Suspension - Front Coil Spring (2wd) GMC Suburban I

DESCRIPTION

Independent front suspension consists of upper and lower control arms with steering knuckle mounted between ball joints. (Scheme 1) Upper control arm is mounted directly to frame with pivot bolts. Lower control arm is mounted directly to frame with pivot bolts.

Coil springs are mounted between lower control arm and a formed seat in suspension crossmember. Shock absorbers fit between lower control arm and frame. A stabilizer bar is mounted to frame side rails and connected to lower control arms.

Scheme 1

WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES

Note. See the WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES article in the WHEEL ALIGNMENT section.

FRONT WHEEL BEARINGS

1. Raise and support vehicle. Remove hub dust cap and cotter pin. Tighten spindle nut to 12 ft. lbs. (16 N.m) while turning wheel forward by hand. Back off nut until just loose.
2. Finger-tighten nut until snug. Loosen nut slightly until NEW cotter pin can be installed. DO NOT loosen nut more than 1/2 flat. Install cotter pin and measure hub end play. Hub end play (in and out movement) should be .001-.008" (.03-.20 mm). Install dust cap.

RIDING HEIGHT

Note. See the RIDING HEIGHT ADJUSTMENT article in WHEEL ALIGNMENT.

BALL JOINT CHECKING

Note. Ensure wheel bearings are properly adjusted before checking ball joints. Replace ball joint rubber grease seal if cut or damaged.

Upper & Lower Ball Joints

1. Raise and support vehicle with jackstand under lower control arm, near lower ball joint. Place a dial indicator on spindle hub.
2. Pry tire and wheel assembly between lower control arm and outer race to measure vertical movement. Note dial indicator reading. If reading exceeds .08" (2.0 mm), replace loose ball joint.

Removal

1. Raise and support vehicle. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove dust cap, cotter pin, spindle nut and washer. Carefully remove hub/rotor assembly to avoid damage to spindle threads.
2. Remove outer bearing, inner grease seal and inner bearing. Clean bearings, and inspect bearings and races for damage. If races require removal from hub, drive old races from hub using hammer and Wheel Bearing Race Remover (J-29117 ).

Installation

1. To install, reverse removal procedure. Pack bearings with high-temperature bearing grease. Install NEW grease seal until seal is even with hub surface. Lubricate seal lip and hub cavity with wheel bearing grease.
2. Tighten bolts/nuts to specs. See «TORQUE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) . Adjust wheel bearings. See «FRONT WHEEL BEARINGS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd__front-wheel-bearings) under ADJUSTMENTS. Lower vehicle and check wheel alignment. See the «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(/gmc/suburban/i-1992-1999/remont/wheel-alignment/#wheel-alignment-specifications-procedures) article in the WHEEL ALIGNMENT section.

Raise and support vehicle. Remove wheel and tire assembly. Hold upper stem from turning while removing upper stem retaining nut, retainer and rubber grommet at top of shock absorber. Remove shock absorber-to-lower control arm bolts and nuts. Lower shock absorber from vehicle.

Note. Purging air from non-spiral groove shock is not required, as reservoir has gas-charged cell. Spiral groove shock has air-charged cell and air must be purged.

Inspection

1. On spiral groove shock, purge air from pressure chamber by mounting shock in vise (top end up) and fully extending unit. Reverse position (top end down) and fully collapse unit. Repeat procedure several times.
2. Bench check shock unit by mounting in vise with top end up (top end down on gas-charged shocks). DO NOT clamp vise on reservoir tube or mounting threads. Check rubber grommets for deterioration and replace as necessary.
3. Operate shock by hand at various rates of speed and note resistance. Rebound force is normally stronger than compression force. If resistance is not smooth and constant, replace shock.

To install, reverse removal procedure. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS .

Raise and support vehicle. Remove wheel and tire assembly. Remove stabilizer bar-to-frame retaining bolts and clamps. (Scheme 1) Disconnect stabilizer bar from frame. Remove stabilizer bar-to-lower control arm retaining bolt, nut and washers. Disconnect stabilizer bar from lower control arm, and remove rubber grommets and bushing assembly. Remove stabilizer bar and bushings from vehicle. Check all rubber bushings for excessive wear, deterioration or damage. Replace as necessary.

To install, reverse removal procedure. Bushings should be installed with slit area toward front of vehicle. Apply rubber lubricant to bushings to aid in installation. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS .

