Repairing the Trunk and the Frame Rails

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This page will detail the replacement of the panels that make up the trunk along with the replacement of the rear frame rails.  These panels did not appear to be in that bad of shape, but once I started replacing the rear frame rails I saw how bad these panels really were. 

Before removing any metal for this project I leveled the car using jack stands.  I leveled it left to right using the taillight panel and the front lower radiator cross member for reference.  For the front to back level I used the rocker panels.  After the car was leveled I used a plumb bob to transfer the location of the existing frame rails to my concrete floor.  At all of my reference points I drilled a small hole in the floor to ensure that my mark would not be lost.  Next I took measurements of these marks to record the distance between the frame rails and the diagonal measurement of the frame rails.  Finally I measured the distance from my reference points to the concrete floor.  All of this was recorded and will be used to ensure that the new frame rails go back in the exact same place that the old ones were.

The next few pictures show views of the trunk before and after pictures of the trunk and frame rails. Some of the befores don't really look too bad, but once I started removing the paint to find the spot welds I uncovered massive amounts of rust that would have to be repaired.  Both trunk sides, the rear trunk brace, both wheel wells, the taillight panel, and the quarter panel extension bracket had to be cut out and replaced.

Driver's Side trunk before

Driver's Side trunk after

Driver's side with the trunk side removed.  These panels are removed by drilling out the spot welds that attach it to the frame rail, inner wheel well, trunk transition, and rear trunk brace.

After

This is a picture with passenger's side trunk side removed.  It is removed using the same process as the driver's side.

After with the wheel well and quarter panel were replaced

This brace to the inner wheel well was removed for easier access to the spot welds that hold the frame rail in.  These spot welds could be removed from underneath the car, but I needed to remove this piece anyway so that I could replace the wheel well.

This is a picture with the brace removed

While removing the frame rail I discovered that the trunk to rear seat transition pan was rusted in multiple places so I decided to replace it.  Rather than drilling out all of the spot welds that attach the frame rail to the transition panel I took a Sawzall to it.  The rest of the frame rail was removed by drilling out the spot welds that held it in.  The rear floor pan extention was rusted as well and was removed so that a new pan could be welded in.

As I mentioned earlier the trunk transition pan needed to be replaced (also purchased from CJ Pony Parts).  This is accomplished by drilling out the spot welds that attach it to the wheel wells, floor pan and the existing frame rail.  Unfortunately when I removed the spot welds from the frame rail the torque box was so badly rusted that it could no longer hold the weight of the frame rail, and it collapsed under its own weight.  Luckily when I leveled the car prior to removing any sheet metal I transferred all of my frame reference points to the concrete floor using a plumb bob (then I drilled a small hole in the concrete floor at my points of reference so that I my reference points don't become rubbed off) so I do not have to reference off of the existing frame rail.  I can line everything up with the marks in the concrete.

Here is a view with the wheel well removed.  This is removed by drilling out all of the spot welds on the inner flange of the wheel well.  Then you have to drill out all of the spot welds on the lip of the quarter panel where the quarter panel and the wheel well meet.  Finally there are between 8 & 10 Spot welds in the wheel well that attach the wheel well to the structural members inside of the quarter panel.  If you remove the paint in the center  area of the wheel well between the 10 o'clock and 12 o'clock positions (looking from the outside of the car) you should be able to see where the spot welds are. Last remove the few spot welds that attach the wheel well to the trunk hinge brace, and with a little persuasion the wheel well will come out.

Before removing both wheel wells it is necessary to add some bracing to the car.  It becomes very week when this much metal is removed.  The extra metal that you see in the picture is the bracing that I temporarily welded in to strengthen the car's shell. 

I also clamped a piece of wood to the taillight panel to ensure that it did not sag once the quarter panel is removed.  Please see The Quarter Panel Installation page to view how the quarter panels were replaced.

The taillight panel was removed by drilling out all of the spot welds that were holding it in.  I clamped a brace across the trunk to ensure that the panels did not spread apart.  Before removing the panel make sure that it is level across the top of the taillight panel.

The old taillight panel extensions were rusted beyond repair.  I used ones from a donor car.  I do not believe that they are reproduced for a coupe.

Finally the replacement panel was welded in place.  Make sure that the panel is level just like the one that was removed.

Finally it is time to put the frame back together.  Everything was coated with a weld through primer to inhibit future corrosion.  Next I clamped the rear trunk brace to the taillight panel, the torque boxes to the floor pans and the rear of the frame rails to the rear trunk brace.  I adjusted everything so that it lined up with my original marks and height measurements.  I also checked across the two frame rails to ensure that they were level.  This is why it is important to level the car before you start this project.  Once I had everything lined up I welded it in place.

Next I welded in the rear floor extention

After welding in the rear floor extension I realized that I should of put the transition pan in first because it goes underneath the rear floor pan extension.  Then while trying to install the transition pan I realized that it would have been much easier to install it at the same time that the frame rails were installed.  If you are performing this job do yourself a favor and install the transition pan at the same time that you are installing the frame rails.  Once the transition pan was in (after about 3 hours of screwing around) I welded it to the floor pan and wheel wells.  It also gets welded to the frame rails on the underside.  Please note that it may be necessary to use a long clamp to draw the frame rails into the tabs on the transition pan.

Finally the trunk drop offs were installed. First I dry fitted them in place.  Then from the underside I traced where the frame rail made contact with the panel.  Next I removed the panel and used the tracing to determine where to drill holes for spot welding the panel to the frame rail.  Before welding the panels in it is very important to make sure that the gas tank will fit.  I screwed the gas tank in place and then welded them in place.  The last thing to do to complete the repair is to grind all of the welds flat to make them look like they are factory spot welds (or close to it)