Suspension - Front (coil) GMC Jimmy Typhoon

DESCRIPTION

Independent front suspension consists of upper and lower control arms with steering knuckle mounted between ball joints. (Scheme 1) On Astro, Jimmy, Safari, Sonoma and "S" Series Blazer & Pickup, upper control arm is mounted on pivot shaft. On "C" Series Pickup, Sierra and Suburban, upper control arm is mounted directly to frame with pivot bolts. On all models, 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 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) should be .001-.005" (.03-.13 mm) on Astro, Jimmy, Safari, Sonoma and "S" Series Blazer & Pickup and .001-.008" (.03-.20 mm) on "C" Series Pickup, Sierra and Suburban. Install dust cap.

RIDING HEIGHT

Note. See ALIGNMENT SPECIFICATIONS/PROCEDURES article in the WHEEL ALIGNMENT Section.

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 Ball Joint (Astro, Jimmy, Safari, Sonoma & "S" Series Blazer & Pickup)

1. Raise and support vehicle with jack stand under lower control arm, near lower ball joint. Ensure upper control arm bumper does not contact frame. Place dial indicator against lower part of wheel rim. Push in on bottom of tire while pulling outward at top. Read dial indicator, then reverse push/pull procedure.
2. Lateral (horizontal) deflection should not exceed .125" (3.18 mm). If deflection is excessive, replace ball joint.
3. With ball joint disconnected from steering knuckle, check to see if ball joint can be rotated by finger pressure. Replace if ball joint can be twisted.

Lower Ball Joint (Astro, Jimmy, Safari, Sonoma & "S" Series Blazer & Pickup)

1. Wear indicator is built into ball joint. Wear is indicated by position of the 1/2" diameter round boss that grease fitting is threaded into. A NEW ball joint has a boss projection of .050" (1.27 mm) beyond cover surface.
2. With vehicle weight on wheels, ensure wear indicator protrudes beyond surface of ball joint cover. Replace ball joint if wear indicator is recessed or even with housing.

Upper & Lower Ball Joints ("C" Series Pickup, Sierra & Suburban)

1. Raise and support vehicle with jack stand 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 brake line. 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 required 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 and nuts to specification. See «TORQUE SPECIFICATIONS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) table at end of article. Adjust wheel bearings. See «FRONT WHEEL BEARINGS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil__front-wheel-bearings) under ADJUSTMENTS. Lower vehicle and check wheel alignment. See 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 table at end of article.

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 table at end of article.

1. Raise and support vehicle with jack stand under frame, with control arms hanging free. Remove wheel and tire assembly. Remove shock absorber. See «SHOCK ABSORBERS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) under REMOVAL & INSTALLATION.
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.

Note. DO NOT apply force on lower control arm and ball joint to remove coil spring. Coil spring can easily be removed by maneuvering spring.

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 and nuts (front bolt and nut first). Pivot bolts must be installed with nuts toward rear of vehicle. To complete installation, reverse removal procedure. Tighten bolts and nuts to specification. See «TORQUE SPECIFICATIONS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) table at end of article. Lower vehicle and check wheel alignment. See ALIGNMENT SPECIFICATIONS/PROCEDURES article in the WHEEL ALIGNMENT Section.

1. Raise and support vehicle with jack stand under frame, with control arms hanging free. NOTE: DO NOT place jack stand 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 brake line. 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/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil__front-wheel-bearings) under ADJUSTMENTS. Tighten bolts and nuts to specification. See «TORQUE SPECIFICATIONS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) table at end of article. Lower vehicle and check wheel alignment. See ALIGNMENT SPECIFICATIONS/PROCEDURES article in the WHEEL ALIGNMENT Section.

Scheme 2

1. Raise and support vehicle with jack stand under lower control arm, between ball joint and spring seat. Jack stand 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 brake line. 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 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 table at end of article. Lower vehicle and check wheel alignment. See SPECIFICATIONS/PROCEDURES article in the WHEEL ALIGNMENT Section.

1. Raise and support vehicle with jack stand under lower control arm between ball joint and spring seat. Jack stand 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 brake line. 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 out of the way. Assemble on lower control arm, "C" Clamp (J-9519-30 ) and Removers (J-9519-7 and J-9519-28 ) from Ball Joint Remover/Installer Set (J-9519-D ). (Scheme 3) Remove ball joint from lower control arm.

1. Assemble on lower control arm, "C" Clamp (J-9519-30 ) and Installer (J-9519-16 ) from ball joint remover/installer set. (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 removal procedure. Tighten bolts and nuts to specification. See «TORQUE SPECIFICATIONS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) table at end of article. Lower vehicle and check wheel alignment. See ALIGNMENT SPECIFICATIONS/PROCEDURES article in the WHEEL ALIGNMENT Section.

Scheme 3

Removal (Astro, Jimmy, Safari, Sonoma & "S" Series Blazer & Pickup)

1. Note location of alignment shims for reassembly. Remove upper control arm pivot shaft-to-frame nut and shim. (Scheme 1) Raise and support vehicle with jack stand under lower control arm, between ball joint and spring seat. Ensure jack stand 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 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. Lift upper control arm, and remove upper control arm pivot shaft-to-frame bolts. Remove upper control arm.

