GM Full-Size Trucks 1970-1979 Repair Guide

Steering Column

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See Figure 1



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Fig. Fig. 1: View of the steering column

To perform service procedures on the steering column upper end components, it is not necessary to remove the column from the vehicle.

The steering wheel, horn components, directional signal switch, and ignition lock cylinder may be removed with the column remaining in the vehicle as described earlier in this section.


WARNING
The outer most jacket shift tube, steering shaft and instrument panel mounting bracket are designed as energy absorbing units. Because of the design of these components, it is absolutely necessary to handle the column with care when performing any service operation. Avoid hammering, jarring, dropping or leaning on any portion of the column. When reassembling the column components, use only the specified screws, nuts and bolts and tighten to specified torque. Care should be exercised in using over-length screws or bolts as they may prevent a portion of the column from compressing under impact.

INSPECTION



To determine if the energy absorbing steering column components are functioning as designed, or if repairs are required, a close inspection should be made. Inspection is called for in all cases where damage is evident or whenever the vehicle is being repaired due to a front end collision. Whenever a force has been exerted on the steering wheel or steering column, or its components, inspection should also be made. If damage is evident, the affected parts must be replaced.

The inspection procedure for the various steering column components on all C/K Series Trucks is as follows:

Column Support Bracket

Damage in this area will be indicated by separation of the mounting capsules from the bracket. The bracket will have moved forward toward the engine compartment and will usually result in collapsing of the jacket section of the steering column.

Column Jacket

Inspect jacket section of column for looseness, and/or bends.

Shifter Shaft

Separation of the shifter shaft sections will be internal and cannot be visually identified. Hold lower end of the shifter shaft and move shift lever on column through its ranges and up and down. If there is little or no movement of the shifter shaft, the plastic joints are sheared.

Steering Shaft

If the steering shaft plastic pins have been sheared, the shaft will rattle when struck lightly from the side and some lash may be felt when rotating the steering wheel while holding the rag joint. It should be noted that if the steering shaft pins are sheared due to minor collision the vehicle can be safely steered; however, steering shaft replacement is recommended.

Because of the differences in the steering column types, be sure to refer to the set of instructions below which apply to the column being serviced.

REMOVAL



Front of dash mounting plates must be loosened whenever the steering column is to be lowered from the instrument panel.

  1. Disconnect the battery ground cable.
  2.  
  3. Remove the steering wheel.
  4.  
  5. Remove the nuts and washers securing the flanged end of the steering shaft to the flexible coupling.
  6.  
  7. Disconnect the transmission control linkage from the column shift tube levers.
  8.  
  9. Disconnect the steering column harness at the connector. Disconnect the neutral start switch and back-up lamp switch connectors if so equipped.
  10.  
  11. Remove the floor pan trim cover screws and remove the cover.
  12.  
  13. Remove the transmission indicator cable, if so equipped.
  14.  
  15. Remove the screws securing the two halves of the floor pan cover, then remove the screws securing the halves and seal to the floor pan and remove the covers.
  16.  
  17. Move the front seat as far back as possible to provide maximum clearance.
  18.  
  19. Remove the two column bracket-to-instrument panel nuts and carefully remove from vehicle. Additional help should be obtained to guide the lower shift levers through the firewall opening.
  20.  

DISASSEMBLY



Standard Column

See Figures 2, 3, 4 and 5



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Fig. Fig. 2: Install the steering column in the vise



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Fig. Fig. 3: Remove the turn signal housing



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Fig. Fig. 4: View of the turn signal housing assembly



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Fig. Fig. 5: Remove the ignition switch actuator sector

  1. Remove the four dash panel bracket-to-column screws and lay the bracket in a safe place to prevent damage to the mounting capsules.
  2.  
  3. Place the column in a vise using both weld nuts of either Set A or B or shown in the accompanying figure. The vise jaws must clamp onto the sides of the weld nuts indicated by arrows shown on Set B.
  4.  


WARNING
Do not place the column in a vise by clamping onto one weld nut of both sets A and B or by clamping onto the sides not indicated by arrows, since damage to the column could result.

