VEHICLE CHECKS
Check following before making wheel alignment adjustments
- Tire pressure must be inflated to manufacturer's recommended specification. Tires should be equal in size and type. Runout must not be excessive. Tires and wheels should be in balance.
- Wheel bearings must be properly adjusted. Steering linkage and suspension must not have excessive wear and/or looseness. Check for wear in tie rod ends and ball joints.
- Steering gear box must not have excessive play. Check and adjust to manufacturer's specification.
- Vehicle must be at correct ride height with full fuel load and spare tire in vehicle. No extra load should be on vehicle.
- Vehicle must be level with floor and with suspension settled. Jounce front and rear of vehicle several times and allow it to settle to normal ride height.
- Ensure steering wheel spokes are centered with front wheels in straight-ahead position. Correct by shortening one tie rod adjusting sleeve and lengthening opposite sleeve in equal amounts.
- Ensure wheel lug nuts are tightened to proper specification. See «TORQUE SPECIFICATIONS»(ref-54959-S00398963862001011800000) .
"C" & "K" Series
- Original control arm does not allow adjustment of camber and caster. Camber and caster may be adjusted only by using Adjustment Kit (J 38794). Raise vehicle and support under lower control arms. Remove and discard upper control arm-to-frame bracket bolts, nuts and washer.
- Remove large washers welded to upper control arm frame brackets. Remove weld beads from upper control arm bracket. Grind area smooth. Install adjustment cams to bracket. (Scheme 2)
- Install bolt. Adjust camber and caster to correct specifications by rotating bolt head. See «ALIGNMENT SPECIFICATIONS»(ref-54959-S03305617812001011800000). Tighten nuts to specification. See «TORQUE SPECIFICATIONS»(ref-54959-S00398963862001011800000).
Scheme 2
Astro, Commercial Van, Safari, Van & "S" Series (2WD)
Camber and caster angle may be adjusted using shims. (Scheme 3) Loosen upper control arm shaft-to-frame nuts. Remove original shims from bolts, and add or remove shims to meet specification. See ALIGNMENT SPECIFICATIONS. Tighten nuts to specification when servicing is complete. See TORQUE SPECIFICATIONS.
Scheme 3
Lumina APV, Silhouette & Trans Sport
- Caster is not adjustable. Measure caster to check for bent or damaged parts. See «ALIGNMENT SPECIFICATIONS»(ref-54959-S03305617812001011800000). Replace damaged components if necessary.
- For camber adjustment, loosen strut-to-knuckle bolts enough to allow movement. (Scheme 4) Adjust camber to specification by moving top of wheel in or out. See «ALIGNMENT SPECIFICATIONS»(ref-54959-S03305617812001011800000). Tighten strut-to-knuckle bolts to specification. See «TORQUE SPECIFICATIONS»(ref-54959-S00398963862001011800000).
Scheme 4
Astro & Safari AWD & "T" Series 4WD
Caster and camber adjustments are made by means of cams on upper control arm frame attaching bolts. (Scheme 5) Loosen upper control arm-to-frame attaching nuts. Rotate cam by rotating bolt head. Adjust caster and camber to specification. See ALIGNMENT SPECIFICATIONS.
Tighten nuts to specification. See TORQUE SPECIFICATIONS .
