Rear Wing Repair1
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Repairing rear wings is often a better option than replacing the whole wing. However, if the wing has been extensively damaged through a traffic accident replacement of the whole wing can be unavoidable. Rust damage is often confined to the lower half of the wing and in this case replacement of the lower section is an option. There are two repair panels available. The first is the forward lower quarter panel which is used if the sills are to be replaced and the second is the lower portion of the wing below the stainless steel strip from door to rear valance. This section describes work involved in replacing the second panel.

This job is normally undertaken together with repairs to the inner wheel arch. The outer half of the inner wheel arch can rust badly where it joins the wing around the wheel arch and may need replacement. This is normally done after the outer wing repair is completed. Assess the need and buy the rear wing repair section and wheel arch repair panel if necessary. The repair to the inner wheel arch panel is described as a separate item.

Before work starts safety precautions should be observed;
  • Disconnect the batteries
  • Ensure that where wheels have been removed, the car is properly supported.
  • Welders and angle grinders will be used and so fire precautions should be taken.
  • Petrol tank, petrol pump and any fuel lines should be removed and/or made safe from sparks or naked flames.
The first thing to do is to remove the old rear wing section so start by removing the rear bumper bar, the light cluster and the stainless side strip. Ensure that the wiring harness is placed well out of harms way. Offer up the new panel and scribe a line along the wing below the swage line to give a rough idea of where the panel will be fixed. Also scribe a line down the rear valance below the bumper. Note that the front edge of the new panel will fit down the curve of the door aperture over the 'B' post and the rear of the panel is attached down the line of the rear light and on down to join the rear panel.

Using an angle grinder carefully cut along the top of the old section 2 inches (50mm) below the line previously scribed. This leaves a wide margin for trimming when the new panel is fitted. Take care not to cause any distortion to the metal left on the wing. Use of tin snips etc is not advised but an angle grinder with a metal cutting wheel is ideal. Cut on down the door curve leaving 1 inch (25mm) of spare metal. There is no need to cut down the curve of the sill because the panel is not attached at this point and do not cut along the bottom towards the wheel arch at this stage. The rear part of the sill is immediately behind this section and can easily be damaged by the grinder. At the rear, cut down the line of the rear light aperture leaving 1 inch (25mm) of spare metal but do not follow the line horizontally round the curve to the wing joint. The joint between the rear panel and the new wing can be difficult to weld without a spot welder. If the old wing section at this joint is in good condition it makes more sense to leave it in place and make a joint at a more convenient spot. Cut vertically down to the horizontal rear section/wing joint above the bumper recess. Carry on and cut horizontally 1 inch (25mm) above the joint to the line previously scribed down the rear valance. Leave 2 inches (50mm) of spare metal on the valance and cut vertically down the to detach the old wing. Finally, cut around the wheel arch leaving about 1 inch (25mm) of spare metal and the old section now should be free except for the part along the bottom of the sill. Carefully flex the old section away from the sill and make the final cut to remove it taking care not to damage the sill. It only remains to remove the spare metal down the door curve, along the sill bottom edge, down the edge of the rear light cluster and around the wheel arch by drilling out the spot welds. When doing this remember to leave the flanges in good condition because the new panel will later be welded at these points.

The next stage is to trial fit and trim the new panel. This process will take time and plenty of patience. In order to reduce both time and frustration the panel can be attached for trial fitting by Cleco fasteners where clamps cannot be used. The only other alternative is self-tapping screws, which can be time consuming to use. It is important to note that where a panel is removed and re-fitted a number of time it should be re-fitted by the same sequence of fixings each time. If not, it may not be fitted in exactly the same place each time, which makes trimming very difficult.

