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 (through 1980) two universal joints-one at each end- and a slip yoke at the front end of the assembly, which fits into the back of the transmission. Beginning with 1981 models, a two piece driveshaft with a center bearing support and universal joint is installed.
All driveshafts are balanced when installed in a car. It is, therefore, imperative that before applying undercoating to the chassis, the driveshaft and universal joint assembly be completely covered to prevent the accidental application of undercoating to their surfaces, and the subsequent loss of balance.
REMOVAL & INSTALLATION
Except 4-WD Vista
- Mark the relationship of the rear driveshaft yoke and the drive pinion flange of the axle. The purpose of this marking is to facilitate installation of the assembly in its exact original position, thereby maintaining proper balance of the driveshaft assembly.
- Remove the four bolts which hold the rear universal joint to the pinion flange. Remove center support bolts if equipped.
- Pull the driveshaft toward the rear of the vehicle 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 out.
- Carefully inspect the rubber seal in the end of the transmission extension housing. Replace it if it is 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 lubricant.
- Remove the plug which you inserted into the rear of the transmission housing.
- Insert the yoke into the transmission housing and onto the transmission output shaft. Make sure that the yoke assembly does not bottom on the output shaft with excessive force.
- Locate the marks which you 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. Secure center support.
- Install the bolts that attach the universal joint to the pinion flange. Torque the bolts to 25-30 ft. lbs. Center support bolts are tightened to 22-29 ft. lbs.
- Raise and support the car on jackstands.
- Drain the transfer case.
- Matchmark the differential companion flange and the driveshaft flange yoke.
- Unbolt the driveshaft from the differential flange.
- Remove the two center bearing attaching nuts.
Make sure you don't confuse the flat washer and the adjusting spacer. Keep them separate for assembly.
- Pull the driveshaft from the transfer case. Be careful to avoid damaging the transfer case oil seal.
- Align the matchmarks and install the driveshaft. Torque the center bearing nuts to 25-30 ft. lb.; the driveshaft-to-differential flange nuts to 20-25 ft. lbs.
Matchmark the rear yoke to shaft and/or the center yoke to yoke for proper installation reference.
- Position the driveshaft assembly in a sturdy vise.
- Remove the snaprings which retain the bearing caps in the slip yoke and the driveshaft.
- Use a large punch or an arbor press and drive one of the bearing caps in toward the center of the universal joint. The joint will be forced through the opposite side of the yoke.
- As the opposite side bearing cap is forced from the yoke, grip it with a pair of pliers and pull it, in a twisting motion, out of the yoke.
- Press the spider cross toward the side you just pushed to force the cap back into the yoke. When the bearing cap starts to clear the yoke, pull it free with a pair of pliers. Repeat the procedure with the other side bearing caps.
- After removing the bearing caps, lift the bearing (spider)cross from the yoke. Thoroughly clean all dirt and foreign matter from the yoke area on both ends of the driveshaft.
When installing new bearing caps within the yokes, it is advisable to use an arbor press. However, if a press is not available, the bearings should be driven into position with extreme care. A heavy jolt on the needle bearing, in the cap, can easily damage or misalign them. A large vise and correct size drivers and spacers can sometimes be used, in place of a punch, to push the bearing caps in or out.
- Start a bearing cap into the yoke bore.
- Position the spider into the yoke and into the bearing cap. Push the cap the rest of the way into the yoke bore until it is about 6mm below the outside surface of the yoke. Install a new snapring.
- Start a bearing cap into the yoke on the opposite side of the one just installed. Carefully press it into the yoke while aligning the spider cross with the bearing center.
- Continue to press the cap in until the opposite side bearing cap contacts the snapring. Install a new snapring on the side just installed. Check the clearance between the bearing cap face and the snapring. If it exceeds 0.025mm, install a thicker snapring. Check the joint for free movement. Complete the installation of the yoke and bearing caps.
- Position the driveshaft and work on the other end if service is required.
- After service is completed, check the assembled joints and yokes for freedom of movement. If misalignment of any part causes it to bind, a sharp rap on the side of the yoke with a brass hammer should seat the needle bearings, and provide the desired freedom of movement. Care should be exercised to firmly support the shaft end during this operation, as well as to prevent blows to the bearing caps themselves. Under no circumstances should a driveshaft be installed in a vehicle if there is any bind in the U-joints. If the binding remains, disassemble the yoke and joint a check the needle bearings for correct vertical alignment.