1. Raise and support vehicle with jackstand under frame, with control arms hanging free. Remove wheel and tire assembly. Remove shock absorber. See «SHOCK ABSORBERS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) .
2. Install Spring Remover (J-23028-01 ) on floor jack. Position assembly under lower control arm so bushings seat in grooves of spring remover. WARNING: Securely bolt Spring Remover (J-23028-01 ) to floor jack, and install safety chain through lower control arm and coil spring to prevent personal injury.
3. Remove stabilizer bar-to-lower control arm retaining bolt, nut and washers. Disconnect stabilizer bar from lower control arm, and remove rubber grommets and bushing assembly. Raise floor jack to release spring tension on lower control arm pivot bolts. Install safety chain around coil spring and through lower control arm.
4. Remove lower control arm pivot bolts and nuts (rear bolt and nut first). Carefully lower floor jack until all tension is released from coil spring. Remove safety chain and coil spring from vehicle.

1. Position coil spring onto lower control arm. Ensure spring insulator is in place. Raise control arm with spring remover and floor jack. Ensure coil spring is properly positioned, with end of lower spring coil covering one drain hole in lower control arm, and clear of or partially covering other drain hole. NOTE: Coil spring must be positioned with tape at lowest position. Bottom of spring is coiled helical, and top is coiled flat with a gripper notch near end of spring coil.
2. Install lower control arm pivot bolts/nuts (front bolt and nut first). Pivot bolts must be installed with nuts toward rear of vehicle. To complete installation, reverse procedure. Tighten bolts/ nuts to specs. See «TORQUE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) . Lower vehicle and check wheel alignment. See the «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(/gmc/suburban/i-1992-1999/remont/wheel-alignment/#wheel-alignment-specifications-procedures) article in the WHEEL ALIGNMENT section.

1. Raise and support vehicle with jackstand under frame, with control arms hanging free. NOTE: DO NOT place jackstand under lower control arm. Spring tension is needed to break loose ball joint stud.
2. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove hub/rotor assembly. Remove splash shield. Remove cotter pin and nut from tie rod end. Use Tie Rod Remover (J-6627-A ) to separate tie rod end from steering knuckle.
3. If replacing steering knuckle, carefully remove steering knuckle grease seal. Position floor jack under lower control arm between ball joint and spring seat. Raise floor jack until lower control arm is just supported. CAUTION: Support lower control arm with floor jack during removal and installation of steering knuckle.
4. Remove cotter pins and nuts from upper and lower ball joints. Using Ball Joint Separator (J-23742 ), separate ball joint studs from steering knuckle. (Scheme 2) Raise upper control arm to disengage ball joint stud from steering knuckle. Remove steering knuckle.

Inspect tapered holes in steering knuckle for out-of-round, deformation or damage. Inspect spindle for worn or damaged threads. Replace steering knuckle as necessary.

1. To install, reverse removal procedure. Install NEW grease seal on steering knuckle (if removed). Tighten ball joint stud nuts to align cotter pin holes as necessary. Install tie rod end stud into steering knuckle.
2. Install Steering Linkage Installer (J-29193 ) or (J-29194 ). Tighten steering linkage installer to 40 ft. lbs. (54 N.m) to seat tie rod taper. Remove steering linkage installer and install tie rod end stud nut.
3. To complete installation, reverse removal procedure. Adjust wheel bearings. See «FRONT WHEEL BEARINGS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd__front-wheel-bearings) under ADJUSTMENTS. Tighten bolts/nuts to specs. See «TORQUE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) . Lower vehicle and check wheel alignment. See procedures in the «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(/gmc/suburban/i-1992-1999/remont/wheel-alignment/#wheel-alignment-specifications-procedures) article in the WHEEL ALIGNMENT section.

Scheme 2

1. Raise and support vehicle with jackstand under lower control arm, between ball joint and spring seat. Jackstand must remain under lower control arm during upper ball joint servicing to maintain lower control arm and coil spring positioning.
2. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove grease fitting and cotter pin from upper ball joint stud. Remove upper ball joint stud nut.
3. Install Ball Joint Separator (J-23742 ) between upper and lower ball studs. (Scheme 2) Extend bolt on ball joint separator to loosen ball joint stud from steering knuckle. Remove ball joint separator. Separate ball joint from steering knuckle.
4. Using drill motor and 1/8" (3.18 mm) drill bit, drill 1/4" (6.35 mm) deep hole in ball joint retaining rivets. Using 1/2" (12.7 mm) drill bit, drill out rivet heads. Using a hammer and small punch, drive out rivets and remove upper ball joint from upper control arm.

To install, reverse removal procedure. Use NEW nuts and bolts to install ball joint into upper control arm. Install grease fitting and lubricate NEW ball joint. Tighten bolts and nuts to specification. See TORQUE SPECIFICATIONS . Lower vehicle and check wheel alignment. See the WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES article in the WHEEL ALIGNMENT section.