  1. Remove the turn signal switch, lock cylinder, and ignition switch as outlined previously in this section.
  2.  
  3. For column shift models, drive out the upper shift lever pivot pin and remove the shift lever.
  4.  
  5. Remove the upper bearing thrust washer. Remove the four screws attaching the turn signal and ignition lock housing to the jacket and remove the housing assembly.
  6.  
  7. Remove the thrust cap from the lower side of the housing.
  8.  
  9. Lift the ignition switch actuating rod and rack assembly, the rack preload spring and the shaft lock bolt and spring assembly out of the housing.
  10.  
  11. Remove the shift lever detent plate (shift gate).
  12.  
  13. Remove the ignition switch actuator sector through the lock cylinder hole by pushing firmly on the block tooth of the sector with a blunt punch or screwdriver.
  14.  
  15. Remove the gearshift lever housing and shroud from the jacket assembly (transmission control lock tube housing and shroud on floor shift models).
  16.  
  17. Remove the shift lever spring from the gearshift lever housing (lock tube spring on floor shift models).
  18.  
  19. Pull the steering shaft from lower end of the jacket assembly.
  20.  
  21. Remove the two screws holding the back-up switch or neutral safety switch to the column and remove the switch.
  22.  
  23. Remove the lower bearing retainer clip.
  24.  
  25. For automatic and floorshift columns, remove the lower bearing retainer, bearing adapter assembly, shift tube thrust spring and washer. The lower bearing may be removed from the adapter by light pressure on the bearing outer race. Slide out the shift tube assembly.
  26.  

For manual transmissions and column shift, remove the lower bearing adapter, bearing and the first reverse shift lever. The lower bearing may be removed from the adapter by light pressure on the bearing outer race. Remove the three screws from bearing at the lower end and slide out the shift tube assembly. Remove the gearshift housing lower bearing from the upper end of the mast jacket.

Tilt Columns

See Figures 6, 7, 8 and 9



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Fig. Fig. 6: Remove the tilt lever spring retainer



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Fig. Fig. 7: Remove the bearing housing pivot pins



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Fig. Fig. 8: Remove the shift tube



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Fig. Fig. 9: Remove the sector drive shaft

Steps 3-14 may be performed with the steering column in the vehicle.

  1. Remove the four screws retaining the dash mounting bracket to the column and set the bracket aside to protect the breakaway capsules.
  2.  
  3. Mount the column in a vise using both weld nuts of either Set A or B. The vise jaws must clamp onto the sides of the weld nuts indicated by arrows shown on Set B.
  4.  


WARNING
Do not place the column in a vise by clamping onto only one weld nut, by clamping onto one weld nut of both Sets A and B or by clamping onto the sides not indicated by arrows, since damage to the column could result.

  1. Remove the directional signal switch, lock cylinder and ignition switch as outlined previously in this section.
  2.  
  3. Remove the tilt release lever. Drive out the shift lever pivot pin and remove the shift lever from the housing.
  4.  
  5. Remove the three turn signal housing screws and remove the housing.
  6.  
  7. Install the tilt release lever and place the column in the full up position. Remove the tilt lever spring retainer using a #3 phillips screwdriver that just fits into the slot opening. Insert the phillips screwdriver in the slot, press in approximately 3 / 16 in. turn approximately 1 / 8 turn counterclockwise until the ears align the the grooves in the housing and remove the retainer, spring and guide.
  8.  
  9. Remove the pot joint to steering shaft clamp bolt and remove the intermediate shaft and pot joint assembly. Push the upper steering shaft in sufficiently to remove the steering shaft upper bearing inner race and seat. Pry off the lower bearing retainer clip and remove the bearing reinforcement, bearing and bearing adapter assembly from the lower end of the mast jacket.
  10.  
  11. Remove the upper bearing housing pivot pins using Tool J-21854-1.
  12.  
  13. Install the tilt release lever and disengauge the lock shoes. Remove the bearing housing by pulling upward to extend the rack full down, and then moving the housing to the left to disengauge the ignition switch rack from the actuator rod.
  14.  
  15. Remove the steering shaft assembly from the upper end of the column.
  16.  
  17. Disassemble the steering shaft by removing the centering spheres and the anti-lash spring.
  18.  
  19. Remove the transmission indicator wire, if so equipped.
  20.  
  21. Remove the four steering shaft bearing housing support to gearshift housing screws and remove the bearing housing support. Remove the ignition switch actuator rod.
  22.  
  23. Remove the shift tube retaining rings with a screwdriver and then remove the thrust washer.
  24.  
  25. Install Tool J-23072 into the lock plate, making sure that the tool screws have good thread engaugement in the lock plate, then turning the center screw clockwise, force the shift tube from the housing. Remove the shift tube (transmission control lock tube on floor shift models) from the lower end of the mast jacket. Remove Tool J-23072.
  26.  


