Frame Extension

Frame Extension - Stub Frame, Front

Material:

Removal

NOTE: LH side of front stub frame extension shown, RH side similar.

1. Prepare the vehicle for front stub frame extension removal.
1 Remove the front bumper/body.
2 Vehicles with automatic transmission, remove the transmission.
3 Vehicles with manual transmission, remove the transmission.
4 Remove the engine.
5 Remove the exhaust system components as necessary to access the front stub-to-reinforcement rivets.
6 Remove the power steering gear and any steering components attached to the frame.
7 Vehicles with 4-wheel drive, remove the front drive axle.
8 Vehicles with 2-wheel drive, remove the front axle.
9 Remove all suspension components attached to the front stub frames including the front leaf spring rear shackle bracket or the radius arm pivot bracket.

2. NOTICE: Before this step is carried out, the reinforcement and surrounding frame area must be correctly prepared.

Remove and discard the rivets used to secure the side rail reinforcements to the front stub frame and rear side rail. Separate the weld joints. For additional information, refer to Rivet Replacement. Rivet Replacement











3. Remove the front stub assembly and the side rail reinforcement at the joint.

Installation

1. NOTE: Refer to Specifications for parts identification when installing new stub frames and side rail reinforcements.

Prepare the frame in order to make sure of a good weld adhesion.
1 Using a heat gun, warm up the area in order to soften the frame wax coating. Completely clean the surface of the frame rail under and around the center rail. Use a razor blade in handle to remove all of the frame wax.
2 Use a wax and grease remover for final cleaning of the remaining wax residue.
3 Use a 3-inch grinder to remove the paint from the top flange of the front rail in the areas to be welded.

2. Position the new center rail and align the attaching holes with the front and rear rails.
3. Using the center rail as a template, drill a hole through all of the attaching holes to the replacement bolt nominal size, with a hole tolerance of ±0.005 inch.
4. After drilling, remove any burrs from the holes in order to allow the bolt head and nut to seat correctly.

5. NOTE: The side rail reinforcement must be attached to the rear stub frame first during installation.

Position the front stub assembly and the side rail reinforcements on the frame assembly.

6. NOTE: Install the nuts and bolts so that the nuts are located on the outside of the frame.

Secure the center rail with new nuts (382400-S2) and bolts (391330-S2). Apply Threadlock 262 or equivalent to the bolts before installing the nuts.

- Tighten all fasteners to 53 Nm (39 lb-ft).












7. NOTE:
- The side rail reinforcement must be attached to the rear side rails first during installation.
- To minimize stress concentrations, do not weld at the corners. For additional information, refer to Rivet Replacement. Rivet Replacement

Weld the side rail reinforcement to the front stub frame and the rear side rails.

- Plug weld the top frame flange to the center rail.
- Stitch weld the front rail to the rear rail.







8. Restore the vehicle to operating condition.
1 Install all suspension components that were removed.
2 Vehicle with 2-wheel drive, install the front axle.
3 Vehicles with 4-wheel drive, install the front drive axle.
4 Install the power steering components that were removed.
5 Install the exhaust system components that were removed.
6 Install the engine.
7 Vehicles with manual transmission, install the transmission.
8 Vehicles with automatic transmission, install the transmission.
9 Install the front bumper/body.