Before the new panel can be offered up to the wing it requires some trimming. First carefully dress down the flange on the curved section that fits over the sill below the door. It is easy to distort the panel at this point so be careful to support the outside face when using the panel-beating tools. Next, the flange along the top must be removed. This should be done carefully, with the angle grinder, cutting off the bare minimum amount of metal possible and without distortion. Once the flange is remove the panel will become very flexible so handle it with care. Finally, trim off part of the curved section below the rear light cluster aperture at a point where it can be joined to the metal left in place from the old wing.

Next comes fitting the new wing repair panel. Drill 1/8 inch (3mm) holes at 2 inch (50mm) intervals along the new panel's flanges where it will attach to the 'B' post and where it will be attached to the rear light cluster back panel. If the inner wheel arch is not to be replaced, drill further holes at 2 inch (50mm) intervals around the wheel arch flange. Offer the panel up and when it fits snugly in position clamp it at the bottom flange along the sill. Other clamps should also be used on the joint between the rear valance and the lower part of the wing and where the wing joins the rear light cluster panel. Take care when using the clamps to avoid any distortion on outer panels. Once you are happy with the fit, drill 1/8 inch (3mm) holes around the flanges in to correspond with the holes previously drilled in the new panel and insert Cleco fasteners. Also drill holes for Cleco fasteners around the inner wheel arch if appropriate. At this point the panel should be secure but there will be no fasteners along the top edge or in the lower rear valance. Check that the line previously scribed along the top edge of the old wing and around the valance is accurate and if necessary re-scribe the lines. Also scribe a third line at the point where the new panel will join the old panel below the rear light cluster. Remove the new panel and drill 1/8 inch (3mm) holes in it at 2 inch (50mm) intervals around the lower valance and down the third line. These holes should be drilled within 3/16 inch (5mm) of the edge of the metal. This is because the edge where the new panel meets the old panel will be stepped using a Joggler tool or similar to form a flush joint and the overlap of metal will be approximately 3/16 inch (5mm) depending on the tool used. If you have not used a Joggler tool before try it out on an off-cut of metal to gauge the distance between the edge of the metal and the step formed by the tool.

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MGB Roadster Rear Wing Repairs Once the overlap distance has been ascertained, scribe a second line below the top line previously scribed on the remains of the old wing panel to allow for the overlap where the new panel will be joined. Also scribe a second line round the lower rear valance and at the joint below the rear light aperture. Next carefully trim the excess metal back to this second line in each case. Then drill 1/8 inch (3mm) holes at 2 inch (50mm) intervals along the old wing to attach the new repair panel. Using the Joggler tool form a step along the line down the valance and below the light cluster on the old wing/valance. Then form a step along the top of the new panel. Care should be taken to form an even step to achieve a good panel fit. Offer up the new wing panel and ensure it fits snugly in the newly formed steps. Once you are happy with the fit drill through the previously drilled holes and insert Cleco fasteners. You should ensure that you are happy with the fit at this point before welding begins.

Welding is the next stage but before welding begins it is worth painting the inside inaccessible surfaces to protect against future corrosion. Remove the new wing section and punch holes suitable for plug welding in the flanges at approximately ¾ inch (15mm) intervals. Re-fit the panel and ensure it fits securely. As the new panel is finally being fitted seal the curved section between the wing and sill with seam sealant. If left unsealed rain and salty water from the road can be driven into the space between the sill and wing causing trouble for the future. When you are happy with the positioning begin welding. Heat build-up from welding will cause distortion so place plug welds around the flanges at wide intervals and allow the metal to cool before continuing. The flush joints where the steps have been formed must be continuously welded. To minimise distortion, weld in lengths of only ¼ inch (6.5mm) and wait for the metal to cool before continuing. Take plenty of time over this to achieve a good result. After the welding is complete finish with an angle grinder and a minimum amount of filler to cover welding/grinding marks. Alternatively, if you have the necessary skills use lead loading instead of filler. The next step is to fit a new inner wheel arch, which is described in Wheel-arch Repair.

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MGB Rear Wing Repairs    MGB Rear Wing Repairs

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