Removal Procedure
The re-designed frame assembly for the new S/T Utility is a mild, steel hydroformed frame assembly. A front frame service section consisting of the left and right frame ends, body, and radiator support mounting brackets and front connecting cross tube is available. If damage permits, locate and cut off the front 420 mm (16.5 in) portion of the frame assembly first along the die mark indicators and through the sway bar mounting brackets. The front and rear body mounts, radiator support mounts, sway-bar brackets, steering gear and transmission cross-member can be ordered and replaced separately.
Scheme 2
- Remove all of the related panels and components including the front bumper assembly and the sway bar brackets.
- Locate the two die-marks on each frame. The die marks are located 420 mm (16.5 in) rearward from each front frame rail end on the top and bottom side of each rail.
- Apply masking tape over the die-marks and down each frame rail side as shown, for the cut location.
- Cut each frame at the rear edge of the tape line and through the sway bar bracket using a reciprocating saw or equivalent, as shown.
- Cut the sway bar bracket in half.
- Remove the damaged frame section.
- Remove and discard the remaining sway bar bracket attached to the undamaged portion of the frame using a cut-off wheel or equivalent.
Installation Procedure
- Grind the existing frame rail seam to taper seam at a 45 degree angle.
- Prepare all of the attaching surfaces as necessary.
- Apply the weld-thru primer to all of the welded surfaces.
- Position the service frame section to the existing frame and clamp in place.
- Continuous-weld the upper and lower horizontal joints from corner to corner.
- Continuous-weld the inner and outer vertical joints from corner to corner.
- Position the new sway bar brackets and clamp in place.
- Continuous-weld the sway bar bracket in place as noted from the original parts.
- Clean and prepare all of the welded surfaces.
- Install all of the related panels and components.
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the fuel tank shield. Refer to «Fuel Tank Shield Replacement (Trailblazer, Envoy)»(ref-191509-S41940456182005091600000) or «Fuel Tank Shield Replacement (Trailblazer EXT, Envoy XL)»(ref-191509-S01856295452005091600000) .
- If vehicle is a short wheel base (Trailblazer, Envoy, Bravada), remove the evaporative emission (EVAP) canister from its mounting bracket. Do not disconnect the canister lines. Refer to «EVAP CANISTER»(ref-149799-S15389290402002102500000) in Engine Controls.
- Support the transmission with a transmission jack.
- Remove the transmission mount to the transmission support retaining nuts.
- Remove the lower transmission support to the frame mounting bolts.
- Remove the upper transmission support to the frame mounting bolts.
- Remove the transmission support from the frame.
- Install the transmission support to the frame.
- Install the upper transmission support to the frame mounting bolts. Tighten: Tighten the upper transmission support to the frame mounting bolts to 80 N.m (59 lb ft).
- Install the lower transmission support to the frame mounting bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
- Lower the transmission onto the transmission support.
- Install the transmission mount to the transmission support retaining nuts. Tighten: Tighten the transmission mount to the transmission support retaining nuts to 46 N.m (35 lb ft).
- If vehicle is a short wheel base (TrailBlazer, Envoy, Bravada), install the evaporative emission (EVAP) canister. Refer to «EVAP CANISTER»(ref-149799-S15389290402002102500000) in Engine Controls.
- Install the fuel tank shield. Refer to «Fuel Tank Shield Replacement (TrailBlazer, Envoy)»(ref-191509-S41940456182005091600000) or «Fuel Tank Shield Replacement (TrailBlazer EXT, Envoy XL)»(ref-191509-S01856295452005091600000) .
- Lower the vehicle.
Scheme 3
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the engine shield mounting bolts.
- Remove the engine shield.
- Remove the rear lower control arm bracket to frame mounting bolts.
- Remove the steering gear crossmember mounting bolts.
- Remove the steering gear crossmember.
- Install the steering gear crossmember.
- Install the steering gear crossmember mounting bolts. Tighten: Tighten the steering gear crossmember mounting bolts to 50 N.m (37 lb ft).
- Install the rear lower control arm bracket to frame mounting bolts. Tighten: Tighten the rear lower control arm bracket to frame mounting bolts to 240 N.m (177 lb ft).
- Install the engine shield.
- Install the engine shield mounting bolts. Tighten: Tighten the engine shield mounting bolts to 25 N.m (18 lb ft).
- Lower the vehicle.
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the front steering gear crossmember rear mounting bolts.
- Remove the rear steering gear crossmember mounting bolts.
- Remove the rear steering gear crossmember from the vehicle.
Scheme 4
- Install the rear steering gear crossmember to the vehicle.
- Install the rear steering gear crossmember mounting bolts. Tighten: Tighten the rear steering gear crossmember mounting bolts to 50 N.m (37 lb ft).
- Install the front steering gear crossmember rear mounting bolts. Tighten: Tighten the front steering gear crossmember mounting bolts to 50 N.m (37 lb ft).
- Lower the vehicle.
Scheme 5
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the 2 mounting bolts from the frame brace.
- Remove the frame brace from the frame.
- Install the frame brace to the frame using the 2 mounting bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
- Lower the vehicle.
Scheme 6
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the mounting bolts (2) from the frame brace (1).
- Remove the frame brace (1) from the frame.
- Install the frame brace (1) to the frame using the mounting bolts (2). Tighten: Tighten the bolts to 50 N.m (37 lb ft).
- Lower the vehicle.
Properly support the frame when you change the body mounts. If only one mount is changed, lower the entire side on which the mount in placed in order to provide clearance for the mount.
- Raise the vehicle slightly on a hoist. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Place jack stands under the body on the side of the vehicle that the mounts will be placed.
