GM Cutlass RWD 1970-1987 Repair Guide

Driveshaft and U-Joints

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REMOVAL & INSTALLATION



See Figures 1 and 2

  1. Disconnect the negative battery cable.
  2.  
  3. Raise the vehicle and support it safely with jackstands.
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  5. Matchmark the relationship of the driveshaft to the differential flange so that they can be reassembled in the same position.
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  7. Disconnect the rear U-joint by removing the U-bolts or retaining straps.
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  9. To prevent the loss of the needle bearings, tape the bearing caps in place. If you are replacing the U-joint, this is not necessary.
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  11. Remove the driveshaft from the transmission by sliding it rearward. There will be some oil leakage from the rear of the transmission. It can be contained by placing a small plastic bag over the rear of the transmission and holding it in place with a rubber band.
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Fig. Fig. 1: Common driveshaft and U-joint assembly



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Fig. Fig. 2: U-joint locking methods

  1. To install the driveshaft, first inspect the outer diameter of the slip yoke to make sure it is not burred, or the transmission seal may be damaged. Apply automatic transmission fluid to all splined driveshaft yokes and then insert the driveshaft into the transmission. Don't force the shaft in. If you seem to be having trouble getting it to slip in, check alignment of the splines. If you're replacing the shaft, check for number and type of splines to make sure they are identical to the shaft you removed.
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  3. Before making the rear shaft connection, check the mating surfaces of the shaft and flange for nicks and burrs which could prevent proper seating of the shaft to the flange. Then, using the reference marks made earlier, align the driveshaft with the differential flange and secure it with the U-bolts or retaining straps. Make sure the bearings are aligned in the pinion flange yoke before installing bolts or bolts and straps. Torque bolt straps to 16 ft. lbs. (22 Nm).
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U-JOINT REPLACEMENT



See Figures 3, 4, 5 and 6

NEVER clamp a driveshaft in a vise, as the tube is easily dented. Always clamp on one of the yokes, and support the shaft horizontally.

  1. Remove the driveshaft.
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  3. Remove the snaprings from the end of the bearing cup.
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  5. 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 other cups. If a hammer doesn't loosen the cups, they will have to be pressed out.
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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 thus creating a synthetic snapring. Disassembly of this Saginaw-type U-joint requires that the joint be recessed from the yoke. If a press is not available, it may be carefully hammered out using the same procedure (Step 2) as the Dana 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 type rings.

  1. Using solvent, thoroughly clean the entire U-joint assembly. 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. Bearings cups may suffer slight distortion during removal and should be replaced.
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Fig. Fig. 3: Bearing removal



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Fig. Fig. 4: Partially inserted bearing cap

  1. Pack the bearings with chassis lube (lithium base) and completely fill each trunnion end with the same lubricant.
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  3. Place new dust seals on trunnions with cavity of seal toward end of trunnion. Care must be taken to avoid distortion of the seat. A suitable size socket and a vise can be used to press on the seal.
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  5. Insert one bearing cup about 1 / 4 in. (6mm) of the way into the yoke and place the trunnion into yoke and bearing cup. Install another bearing cup and press both cups in and install the snaprings. The snaprings on the Dana and Cleveland shaft must go on the outside of the yoke while the Saginaw shaft requires that the rings 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.
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Fig. Fig. 5: Plastic retainer U-joint repair kit components



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Fig. Fig. 6: Installing the retaining ring

The Saginaw shaft uses two different size bearing cups (the one with the groove fits into the driveshaft yoke).

 
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