How to Shorten a VW Pan
David Helland - Club Member #50
1 of 4
don't know the complete history of why the Meyers Manx was designed
to be 14-1/4 inches shorter than a stock VW but I am sure that the
result is the Manx has amazing off-road handling characteristics.
Whatever inspired Bruce has provided us with endless hours fun.
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
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 location on the frame where the 14-1/4 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 14-1/4 inches straight across the frame and then cutting
darts out of the rear half to make the two sides match.
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.
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 fame 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.
frame now needs to be cleaned and prepared before shortening begins.
The engine must be removed because it is heavy and the pan must
be turned over to weld the bottom. Open the access hole at the front
of the frame between the front torsion bar tubes and remove the
shift rod after detaching it from the front of the transmission.
Leave the front suspension on the pan to provide necessary points
for measuring and aligning the chassis. Clean the thick tar based
sound deadening material from the entire pan so that the metal can
be cleaned of rust and eventually painted. The tar can be removed
by using a chisel and hammer, but an air chisel does this quickly.
The tar can also be removed by heating the metal near the tar to
cause it to melt away from the metal (this is a stinky process).
You must then remove the rear brake drums and take out the emergency
brake cables. Disconnect the hydraulic brake line at the tee connector
on the rear suspension fork. Pull the brake line toward the front
of the chassis by bending open the tabs that hold the line to the
pan. You will also have to remove the foot pedal assembly to remove
the clutch cable and accelerator cable.