Scheme 5
Scheme 5: Astro & Safari AWD & "T" Series 4WD
ASTRO & SAFARI
| Application | Preferred | Range |
|---|
| Camber (1) (3) |
| 2WD | 0.8 | 0.3-1.3 |
| 4WD | 0.89 | 0.49-1.29 |
| Caster (1) (3) |
| 2WD | 2.7 | 2.2-3.2 |
| 4WD | 2.0 | 1.5-2.5 |
| Toe-In (2) |
| 2WD | .1 (2.5) | 0.05-0.15 (1.5-4) |
| 4WD | 0.05 (-1.5) | 0.1-0 (-2.5-0) |
| (1) Measurement in degrees. (2) Measurement in inches (mm). (3) Left and right adjustments must be within 0.5 degree of each other. |
| (1) | Measurement in degrees. |
| (2) | Measurement in inches (mm). |
| (3) | Left and right adjustments must be within 0.5 degree of each other. |
ALIGNMENT SPECIFICATIONS (ASTRO & SAFARI)
C 15/25 PICKUP, SIERRA & SUBURBAN (2WD)
| Application | Preferred | Range |
|---|
| Camber (1) (3) | 0.5 | 0-1 |
| Caster (1) (3) | 3.75 | 2.75-4.75 |
| Toe-In (2) | 0.12 (3) | 0.02-0.22 (0.5-5.5) |
| (1) Measurement in degrees. (2) Measurement in inches (mm). (3) Left and right adjustments must be within 0.5 degree of each other. |
| (1) | Measurement in degrees. |
| (2) | Measurement in inches (mm). |
| (3) | Left and right adjustments must be within 0.5 degree of each other. |
ALIGNMENT SPECIFICATIONS (C 15/25 PICKUP, SIERRA & SUBURBAN (2WD))
| Application | Preferred | Range |
|---|
| Camber (1) | 1.25 | (3) .75-1.50 |
| Caster (1) | 5.0 | (3) Nominal |
| Toe-In (2) | .06 | 0.0-.12 (0.0-3.0) |
| (1) Measurement in degrees. (2) Measurement in inches (mm). (3) Reference only, no means of adjustment provided. |
| (1) | Measurement in degrees. |
| (2) | Measurement in inches (mm). |
| (3) | Reference only, no means of adjustment provided. |
ALIGNMENT SPECIFICATIONS (C 35 CAB & CHASSIS (2WD; I-BEAM)
G SERIES VAN
| Application | Preferred | Range |
|---|
| Camber (1) | 0.5 | 0-1 |
| Caster (1) | (3) | (3) |
| Toe-In (2) | 0 (0) | To 0.05 (-1.5 to 1.5) |
| (1) Measurement in degrees. (2) Measurement in inches (mm). (3) (Scheme 7)for caster specifications. |
| (1) | Measurement in degrees. |
| (2) | Measurement in inches (mm). |
ALIGNMENT SPECIFICATIONS ("G" SERIES VAN)
Scheme 6
K 15/25 PICKUP, BLAZER, SIERRA, SUBURBAN & YUKON (4WD)
| Application | Preferred | Range |
|---|
| Camber (1) (3) | 0.65 | 0.15-1.15 |
| Caster (1) (3) | 3 | 2-4 |
| Toe-In (2) (4) | 0.12 (3) | 0.02-0.22 (0.5-5.5) |
| (1) Measurement in degrees. (2) Measurement in inches (mm). (3) Left and right adjustments must be within 0.5 degree of each other. (4) Toe-in on left and right side must be set equally per wheel. Steering wheel must be held in straight-ahead position within plus or minus 5.0 degrees. |
| (1) | Measurement in degrees. |
| (2) | Measurement in inches (mm). |
| (3) | Left and right adjustments must be within 0.5 degree of each other. |
| (4) | Toe-in on left and right side must be set equally per wheel. Steering wheel must be held in straight-ahead position within plus or minus 5.0 degrees. |
ALIGNMENT SPECIFICATIONS (K 15/25 PICKUP, BLAZER, SIERRA, SUBURBAN & YUKON (4WD))
LUMINA, SILHOUETTE & TRANS SPORT
| Application | Preferred | Range |
|---|
| Camber (1) (2) |
| Front | 0 | 0.5 to 0.5 |
| Rear | 0.1 | 0.4 to 0.2 |
| Caster (1) |
| Front | 1.3 | 2.3-3.7 |
| Toe-In (3) |
| Front | 0 | 0.1 to 0.1 (-2.5 to 2.5) |
| Rear | 0 | 0.15 to 0.15 (-4 to 4) |
| (1) Measurement in degrees. (2) Left and right adjustments must be within .07 degree of each other. (3) Measurement in inches (mm). |
| (1) | Measurement in degrees. |
| (2) | Left and right adjustments must be within .07 degree of each other. |
| (3) | Measurement in inches (mm). |
ALIGNMENT SPECIFICATIONS (LUMINA, SILHOUETTE & TRANS SPORT)
P SERIES COMMERCIAL VAN
Note. see scheme 5for explanation of Regular Production Option (RPO) codes. (Scheme 7)-7 for camber and caster specifications. (Scheme 9)for alignment measuring points.
