Replacing Left B-Pillar Reinforcement (Rear Side Panel And Roof Outer Skin Removed) (M4 Coupe)

Observe procedure for repair stage 3. See REPAIR STAGE 3 .

Use only an approved SPOT-WELDING APPARATUS for repairs!

For stripping and rebuilding operations, refer to the surrounding text of Commercial Service Data (flat rate unit number 41 21 682).

Place vehicle on straightening bench.

Following new body parts are required (see applicable BMW Parts Catalog.):

(1) Middle side frame
(2) Inner side member
Shaped part, B-pillar, inner
Shaped part B-pillar, outer

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Removal

Extended removal of SIDE PANEL :

Mark severance cut (1) in accordance with severance cut on new part and cut.

Attention!

Cut outer metal panel only.

Open welded connections in areas (2).

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Side member section:

Mark and cut severance cut (1) in accordance with specified dimensions.

Attention!

Only cut the outer panel in the area of the jacking point (2).

Measurement a = approx. 20 mm from component edge.

Dimension b=approx. 10 - 15 mm from component edge.

Release welded connections in areas (3) and remove side member section.

Remove cavity sealing (4).

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Open welded connections in areas (1).

Release the B-pillar reinforcement from the inner cavity sealing (2) and remove.

Open welded connections in areas (1).

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Open welded connection in areas (1) and remove B-pillar reinforcement (2).

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New part preparation

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Open welded connections in areas (1) to (3).

Remove the B-pillar reinforcing tube (4).

NOTE: Release the welded connections in areas (1) and (2) from the outer side.

The B-pillar reinforcing tube (4) must be installed separately for accessibility reasons.

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Side sill section:

Mark and perform severance cut (1) in accordance with severance cut on vehicle (2) +15 mm extra material.

In the area of the moulding (3) extra material approx. 5 - 10 mm.

NOTE: In the area of the jacking point (4), joining with overlaps is not performed. Prepare new part for butt welding.

Prepare the areas for overlapping and the areas (5) for plug-welding.

Comply with new part preparation for SIDE PANEL and side sill.

Prepare reinforcement plates at severance cuts.

Prepare new parts for joining by welding in the remaining joining areas.

Adjust new parts to fit with alignment bracket or universal mount and secure.

NOTE: When adjusting the new parts, the panel thickness of the missing side panel must be taken into consideration depending on straightening system manufacturer.

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Different new part preparation for side panel:

Prepare for joining by welding in areas (1).

Prepare the joints in areas (2) and (3) for joining by rivet bonding technology.

Installation

Install new parts and reinforcement plates with alignment bracket or universal mount and weld.

NOTE: When installing the new parts, the panel thickness of the missing side panel must be taken into consideration depending on straightening system manufacturer.

Install the reinforcement tube (2) and MAG weld in the areas (1).

Minimum length of weld seams: 20 mm.

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Weld reinforcement tube in the areas (1).

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Apply sealant to inner CAVITY SEALING (2). Install cavity sealing.

Install new part and weld in areas (1).

install outer cavity sealing.

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Install side sill section and weld in areas (1) to (3).

(4) = Severance cut route on vehicle.

Divergent installation of the side wall:

In areas (1) - (3) rivet side panel with punch rivets.

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Area	Number	Remarks
1	6	Punch rivet N5
2	7	Punch rivet N4
3	6	Punch rivet N5