Removal ("C" Series Pickup, Sierra & Suburban)

1. Raise and support vehicle with jack stand under lower control arm, between ball joint and spring seat. Ensure jack stand 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 brake line 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 "C" Series Pickup, Sierra and Suburban without pivot shaft, ensure upper control arm pivot bolt heads face each other, and are tightened to specification with vehicle at riding height.
2. On Astro, Jimmy, Safari, Sonoma and "S" Series Blazer & Pickup, ensure holes in upper control arm shaft align with holes in frame. Ensure alignment shims are installed in original position.
3. On all models, tighten bolts and nuts to specification. See «TORQUE SPECIFICATIONS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) table at end of article. Lower vehicle and check wheel alignment. See ALIGNMENT SPECIFICATIONS/PROCEDURES article in the WHEEL ALIGNMENT Section.

UPPER CONTROL ARM BUSHINGS

Note. Upper control arm bushings are not replaceable on "C" Series Pickup, Sierra and Suburban. Upper control arm and bushings are serviced as an assembly.

Pivot Shaft Bushing Replacement (Astro, Jimmy, Safari, Sonoma & "S" Series Blazer & Pickup)

1. Remove upper control arm from vehicle. See «UPPER CONTROL ARM»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) under REMOVAL & INSTALLATION. Place upper control arm in soft-jawed vise. Remove nuts and retainers from ends of pivot shaft.
2. Using Bushing Remover (J-22269-1 ), a slotted washer and a short piece of pipe (slightly larger than bushing), press bushing and pivot shaft from upper control arm. Repeat procedure for opposite bushing.
3. To install, place pivot shaft in upper control arm. Using Bushing Installer (J-22269-1 ) and small piece of pipe with the same outer diameter as bushing, press NEW bushing into upper control arm and onto pivot shaft.
4. Ensure each bushing is positioned .48-.52" (12.8-13.8 mm) from face of control arm to bushing outer sleeve. Repeat procedure for bushing on opposite end. Install nuts and retainers onto upper control arm pivot shaft ends.

1. Raise and support vehicle with jack stand under frame, with control arms hanging free. Remove wheel and tire assembly. Remove coil spring. See «COIL SPRINGS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) under REMOVAL & INSTALLATION. Separate lower ball joint from steering knuckle. See «LOWER BALL JOINT»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) under REMOVAL & INSTALLATION.
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 and nuts to specification. See «TORQUE SPECIFICATIONS»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) table at end of article. Lower vehicle and check wheel alignment. See ALIGNMENT SPECIFICATIONS/PROCEDURES article in the WHEEL ALIGNMENT Section.

LOWER CONTROL ARM BUSHINGS

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

Front Bushing Replacement (Astro, Jimmy, Safari, Sonoma & "S" Series Blazer & Pickup)

1. Remove lower control arm from vehicle. See «LOWER CONTROL ARM»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) under REMOVAL & INSTALLATION. Place lower control arm in soft-jawed vise. Using a blunt chisel, drive front bushing flare down even with rubber of bushing.
2. Install lower control arm bushing service set. On Astro and Safari, service set includes Receiver (J-21474-5 ), Nut (J-21474-18 ), Bolt (J-21474-19 ), Remover (J-21474-23 ) and Spacer (J-23737 ). (Scheme 4)
3. On Jimmy, Sonoma and "S" Series Blazer & Pickup, service set includes Receiver (J-21474-5 ), Nut (J-21474-18 ), Bolt (J-21474-19 ), Remover (J-21474-23 ) and Spacer (J-22222-5 ). (Scheme 4) On all models, tighten nut until front bushing is removed from lower control arm.
4. To install front bushing, assemble control arm bushing service set. On Astro and Safari, use Installer (J-21474-20 ) and Spacer (J-21474-12 ) with other removal tools of service set. (Scheme 5)
5. On Jimmy, Sonoma and "S" Series Blazer & Pickup, use Remover/Installer (J-21474-8 ) with other removal tools of service set to install NEW bushing. (Scheme 4) Position NEW front bushing into lower control arm with lip side of bushing on outside of lower control arm. Tighten nut until bushing is fully seated into lower control arm.
6. Flare front bushings after installation. On Astro and Safari, install Flaring Die (J-21474-2 ), Installer (J-21474-13 ), Nut (J-21474-18 ), Bolt (J-21474-19 ) and Spacer (J-23737 ). (Scheme 6)
7. On Jimmy, Sonoma and "S" Series Blazer & Pickup, install Flaring Die (J-21474-2 ), Spacer (J-21474-12 ), Installer (J-21474-13 ) and Nut (J-21474-18 ). (Scheme 6) On all models, turn nut on flaring die until bushing is flared approximately 45 degrees. Remove bushing flaring die and service tools.

Scheme 4

Scheme 5

Scheme 6

Rear Bushing Replacement (Astro, Jimmy, Safari, Sonoma & "S" Series Blazer & Pickup)

1. Remove lower control arm from vehicle. See «LOWER CONTROL ARM»(/gmc/jimmy-typhoon/1992-1993/remont/suspension-front/#suspension-front-coil) under REMOVAL & INSTALLATION. Place lower control arm in soft-jawed vise.
2. Install Receiver (J-21474-5 ), Remover (J-21474-8 ), Spacer (J-21474-12 ), Nut (J-21474-18 ), Bolt (J-21474-19 ). (Scheme 7) Tighten nut until rear bushing is removed from lower control arm.
3. Assemble control arm bushing service set. Install Nut (J-21474-18 ), Bolt (J-21474-19 ), Spacer (J-21474-12 ) and Receiver (J-21474-5 ). On Astro and Safari, also use Installer (J-21474-20 ). Position NEW rear bushing into lower control arm with lip side of bushing on outside of lower control arm. Tighten nut until bushing is fully seated into lower control arm.

Scheme 7

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TORQUE SPECIFICATIONS
• FRONT WHEEL BEARINGS