Jeep CJ/Scrambler 1971-1986 Repair Guide

U-Joints

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Most Jeep vehicles use a conventional universal joint at both ends of both driveshafts. The CJ-7 and Scrambler with automatic transmission use a double, or constant velocity, joint at the transfer case end of the front driveshaft. Universal joints on 1971 models are held together by snaprings on the outside of the bearing caps; 1972-86 models have C-type retainer rings on the inside of the bearing caps. The constant velocity joint is also assembled with snaprings on the outside.

On 1971 vehicles, three types of front axle U-joints were used; the Bendix type and the Rzeppa type, used on axle model 27, and the more familiar single cross cardan type used on axle model 27AF. All axles after 1972 use the single cross cardan type.

OVERHAUL



See Figures 1, 2, 3, 4, 5, 6 and 7

1971 Models
  1. Remove the snaprings by pinching the ends together with a pair of pliers. If the rings do not readily snap out of the groove, tap the end of the bearing lightly to relieve pressure against the rings.
  2.  
  3. After removing the snaprings, press on the end of one bearing until the opposite bearing is pushed from the yoke arm. Turn the joint over and press the first bearing back out of that arm by pressing on the exposed end of the journal shaft. To drive it out, use a soft drift with a flat face, about 1 / 32 in. (0.8mm) smaller in diameter than the hole in the yoke; otherwise there is danger of damaging the bearing.
  4.  
  5. Repeat the procedure for the other two bearings, then lift out the journal assembly by sliding it to one side.
  6.  
  7. Wash all parts in cleaning solvent and inspect the parts after cleaning. Replace the journal assembly if it is worn extensively. Make sure that the grease channel in each journal trunnion is open.
  8.  
  9. Pack all of the bearing caps 1 / 3 full of grease and install the rollers (bearings).
  10.  
  11. Press one of the cap/bearing assemblies into one of the yoke arms just far enough so that the cap will remain in position.
  12.  
  13. Place the journal in position in the installed cap, with a cap/bearing assembly placed on the opposite end.
  14.  
  15. Position the free cap so that when it is driven from the opposite end it will be inserted into the opening of the yoke. Repeat this operation for the other two bearings.
  16.  
  17. Install the retaining clips. If the U-joint binds when it is assembled, tap the arms of the yoke slightly to relieve any pressure on the bearings at the end of the journal.
  18.  

Bendix Joint

With ordinary shop equipment it is nearly impossible to satisfactorily rebuild this unit. For this reason, the factory no longer supplies parts. After considerable mileage, a joint may pull apart upon removal from the vehicle. This does not mean that the joint is no longer usable. To assemble the axle shaft and universal:

  1. Place the differential half of the shaft in a vise with the ground portion above the jaws.
  2.  
  3. Install the center ball (the one with the drilled hole) in the socket in the shaft, with the hole and groove visible.
  4.  
  5. Drop the center ball pin into the drilled hole in the wheel half of the shaft.
  6.  
  7. Place the wheel half of the shaft on the center ball. Slip the three balls into the races.
  8.  
  9. Turn the center ball until the groove lines up with the race for the remaining ball. Slip the ball into the race and straighten the wheel end of the shaft.
  10.  
  11. Turn the center ball until the pin drops into the hole in the ball.
  12.  
  13. Install the lock pin and center punch both ends to secure it.
  14.  



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Fig. Fig. 1: Bendix front axle U-joint components



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Fig. Fig. 2: Component view of the Bendix joint

Rzeppa Joint

With the joint removed, determine the method of attachment of the axle to the joint. If three bolts are used, use step 1; if there are no screws, skip 1 and proceed to step 2.

  1. Remove the three screws securing the front axle to the joint. Pull the shaft free of the splined inner race. Remove the retaining ring and remove the axle shaft retainer.
  2.  
  3. To remove the axle shaft from the joint, use a wooden pry, and exert force in the direction of the axis of the axle shaft. Use a mallet, if necessary, to exert enough force to drive the retaining ring, installed on the end of the shaft, into its groove in the spline, permitting the joint to be slipped off the shaft.
  4.  
  5. Push down on various points of the inner race and cage until the balls can be removed with the help of a small screwdriver.
  6.  
  7. There are two large rectangular holes in the cage as well as four small holes. Turn the cage so that the two bosses in the spindle shaft will drop onto the rectangular holes and lift out the cage.
  8.  
  9. To remove the inner race, turn it so that one of the bosses will drop into a rectangular hole in its cage and shift the race to one side. Lift it out.
  10.  
  11. Assembly is the reverse of disassembly. Take care to keep all parts as clean as possible.
  12.  



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Fig. Fig. 3: Rzeppa front axle U-joint components



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Fig. Fig. 4: Removing the balls from the Rzeppa joint using a small prybar



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Fig. Fig. 5: Once the balls have been removed from the joint, the cage can be removed

1972-86 Single Cross Cardan Joint
  1. Clamp the yoke, not the tube, in a vise.
  2.  
  3. Remove the bearing cap C-retainers. Tap on the bearing caps to relieve pressure as necessary.
  4.  
  5. Support the yoke on the vise jaws.
  6.  
  7. Tap one bearing cap in until the opposite one comes out.
  8.  
  9. Turn the yoke around and tap the exposed end of the spider to drive the remaining bearing cap out.
  10.  
  11. Clean all parts in solvent and dry. Use all the parts in the repair kit, even if some of the old ones seem usable.
  12.  
  13. Lubricate all needle bearings, bearing caps, and bearing surfaces with chassis grease.
  14.  
  15. Place the seals on the spider.
  16.  
  17. Install one cap and needle bearing assembly partway into the shaft yoke.
  18.  
  19. Install the spider and the opposite bearings and cap.
  20.  
  21. Support the yoke and seat both caps with a hammer.
  22.  
  23. Install the retainer C-clips. Tap the bearing caps as necessary.
  24.  
  25. Install the other two cap and bearing assemblies. Hold them in place with tape until the shaft is reinstalled.
  26.  



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Fig. Fig. 6: Single cross Cardan type U-joint components

Constant Velocity (Double Cardan) Joint
  1. Remove the bearing cap retainer snaprings.
  2.  
  3. Mark all components for reassembly.
  4.  
  5. Use a 5 / 8 in. socket as a bearing cap driver and a 1 1 / 16 in. socket as a bearing cap receiver. Squeeze the assembly in a vise to force out the bearing caps.
  6.  
  7. Repeat the operation of step 3 to remove the bearing caps at the other end of the joint.
  8.  
  9. Clean all parts in solvent and dry.
  10.  

Do not disassemble the socket yoke, centering ball, spring, needle bearings, retainer, and thrust washers. These parts are sold as an assembly only.

  1. Lubricate all bearings and contact surfaces with chassis grease.
  2.  
  3. Install the bearing caps on the transfer case yoke ends of the rear spider. Tape them in place.
  4.  
  5. Assemble the socket yoke and the rear spider.
  6.  
  7. Place the rear spider in the link yoke and install the bearing caps. Press them into place with the 5 / 8 in. socket. Install the snaprings.
  8.  
  9. Install the front spider, bearing caps, and snaprings in the driveshaft yoke.
  10.  
  11. Install the thrust washer and socket spring in the ball socket bearing bore. Install the thrust washer on the ball socket bearing boss on the driveshaft yoke. Align the ball socket bearing boss with the ball socket bearing bore and insert the boss into the bore.
  12.  
  13. Align the front spider with the link yoke and install the bearing caps and snaprings.
  14.  



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Fig. Fig. 7: CV-joint components, Double Cardan type

 
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