GM Full-Size Trucks 1988-1998 Repair Information

Leaf Spring

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REMOVAL & INSTALLATION



R/V Series

See Figures 1 and 2

  1. Raise the vehicle and support it so that there is no tension on the leaf spring assembly.
  2.  



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Fig. Fig. 1: Exploded view of a typical rear suspension system-R/V Series 30/3500 shown, others similar



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Fig. Fig. 2: Rear spring U-bolt tightening sequence-R/V Series

  1. Remove the stabilizer bar.
  2.  
  3. Loosen the spring-to-shackle retaining bolts. (Do not remove these bolts).
  4.  
  5. Remove the bolts which attach the shackle to the spring hanger.
  6.  
  7. Remove the nut and bolt which attach the spring to the front hanger.
  8.  
  9. Remove the U-bolt nuts.
  10.  
  11. Remove the stabilizer bar anchor plate, spacers, and shims. Take note of their positions.
  12.  
  13. If so equipped, remove the auxiliary spring.
  14.  
  15. Pull the spring from the vehicle.
  16.  
  17. Inspect the spring and replace any damaged components.
  18.  

If the spring bushings are defective, use the following procedures for removal & installation.3/4ton and 1 ton trucks use bushings that are staked in place. The stakes must first be straightened. When a new bushing is installed stake it in 3 equally spaced locations. Using a press or vise, remove the bushing and install the new one.

To install:
  1. Place the spring assembly onto the axle housing. Position the front and rear of the spring at the hangers. Raise the axle with a floor jack as necessary to make the alignments. Install the front and rear hanger bolts loosely.
  2.  
  3. Install the spacers, shims, auxiliary spring and anchor plate or spring plate.
  4.  
  5. Install the U-bolts, washers and nuts.
  6.  
  7. Tighten the nuts, in a diagonal sequence, to 18 ft. lbs. (24 Nm). When the spring is evenly seated, Tighten the 10/15 and 20/25 Series nuts to 125 ft. lbs. (169 Nm). Tighten the 30/35 Series nuts to 147 ft. lbs. (200 Nm). Use the same diagonal sequence.
  8.  
  9. Make sure that the hanger and shackle bolts are properly installed. The front hanger bolt head is outboard as is the rear spring-to-shackle bolt head. The shackle-to-hanger bolt head faces inboard. When all the bolts, washers and nuts are installed, tighten them to 92 ft. lbs. (124 Nm) if you are torquing on the nut; 110 ft. lbs. (149 Nm) if your are torquing on the bolt head.
  10.  
  11. Install the stabilizer bar.
  12.  

C/K Series

See Figures 3 through 8

  1. Raise the vehicle and support it so that there is no tension on the leaf spring assembly.
  2.  



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Fig. Fig. 3: Rear leaf spring mounting-1991-98 C/K Series, others similar



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Fig. Fig. 4: Installing the rear leaf springs-1988-90 C/K Series



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Fig. Fig. 5: Installing the rear leaf springs-1991-93 C/K Series



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Fig. Fig. 6: Rear axle ride height adjustment-C/K Series



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Fig. Fig. 7: Rear spring U-bolt tightening sequence-C/K Series

  1. Remove the U-bolt nuts, plates, and spacer(s).
  2.  
  3. Remove the anchor plate.
  4.  
  5. Loosen the spring-to-shackle retaining bolts. (Do not remove these bolts).
  6.  
  7. Remove the bolts which attach the shackle to the rear bracket.
  8.  
  9. Remove the bolt which attaches the spring to the front bracket.
  10.  
  11. Pull the spring from the vehicle.
  12.  
  13. Inspect the spring and replace any damaged components.
  14.  

To install:

If the spring bushings are defective, use the following procedures for replacement. On bushings that are staked in place, the stakes must first be straightened. Using a press or vise, remove the bushing and install the new one. When a new, previously staked bushing is installed, stake it in 3 equally spaced locations.

  1. Place the spring assembly onto the axle housing. Position the front and rear of the spring at the brackets. Raise the axle with a floor jack as necessary to make the alignments. Install the front and rear brackets bolts loosely.
  2.  
  3. Install the spacers and spring plate.
  4.  
  5. Install the NEW U-bolts, washers and nuts.
  6.  
  7. Install the anchor plate.
  8.  
  9. Tighten the U-bolt nuts, in a diagonal sequence, to 17 ft. lbs. (23 Nm). When the spring is evenly seated, tighten the nuts as follows:

    15/25 Series: 81 ft. lbs. (110 Nm)
     
    35 Series without dual wheels or 8-7.4L engine: 81 ft. lbs. (110 Nm)
     
    35 Series with dual wheels: 110 ft. lbs. (148 Nm)
     
    35 Series with 8-7.4L engine, without dual wheels: 110 ft. lbs. (148 Nm)
     
    1988-95 C3HD Series: 207 ft. lbs. (280 Nm)
     
    1996-98 C3HD Series: 187 ft. lbs. (253 Nm)
     

  10.  
  11. Make sure that the hanger and shackle bolts are properly installed. All bolt heads should be inboard. Don't tighten them yet.
  12.  
  13. Using the floor jack, raise the axle until the distance between the bottom of the rebound bumper and its contact point on the axle is 182mm plus or minus 6mm.
  14.  
  15. When the spring is properly positioned, tighten all the hanger and shackle nuts as follows:

    Spring-to-bracket nuts 1988-92 15/25/35 series: 89 ft. lbs. (120 Nm)
     
    Spring-to-bracket nuts 1993-95 15/25/35 series: 92 ft. lbs. (125 Nm)
     
    Spring-to-bracket nuts 1996-98 15/25/35 series: 70 ft. lbs. (95 Nm)
     
    Spring-to-bracket nuts 1988-95 C3HD series: 320 ft. lbs. (435 Nm)
     
    Spring-to-bracket nuts 1996-98 C3HD series: 306 ft. lbs. (415 Nm)
     
    Leaf spring-to-shackle nuts 1988-92 15/25/35 series: 89 ft. lbs. (120 Nm)
     
    Leaf spring-to-shackle nuts 1993-95 15/25/35 series: 81 ft. lbs. (110 Nm)
     
    Leaf spring-to-shackle nuts 1996-98 15/25/35 series: 70 ft. lbs. (95 Nm)
     
    Leaf spring-to-shackle nuts 1988-95 C3HD series: 136 ft. lbs. (185 Nm)
     
    Leaf spring-to-shackle nuts 1996-98 C3HD series: 157 ft. lbs. (213 Nm
     
    Shackle-to-bracket nuts 1988-92 15/25/35 series: 89 ft. lbs. (120 Nm)
     
    Shackle-to-bracket nuts 1993-95 15/25/35 series: 81 ft. lbs. (110 Nm)
     
    Shackle-to-bracket nuts 1996-98 15/25/35 series: 70 ft. lbs. (95 Nm)
     
    Shackle-to-bracket nuts C3HD series: 136 ft. lbs. (185 Nm)
     
    Shackle-to-bracket nuts1988-95 C3HD series: 136 ft. lbs. (185 Nm)
     
    Shackle-to-bracket nuts1996-98 C3HD series: 157 ft. lbs. (213 Nm)
     

  16.  

 
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