Pan Shortening
By David Helland - Club Member #50
The VW Bug combines a body shell and chassis to implement a very rigid "monocoque" body. The VW is
not a true "monocoque" because the body can be removed by simply un-bolting it. The remaining chassis
is called the "pan.” The pan consists of a central steel tunnel with front and rear assemblies for attaching
suspension components and a thin sheet metal floor plate to form the bottom of the car. When the body is
removed, the central tunnel of the pan is the only remaining structural component between the front and
rear of the chassis. The tunnel is not a completely rigid structural component in that it will allow some
torsion to occur between the front and rear of the frame.
When shortening the pan it is extremely important to correctly weld the tunnel back together to restore
the structural integrity of the frame. When a fiberglass body is bolted to the frame it regains some of the
"monocoque" characteristics but it is not nearly as rigid as the original VW Bug. If the tunnel is not
correctly welded and strengthened, the car is very likely to break in half. A MIG wire-feed welder is
recommended for the welding; however, I have done the job by steel brazing with oxygen-acetylene gas.
An arc welder is not recommended because the material is so thin that an arc welder will just melt holes in
the metal. It is also very important to keep the alignment of the frame intact. I always spend more time
measuring for accurate alignment than I spend welding.
The body is removed from the frame by first removing all the bolts from the channel under the outer edge
of the frame (an air powered impact wrench does this quickly). There are also four bolts that must be
removed the middle of the underside of the car that are just in front of the rear torsion bar housing. Then
remove the two bolts under the rear wheel wells that attach the body to the rear cast suspension
members. There are also two bolts under the rear seat of the car that attach to the rear cast suspension
members. The last two bolts are located in front of the gas tank and connect to the top of the front
suspension beams. Before you can lift the body off, you must disconnect the steering shaft at the steering
box, remove the speedometer cable, disconnect the heater box control wires, and all remove the wiring
that connects to the engine and the master brake cylinder.
The next task is to lift the body off the chassis. There are several ways to do this. The method I chose in
1966 was to hook a winch to the rafters of my dad's garage. I succeeded in breaking the rafter and
collapsing the roof of the garage onto the VW! It is better to get four helpers, two 12 foot 2x6's, and four
saw horses. First, lift the front of the body off the frame and slip a 2x6 under the wheel wells and support
it on each side with saw horses. Then do the same thing at the rear of the car. When the body is high
enough in the air, the frame can be rolled out from under it. I recently removed a body by myself by
building a large wood frame and using a "come-along" to winch the body into the air.
The location on the frame where the 14-1/2 inches is to be removed is
the straight section of the tunnel directly behind the emergency brake
handle on a line even with the rear of the seat support rails. When
examining the pan it is obvious that because the sides of the VW pan are
not parallel, the two halves are not going to exactly match when they are
put back together. There are several ways to accomplish this feat. The
method that I am going to describe entails cutting out 14-1/2 inches
straight across the frame and then cutting darts out of the rear half to
make the two sides match.