1. Raise and support vehicle with jackstand under lower control arm between ball joint and spring seat. Jackstand must remain under lower control arm during lower ball joint servicing to maintain lower control arm and coil spring positioning.
2. Remove wheel and tire assembly. Remove brake caliper, and wire aside. DO NOT allow brake caliper to hang by brakeline. Remove grease fitting, rubber grease seal and cotter pin from lower ball joint stud. Remove lower ball joint stud nut.
3. Install Ball Joint Separator (J-23742 ) between upper and lower ball studs. (Scheme 2) Extend bolt on ball joint separator to loosen ball joint stud from steering knuckle. Remove ball joint separator. Separate ball joint from steering knuckle.
4. Place a wooden block between upper control arm and frame to keep steering knuckle assembly aside. Obtain "C" Clamp (J-9519-30 ) and Removers (J-9519-7 and J-9519-28 ) from Ball Joint Remover/Installer Set (J-9519-D ), and assemble on lower control arm. (Scheme 3) Remove ball joint from lower control arm.

1. Obtain "C" Clamp (J-9519-30 ) and Installer (J-9519-16 ) from ball joint remover/installer set, and assemble on lower control arm. (Scheme 3) Reverse removal procedure to install ball joint into lower control arm. Ensure bleed vent in rubber grease seal is facing forward. Install grease fitting and lubricate NEW ball joint.
2. To complete installation, reverse procedure. Tighten bolts /nuts to specs. See «TORQUE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd). Lower vehicle and check wheel alignment. See the «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(/gmc/suburban/i-1992-1999/remont/wheel-alignment/#wheel-alignment-specifications-procedures) article in the WHEEL ALIGNMENT section.

Scheme 3

1. Raise and support vehicle with jackstand under lower control arm, between ball joint and spring seat. Ensure jackstand remains under lower control arm during upper control arm servicing to maintain lower control arm and coil spring positioning.
2. Remove wheel and tire assembly. Remove air cleaner extension (if necessary). Remove brakeline bracket from upper control arm. Remove grease fitting and cotter pin from upper ball joint stud. Remove upper ball joint stud nut. Install Ball Joint Separator (J-23742 ) between upper and lower ball studs. (Scheme 2) Extend bolt on ball joint separator to loosen ball joint stud from steering knuckle. Remove ball joint separator. Separate ball joint from steering knuckle.
3. Remove upper control arm-to-frame pivot bolts and nuts. Remove upper control arm.

1. To install, reverse removal procedure. On vehicles without pivot shaft, ensure upper control arm pivot bolt heads face each other, and are tightened to specification with vehicle at riding height.
2. Tighten bolts and nuts to specification. See the «TORQUE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) . Lower vehicle. Check wheel alignment. See the «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(/gmc/suburban/i-1992-1999/remont/wheel-alignment/#wheel-alignment-specifications-procedures) article in the WHEEL ALIGNMENT section.

UPPER CONTROL ARM BUSHINGS

Note. Upper control arm and bushings are serviced as an assembly. See above.

1. Raise and support vehicle with jackstand under frame, with control arms hanging free. Remove wheel and tire assembly. Remove coil spring. See «COIL SPRINGS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) . Separate lower ball joint from steering knuckle. See «LOWER BALL JOINT»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) .
2. Separate lower control arm from steering knuckle and carefully maneuver out of opening in splash shield. Remove lower control arm-to-frame pivot bolts and nuts (rear bolt and nut first). Remove lower control from vehicle.

1. To install, reverse removal procedure. Use NEW nuts on lower control arm pivot bolts. Install lower control arm pivot bolts and nuts (front bolt and nut first). Ensure lower control arm pivot bolts are installed with bolt heads facing toward front of vehicle, and are tightened to specification with vehicle at riding height.
2. Tighten bolts/nuts to specs. See «TORQUE SPECIFICATIONS»(/gmc/suburban/i-1992-1999/remont/suspension-front/#suspension-front-coil-spring-2wd) . Lower vehicle and check wheel alignment. See procedures in the «WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES»(/gmc/suburban/i-1992-1999/remont/wheel-alignment/#wheel-alignment-specifications-procedures) article in the WHEEL ALIGNMENT section.

LOWER CONTROL ARM BUSHINGS

Note. Bushing replacement procedure is not available from manufacturer for Pickup.

Scheme 4

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• WHEEL ALIGNMENT SPECIFICATIONS & PROCEDURES
• RIDING HEIGHT ADJUSTMENT
• TORQUE SPECIFICATIONS
• FRONT WHEEL BEARINGS