WARNING
When removing the shift tube, be sure to guide the lower end through the slotted opening in the mast jacket. If the tube is allowed to interfere with the jacket in any way, damage to the tube and jacket could result.

  1. Remove the bearing housing support lock plate by sliding it out of the jacket notches, tipping it down toward the housing hub at the 12 o'clock position and sliding it under the jacket opening. Remove the wave washer.
  2.  
  3. Remove the shift lever housing from the mast jacket (transmission control lock tube housing on floor shift models). Remove the shift lever spring by winding the spring up with pliers and pulling it out. On floor shift models, remove the spring plunger.
  4.  
  5. Disassemble the bearing housing as follows:
    1. Remove the tilt lever opening shield.
    2.  
    3. Remove the lock bolt spring by removing the retaining screw and moving the spring clockwise to remove it from the bolt.
    4.  
    5. Remove the snapring from the sector driveshaft. With a small punch, lightly tap the driveshaft from the sector. Remove the driveshaft, sector and lock bolt. Remove the rack and rack spring.
    6.  
    7. Remove the tilt release lever pin with a punch and hammer. Remove the lever and release lever spring. To relieve the load on the release lever, hold the shoes inward and wedge a block between the top of the shoes (over slots) and bearing housing.
    8.  
    9. Remove the lock shoe retaining pin with a punch and hammer. Remove the lock shoes and lock shoe springs. With the tilt lever opening on the left side and shoes facing up, the four slot shoe is on the left.
    10.  
    11. Remove the bearings from the bearing housing only if they are to be replaced. Remove the separator and balls from the bearings. Place the housing on work bench and with a pointed punch against the back surface of the race, carefully hammer the race out of the housing until a bearing puller an be used. Repeat for the other race.
    12.  

  6.  

ASSEMBLY



Standard Columns

See Figures 10, 11, 12 and 13



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Fig. Fig. 10: Install the gearshift housing lower bearing



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Fig. Fig. 11: Adjusting the lower bearing. Procedure using shims shown on right



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Fig. Fig. 12: Exploded view of a standard steering column - vehicle equipped with column shift



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Fig. Fig. 13: Exploded view of a standard steering column - vehicle equipped with floor shift

Apply a thin coat of lithium soap grease to all friction surfaces.