- Remove the body mount bolt, retainer, and lower cushion (1) from the radiator support.
- Remove the body mount bolts, retainers, and lower cushions (1) from the 5 other mount locations.
- Lower the hoist enough in order to leave the body supported by the jack stands.
- Remove the upper cushions (2) from the vehicle.
Scheme 7
- Install the upper cushions (2) to the vehicle.
- Raise the frame slightly on the hoist.
- Install the lower cushions, retainers, and bolts to the 5 body mount locations. Tighten: Tighten the bolts to 80 N.m (59 lb ft).
- Install the lower cushion, retainer, and bolt to the radiator support. Tighten: Tighten the bolts to 80 N.m (59 lb ft).
- Remove the grille. Refer to «GRILLE REPLACEMENT (GMC)»(ref-189853-S04684449472005091200000) , «GRILLE REPLACEMENT (CHEVROLET)»(ref-189853-S18478283762005091200000) or «GRILLE REPLACEMENT (OLDSMOBILE)»(ref-189853-S42800214712005091200000) .
- Remove the front fascia. Refer to «FASCIA REPLACEMENT - FRONT BUMPER (CHEVROLET, GMC)»(ref-191325-S40361602282005091500000) or «FASCIA REPLACEMENT - FRONT BUMPER (OLDSMOBILE)»(ref-191325-S06657705282005091500000) .
- Remove the front impact bar. Refer to «IMPACT BAR REPLACEMENT - FRONT BUMPER»(ref-191325-S28738832802005091500000) .
- Place the impact bar on a clean, prepared surface.
- Remove the bolt that retains the tow hook to the impact bar.
- Remove the tow hook from the impact bar.
- Install the tow hook to the impact bar, ensuring that the locating pin is properly indexed to the impact bar.
- Install the bolt which retains the tow hook to the impact bar. Tighten: Tighten the bolt to 50 N.m (37 lb ft).
- Install the impact bar. Refer to «IMPACT BAR REPLACEMENT - FRONT BUMPER»(ref-191325-S28738832802005091500000) .
- Install the fascia. Refer to «FASCIA REPLACEMENT - FRONT BUMPER (CHEVROLET, GMC)»(ref-191325-S40361602282005091500000) or «FASCIA REPLACEMENT - FRONT BUMPER (OLDSMOBILE»(ref-191325-S06657705282005091500000) .
- Install the grille. Refer to «GRILLE REPLACEMENT (GMC)»(ref-189853-S04684449472005091200000) , «GRILLE REPLACEMENT (CHEVROLET)»(ref-189853-S18478283762005091200000) or «GRILLE REPLACEMENT (OLDSMOBILE)»(ref-189853-S42800214712005091200000) .
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) .
- Remove the bolts that retain the assist step support brackets to the body.
- Remove the assist step assembly from the vehicle.
- Place the step assembly on a clean, prepared surface.
- Remove the nuts (1) that retain the assist step to the support brackets.
- Remove the support brackets from the assist step.
- Position the assist step to the support brackets. Install the nuts (1) that retain the assist step to the support brackets. Tighten: Tighten the nuts to 25 N.m (18 lb ft).
- Position the assist step assembly to the vehicle.
- Install the bolts that retain the support brackets to the body. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
- Lower the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) .
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) .
- Remove the nuts (1) that retain the assist step to the assist step support brackets.
- Remove the assist step from the support brackets.
- Place the assist step on a clean, prepared surface.
- Release the fasteners (2) that retain the assist step pad to the assist step.
- Remove the assist step pad from the assist step.
- Install the assist step pad to the assist step, ensuring that the fasteners (2) are fully seated.
- Position the assist step to the vehicle. NOTE: Refer to Fastener Notice in «CAUTIONS & NOTICES»(ref-175132-S27550240982005041500000) . Install the nuts (1) that retain the assist step to the assist step support brackets. Tighten: Tighten the nuts to 25 N.m (18 lb ft).
- Lower the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) .
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the frame brace mounting bolts.
- Remove the frame brace.
- Remove the fuel tank shield to the frame retaining bolts and nut.
- Remove the fuel tank shield from the frame.
- Install the fuel tank shield to the frame.
- Install the fuel tank shield to the frame retaining bolts and nut. Tighten: Tighten the fuel tank shield to the frame retaining bolts and nut to 25 N.m (18 lb ft).
- Install the frame brace.
- Install the frame brace mounting bolts. Tighten: Tighten the frame brace mounting bolts to 50 N.m (37 lb ft).
- Lower the vehicle.
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the frame brace mounting bolts.
- Remove the frame brace.
- Remove the fuel tank shield to the frame retaining bolts and nut.
- Remove the fuel tank shield from the frame.
- Install the fuel tank shield to the frame.
- Install the fuel tank shield to the frame retaining bolts and nut. Tighten: Tighten the fuel tank shield to the frame retaining bolts and nut to 25 N.m (18 lb ft).
- Install the frame brace.
- Install the frame brace mounting bolts. Tighten: Tighten the frame brace mounting bolts to 50 N.m (37 lb ft).
- Lower the vehicle.
Scheme 8
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the radiator support shield mounting nuts and bolts.
- Remove the radiator support shield.
- Install the radiator support shield.
- Install the radiator support shield mounting nuts and bolts. Tighten: Tighten the radiator support shield mounting nuts to 17 N.m (13 lb ft).
- Lower the vehicle.
- Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-189249-S38643755882005090600000) in General Information.
- Remove the engine shield mounting bolts.
- Remove the engine shield.
- Install the engine shield.
- Install the engine shield mounting bolts. Tighten: Tighten the engine shield mounting bolts to 25 N.m (18 lb ft).
- Lower the vehicle.