flange if the lugs are shaved or distorted.
- Coat the yoke spline with special-purpose lubricant. (The Ford part number for this lubricant is B8A-19589-A.)
- Remove the plug inserted into the rear of the transmission housing.
- Insert the yoke into the transmission housing and onto the transmission output shaft. Use care to make sure that the yoke assembly does not bottom on the output shaft with excessive force.
- Locate the marks made on the rear driveshaft yoke and the pinion flange prior to removal of the driveshaft assembly. Install the driveshaft assembly with the marks properly aligned.
- Install the U-bolts and nuts that attach the universal joint to the pinion flange. Torque the U-bolt nuts to 8-15 ft. lbs.
UNIVERSAL JOINT REPLACEMENT
See Figure 6
- Position the driveshaft assembly in a vise.
- Remove the snaprings which retain the bearings in the slip yoke (front only) and in the driveshaft (front and rear).
- Using a large punch or an arbor press, drive one of the bearings in toward the center of the universal joint, forcing the opposite bearing out.
- As each bearing is pressed or punched far enough out of the universal joint assembly, grip it with a pair of pliers, and pull it from the driveshaft yoke. Drive or press the spider in the opposite direction to make the opposite bearing accessible, and pull it free. Remove all bearings from both universal joints.
- After removing the bearings, lift the spider from the yoke.
- Thoroughly clean all dirt and foreign matter from the yoke area on both ends of the driveshaft.
When installing new bearings within the yokes, it is advisable to use an arbor press. However, if this tool is not available, the bearings should be driven into position with extreme care, as a heavy jolt on the needle bearings can easily damage or misalign them.
- Start a new bearing into the yoke at the rear of the driveshaft.
- Position a new spider in the rear yoke and press (or drive) the new bearing 1 / 4 inch below the outer surface of the yoke.
- With the bearing in position, install a new snapring.
- Start a new bearing into the opposite side of the yoke.
- Press (or drive) the bearing until the opposite bearing, which you have just installed, contacts the inner surface of the snapring.
- Install a new snapring on the second bearing. It may be necessary to grind the surface of this second snapring to ease installation.
- Reposition the driveshaft in the vise, to work on the front universal joint.
- Install the new bearings, new spider, and new snaprings in the same manner as for the rear universal joint.
- Position the slip yoke on the spider. Install new bearings, nylon thrust bearings (1967-1971 cars only), and snaprings.
- Check both reassembled joints for freedom of movement. If misalignment of any part is causing a bind, a sharp rap on the side of the yoke with a brass hammer should seat the bearing needles, and provide freedom of movement. Care should be used to firmly support the shaft end during this operation, as well as to prevent blows to the bearings themselves. Under no circumstances should a driveshaft be installed if there is any bind in the universal joints.