  1. Install the sector into the turn signal and lock cylinder housing. Install the sector in the lock cylinder hole over the sector shaft with the tang end to the outside of the hole. Press the sector over the shaft with a blunt tool.
  2.  
  3. Install the shift lever detent plate onto the housing.
  4.  
  5. Insert the rack preload spring into the housing from the bottom side. The long section should be toward the handwheel and hook onto the edge of the housing.
  6.  
  7. Assemble the locking bolt onto the crossover arm on the rack and insert the rack and lock bolt assembly into the housing from the bottom with the teeth up (toward handwheel) and toward the centerline of the column. Align the 1st tooth on the sector with the 1st tooth on the rack; if aligned properly, the block teeth will line up when the rack assembly is pushed all the way in.
  8.  
  9. Install the thrust cup on the bottom hub of the housing.
  10.  
  11. Install the gearshift housing lower bearing. Insert the bearing from the very end of the jacket. Aligning the indentations in the bearing with the projections on the jacket. If the bearing is not installed correctly, it will not rest on all of the stops provided.
  12.  
  13. Install the shift lever spring into the gearshift lever (or lock tube) housing. Install the housing and shroud assemblies onto the upper end of the mast jacket. Rotate the housing to be sure it is seated in the bearing.
  14.  
  15. With the shift lever housing in place, install the turn signal and lock cylinder housing onto the jacket. The gearshift housing should be in P position and the rack pulled downward. Be sure the turn signal housing is seated on the jacket and drive the four screws.
  16.  
  17. Press the lower bearing into the adapter assembly.
  18.  
  19. Insert the shift tube assembly into the lower end of the jacket and rotate until the upper shift tube key slides into the housing keyway.
  20.  
  21. For automatic and floor shift columns, assemble the spring and lower bearing and adapter assembly into the bottom of the jacket. Holding the adapter in place, install the lower bearing reinforcement and retainer clip. Be sure the clip snaps into the jacket and reinforcement slots.
  22.  
  23. For manual transmission and column shift, loosely attach the three screws in the jacket and shift tube bearing. Assemble the 1st/Reverse lever and lower bearing and adapter assembly into the bottom of the jacket. Holding the adapter in place, install the bearing reinforcement and retaining clip. Be sure the retaining clip snaps into the jacket and reinforcement slots.
  24.  
  25. Install the neutral safety or back-up switch as outlined in Suspension & Steering of this guide.
  26.  
  27. Slide the steering shaft into the column and install the upper bearing thrust washer.
  28.  
  29. Install the turn signal switch, lock cylinder assembly and ignition switch as previously outlined in this section.
  30.  
  31. Install the shift lever and shift lever pivot pin.
  32.  
  33. Remove the column from the vise.
  34.  
  35. Install the dash bracket to the column; torque the screws to specifications.
  36.  

Tilt Columns

See Figures 14, 15, 16 and 17



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Fig. Fig. 14: Install the lockbolt and rack assemblies



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Fig. Fig. 15: Installing the shift tube



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Fig. Fig. 16: Exploded view of a tilt steering column - vehicle equipped with column shift



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Fig. Fig. 17: Exploded view of a tilt steering column - vehicle equipped with floor shift

Apply a thin coat of lithium grease to all friction surfaces.

  1. If the bearing housing was disassembled, repeat the following steps:
    1. Press the bearings into the housing, if removed, using a suitable size socket. Be careful not to damage the housing or bearing during installation.
    2.  
    3. Install the lock shoe springs, lock shoes and shoe pin in the housing. Use an approximate 0.180 in. rod to line up the shoes for pin installation.
    4.  
    5. Install the shoe release lever, spring and pin. To relieve the load on the release lever, hold the shoes inward and wedge a block between the top of the shoes (over slots) and bearing housing.
    6.  
    7. Install the sector driveshaft into the housing. Lightly tap the sector onto the shaft far enough to install the snapring. Install the snapring.
    8.  
    9. Install the lock bolt and engauge it with the sector cam surface. Then install the rack and spring. The block tooth on the rack should engauge the block tooth on the sector. Install the external tilt release lever.
    10.  
    11. Install the lock bolt spring and retaining screw. Tighten the screw to 35 inch lbs. (4 Nm).
    12.  

  2.  
  3. Install the shift lever spring into the housing by winding it up with pliers and pushing it into the housing. On floor shift models, install the plunger, slide the gearshift lever housing onto the mast jacket.
  4.  
  5. Install the bearing support lock plate wave washer.
  6.  
  7. Install the bearing support lock plate. Work it into the notches in the jacket by tipping it toward the housing hub at the 12 o'clock position and sliding it under the jacket opening. Slide the lock plate into the notches in the jacket.
  8.  
  9. Carefully install the shift tube into the lower end of the mast jacket. Align keyway in the tube with the key in the shift lever housing. Install the wobble plate end of Tool J-23073 into the upper end of the shift tube far enough to reach the enlarged portion of the tube. Then install the adapter over the end of the tool, seating it against the lock plate. Place the nut on the threaded end of the tool and pull the shift tube into the housing. Remove Tool J-23073.
  10.  


WARNING
Do not push or tap on the end of the shift tube. Be sure that the shift tube lever is aligned with the slotted opening at the lower end of the mast jacket or damage to the shift tube and mast jacket could result.

