DRIVESHAFT REMOVAL & INSTALLATION
- Raise the vehicle and safely support it on jackstands. Paint a reference line from the rear end of the driveshaft to the companion flange so that they can be reassembled in the same position.
- Disconnect the rear universal joint by removing the U-bolts or retaining straps.
- To prevent the loss of the needle bearings, tape the bearing caps to the trunnion.
- Remove the driveshaft from the transmission by sliding it rearward.
Do not be alarmed by oil leakage at the transmission output shaft. This oil is there to lubricate the splines of the front yoke.
- Check the yoke seal in the transmission case extension and replace it if necessary.
- Position the driveshaft and insert the front yoke into the transmission so that the splines mesh with the splines of the transmission shaft.
- Using the reference marks made during removal, align the driveshaft with the companion flange and secure it with the U-bolts or retaining straps.
- Remove the driveshaft as explained above and remove the snaprings from the ends of the bearing cup.
- After removing the snaprings, place the driveshaft on the floor and place a large diameter socket under one of the bearing cups. Using a hammer and a drift, tap on the bearing opposite this one. This will push the trunnion through the yoke enough to force the bearing cup out of the yoke and into the socket. Repeat this procedure for the outer bearing cups. If the hammer fails to loosen the cups, a press may be necessary.
A Saginaw design driveshaft secures its U-joints in a different manner than the conventional snaprings of the Dana and Cleveland designs.
Nylon material is injected through a small hole in the yoke and flows along a circular groove between the U-joint and the yoke, creating a synthetic snapring. Disassembly of this Saginaw type U-joint requires the joint to be pressed from the yoke. If a press is not available, it may be carefully hammered out using the same procedure (step two) as the Cleveland design although it may require more force to break the nylon ring. Either method, press or hammer, will damage the bearing cups and destroy the nylon rings. Replacement kits include new bearing cups and conventional metal snaprings to replace the original nylon rings.
- Clean the entire U-joint assembly thoroughly with solvent. Inspect for excessive wear in the yoke bores and on the four ends of the trunnion. The needle bearings should not be scored, broken, or loose in their cups. Bearing cups may suffer slight distortion during removal and should be replaced.
- Pack the bearings with chassis lube (lithium base) and completely fill each trunnion end with the same lubricant.
- Place new dust seals on the trunnions with the cavity of the seal toward the end of the trunnion. Care must be taken to avoid distortion of the seal. A suitably sized socket and a vise can be used to press on the seal.
- Insert one bearing cup about a quarter of the way into the yoke and place the trunnion into the yoke and bearing cup. Install another bearing cup and press both cups in and install the snaprings. Snaprings on the Dana and Cleveland shafts must go on the outside of the yoke while the Saginaw shaft requires that the ring go on the inside of the yoke. The gap in the Saginaw ring must face in toward the yoke. Once installed, the trunnion must move freely in the yoke.
The Saginaw shaft uses two different size bearing cups at the differential end. The larger cups (the ones with the groove) fit into the driveshaft yoke.