04.13.08
Removing the Sub-Chassis
Today, I removed the sub-chassis from the Volkswagen chassis. This was fairly easy to do, but required moving the jack stands around a bit. The sub-chassis is bolted to the main (Volkswagen) chassis in 6 places. There are 2 U-bolts around the lower beam tube at the front end, there are 2 U-bolts around the rear torque rod housings and there are two brackets that connect the sub-frame to the two lower mounting bolts for the transaxle. The frame is going to need to be redesigned as I was able to identify at least three structural flaws in the factory’s design.
First, The front battery box hangs cantilevered in front of the chassis and the rear battery trays hang cantilevered beyond the rear of the chassis. This made the frame bow up longitudinally (fore-to-aft) in the center — under the floor pans. As a result, the bottom flanges of the two main C-channels buckled slightly — not to the point of catastrophic failure but enough to warrant a redesign. I suspect that the buckling occurred as a result of dynamic loads (car bouncing along the road) and not static ones.
Second, there is a small cross member (angle iron) near the rear of the car that is bolted to the aft ends of the transaxle support forks via a pair of small 1/8-inch-thick metal brackets (see photo). The cross member bowed up in the center (between the transaxle forks) — probably because the aft battery racks were pulling down on the ends of the cross member.
Third, there are a pair of diagonal braces that support the aft ends of the rear battery racks (already removed when the photos were taken). They run from the aft outboard ends of the two battery racks up to the tops of the rear shock towers. Both of these braces were snapped off at the shock towers.
I’ll need to give the redesign some pretty good thinking. I may also want to see if I can incorporate mounts for the seatbelts and seat positioners into the frame instead of just bolting the belts and positioners to the floor pans. In the meantime, I’ve got all of the VW chassis parts to recondition.