Scheme 7
Scheme 7: P SERIES COMMERCIAL VAN
Scheme 8
Scheme 9
"S/T" SERIES PICKUP, BLAZER, BRAVADA, JIMMY & SONOMA
| Application | Preferred | Range |
|---|
| Camber (1) (3) | 0.8 | 0.3-1.3 |
| Caster (1) (3) | 2 | 1.5-2.5 |
| Toe-In (2) | 0.15 (4) | 0.1-0.2 (2.5-5) |
| (1) Measurement in degrees. (2) Measurement in inches (mm). (3) Left and right adjustments must be within 0.5 degree of each other. (4) Toe-in on left and right side must be set equally per wheel. Steering wheel must be held in straight-ahead position within plus or minus 5.0 degrees. |
| (1) | Measurement in degrees. |
| (2) | Measurement in inches (mm). |
| (3) | Left and right adjustments must be within 0.5 degree of each other. |
| (4) | Toe-in on left and right side must be set equally per wheel. Steering wheel must be held in straight-ahead position within plus or minus 5.0 degrees. |
ALIGNMENT SPECIFICATIONS ("S/T" SERIES PICKUP, BLAZER, BRAVADA, JIMMY & SONOMA)
TYPHOON
| Application | Preferred | Range |
|---|
| Camber (1) (3) | 0 | .5-.5 |
| Caster (1) (3) | 3.5 | 3.0-4.0 |
| Toe-In (2) | 0.15 (4) | 0.1-0.2 (2.5-5) |
| (1) Measurement in degrees. (2) Measurement in inches (mm). (3) Left and right adjustments must be within 0.5 degree of each other. (4) Toe-in on left and right side must be set equally per wheel. Steering wheel must be held in straight-ahead position within plus or minus 5.0 degrees. |
| (1) | Measurement in degrees. |
| (2) | Measurement in inches (mm). |
| (3) | Left and right adjustments must be within 0.5 degree of each other. |
| (4) | Toe-in on left and right side must be set equally per wheel. Steering wheel must be held in straight-ahead position within plus or minus 5.0 degrees. |
ALIGNMENT SPECIFICATIONS (TYPHOON)
| Application | Ft. Lbs. (N.m) |
|---|
| Tie Rod Adjustment Sleeve Clamp Bolts | 13 (18) |
| Upper Control Arm Nuts |
| 2WD | 85 (115) |
| 4WD | 107 (145) |
| Wheel Lug Nuts | 100 (136) |
TORQUE SPECIFICATIONS (ASTRO & SAFARI)
| Application | Ft. Lbs. (N.m) |
|---|
| Tie Rod Adjustment Sleeve Clamp Bolts | 14 (19) |
| Upper Control Arm Nuts (1) | 75-90 (100-122) |
| Wheel Lug Nuts |
| Dual Rear Wheels |
| 8 Lug | 140 (190) |
| 10 Lug | (2) 175 (240) |
| Single Wheels | 120 (163) |
| (1) Adjustment Kit (J 38794) must be used on "C" and "K" Series vehicles. (2) Tighten in 2 steps. Initially tighten all studs to 140 ft. lbs. (190 N.m), and then tighten to 175 ft. lbs. (240 N.m). |
| (1) | Adjustment Kit (J 38794) must be used on "C" and "K" Series vehicles. |
| (2) | Tighten in 2 steps. Initially tighten all studs to 140 ft. lbs. (190 N.m), and then tighten to 175 ft. lbs. (240 N.m). |
TORQUE SPECIFICATIONS ("C" & "K" SERIES)
"G" & "P" SERIES
| Application | Ft. Lbs. (N.m) |
|---|
| Tie Rod Adjustment Sleeve Clamp Bolts | 14 (19) |
| Upper Control Arm Nuts |
| G15/25 & R15 | 70 (95) |
| Except G15/25 & R15 | 105 (142) |
| Wheel Lug Nuts |
| Dual Wheels | 140 (190) |
| Single Wheels | 110 (150) |
| "P" Series |
| Dual Wheels (8 Studs) | 140 (190) |
| Dual Wheels (10 Studs) | (1) 175 (240) |
| Single Wheels | 120 (163) |
| (1) Tighten in 2 steps. Initially tighten all studs to 140 ft. lbs. (190 N.m), and then tighten to 175 ft. lbs. (240 N.m). |
| (1) | Tighten in 2 steps. Initially tighten all studs to 140 ft. lbs. (190 N.m), and then tighten to 175 ft. lbs. (240 N.m). |
TORQUE SPECIFICATIONS ("G" & "P" SERIES)
| Application | Ft. Lbs. (N.m) |
|---|
| Strut-To-Knuckle Bolts | 140 (190) |
| Tie Rod Lock Nut | 52 (70) |
| Wheel Lug Nuts | 100 (136) |
TORQUE SPECIFICATIONS (LUMINA APV, SILHOUETTE & TRANS SPORT)
"S" & "T" SERIES
| Application | Ft. Lbs. (N.m) |
|---|
| Tie Rod Adjustment Sleeve Clamp Bolts | 14 (19) |
| Upper Control Arm Nuts |
| "S" Series (2WD) | 65 (88) |
| "T" Series (4WD) | 70 (95) |
| Wheel Lug Nuts | 95 (130) |
TORQUE SPECIFICATIONS ("S" & "T" SERIES)
