As soon as I started looking at the rusted out
unibody, it was pretty obvious that the crossmember that supports the
rack and ties the whole front end of the Dodge together would be a critical
component. After cutting out the rusty flooring and and removing the through
bolt that held the crossmember to the unibody (when the subframe was still
in one piece), it became apparent that the crossmember was in excellent
condition. It's formed from a much heavier gauge of steel than the subframe
was, and probably a better grade as well. The picture to the right shows
the driver side rear crossmember mounting hole, which I'll design the new
subframe elements around. You can also see the two driver side brake lines
and the emergency brake cable, which made random cutting a bad idea.
The picture to the left is the remnant of unibody subframe that the crossmember
was originally mounted under. After 22 years, it was the crossmember that
was holding up the subframe element, which was hanging onto the piece extending
up to the shock tower by a thread. I saved it in the hopes it will help me
a little with the layout of the new subframe, which I'll be constructing
from 2" x 3" thin wall steel tubing. You can also see where it was bolted
in the crossmember slot , pretty much all the way to the outside, which I'll
try to duplicate in my own construction, though it's nice to have wiggle
room.
Now I'm including a four video sequence, starting with hacksawing out the
old unibody subframe from the floor just behind the driver's seat. I used
a hacksaw in part for control, the brake lines run right alongside the subframe,
and I knew that one slip with a grinder would have led to new brake lines.
Working with rusty old sheet metal components, I find I don't have to saw
all the way through if there's no angle bent in the remaining metal to give
the joint strength. The vise grips are a handy tool for working the remaining
bits of connecting metal to fatigue it so it breaks off cleanly.
The video to the left below shows the piece of subframe being twisted off
the front stub frame, and it becomes clearer with every step that these elements
were contributing nothing to the structural integrity of the car. The side
frame rails are good, the roof posts are intact, so the whole forms a truss,
which kept the front of the car from falling off. The final video shows the
cross member in profile, so the hole you saw in the photo at the top left
is in the surface that appears on edge. While there wasn't much left of the
drivers side metal between the frame rail and the hump, or between the engine
compartment the back seat, I think we're in decent shape for attachment points.