  1. Install the bearing support thrust washer and retaining ring by pulling the shift lever housing up far enough to compress the wave washer.
  2.  
  3. Install the bearing support by aligning the V in the support with the V in the jacket. Insert the screws through the support and into the lock plate and tighten to 60 inch lbs. (6.7 Nm).
  4.  
  5. Align the lower bearing adapter with the notches in the jacket and push the adapter into the lower end of the mast jacket. Install lower bearing, bearing reinforcement and retaining clip, being sure that the clip is aligned with the slots in the reinforcement, jacket and adapter.
  6.  
  7. Install the centering spheres and anti-lash spring in the upper shaft. Install the lower shaft from the same side of the spheres that the spring ends protrude.
  8.  
  9. Install the steering shaft assembly into the shift tube from the upper end. Carefully guide the shaft through the shift tube and bearing.
  10.  
  11. Install the ignition switch actuator rod through the shift lever housing and insert in the slot in the bearing support. Extend the rack downward from the bearing housing.
  12.  
  13. Assemble the bearing housing over the steering shaft and engauge the rack over the end of the actuator rod.
  14.  
  15. With the external release lever installed, hold the lock shoes in the disengauged position and assemble the bearing housing over the steering shaft until the pivot pin holes line up.
  16.  
  17. Install the pivot pins.
  18.  
  19. Place the bearing housing in the full up position and install the tilt lever spring guide, spring and spring retainer. With a suitable screwdriver, push the retainer in and turn clockwise to engauge in the housing.
  20.  
  21. Install the upper bearing inner race and race seat.
  22.  
  23. Install the tilt lever opening shield.
  24.  
  25. Remove the tilt release lever, install the turn signal housing and tighten the three retaining screws to 45 inch lbs. (5 Nm).
  26.  
  27. Install the tilt release lever and shift lever. Drive the shift lever pin in.
  28.  
  29. Install the lock cylinder, turn signal switch and ignition switch as outlined previously in this section.
  30.  
  31. Align the groove across the upper end of the pot joint with the flat on the steering shaft. Assemble the intermediate shaft assembly to the upper shaft. Install the clamp and bolt and torque the nut to specifications.
  32.  


WARNING
The clamp bolt must pass through the shaft undercut, or damage may occur to the components.

  1. Install the neutral safety switch or back-up switch.
  2.  
  3. Install the four dash panel bracket to column screws and tighten to specifications.
  4.  

Be sure that the slotted openings in the bracket (for the mounting capsules) face the upper end of the steering column.

INSTALLATION



Mandatory Preliminary Instructions
  1. Assemble the lower dash cover and upper dash cover to the seal with fasteners that are part of the seal.
  2.  
  3. Attach bracket to jacket and tighten the four bolts to the specified torque.
  4.  

Mandatory Installation Sequence
  1. Position the column in body and position flange to rag joint and install lock washers and nuts (May be tightened to specified torque at this time). Coupling on manual steering must be installed prior to column installation.
  2.  
  3. Loosely assemble (2) capsules nuts at the instrument panel bracket.
  4.  
  5. Position lower clamp and tighten attaching nuts to specified torque.
  6.  
  7. Tighten two nuts at capsules to specified torque.
  8.  
  9. Install seal and covers to dash.
  10.  
  11. Install attaching screws and tighten to specified torque.
  12.  
  13. Tighten two nuts at capsules to specified torque if not already done.
  14.  
  15. Remove plastic spacers from flexible coupling pins.
  16.  
  17. Install transmission indicator cable on column automatics.
  18.  
  19. Install the instrument panel trim cover.
  20.  
  21. Connect the transmission control linkage at the shift tube levers.
  22.  
  23. Install the steering wheel as outlined previously in this section.
  24.  
  25. Connect the battery ground cable.
  26.  

Mandatory System Requirements
  1. Pot joint operating angle must be 1 1 / 2 °, plus or minus 4°.
  2.  
  3. Flexible coupling must not be distorted greater than plus or minus 0.06 in. due to pot joint bottoming, in either direction.
  4.  

 
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