By Lance Plahn
Whilst working on your VW project, do you ever feel like a pioneer? That is breaking new ground. I know I do sometimes, yet you know someone has done the job before. So you contact some people in the VW trade who advise they have heard about it but never seen or done it themselves. After reading volumes of material there was nothing relevant written on the subject.
This is a story on one of those adventures, however it is not a tech story on how to do it, more a guide on how I approached it. The challenges that arose requiring a solution. A story like this requires lots of good detailed step by step photo's to help make it successful.
My son and I are rebuilding a Kalita (similar to a Manx). It's mounted on a 1200 floor pan. You know , king and link pins with motion retarders, (ideal for creek crossings) and a 1200 gear box with swing axles. We wanted ball joints and discs up front and IRS at the rear for better off- road traction. The obvious choice is a 76 pan, but they are very scarce, probably due to the numbers sold. The next choice was a 1500 auto pan, then weld in a clutch tube, however this required 90% of our project funds. So a very cheap super bug was acquired, rendering a 1600T/P and IRS rear end complete with gear box and suspension. All I had to do was weld on a 1500 bulk head, which I had acquired some time ago. A friend had to put another pan under his 1500 because the horn cracked nearly all the way around on the driver's side under the axle. I have seen the six volt type three's do the same.
The first thing was to remove the bulk head from the 1500 floor pan. This was done with the aid of an electric drill, to drill out the spot welds and an angle grinder, to cut the welded sections. Set aside a few hours. The spot welds were across the top of the floor pan, forward of the body mounting cross over. The next row is under the pan, rear of the body cross over or more precise, the raised section. I cut the body mounting cross over off and cut the tunnel in half in the middle of this cross over, giving plenty of tunnel to play with later on.
Next was to remove the super bug section from the pan. This took much longer as the super bug is considerably different in construction. But never the less, same principals. This time the tunnel was cut a few millimetres forward of where the body mounting cross over is welded to the tunnel. At this point the tunnel dips down then.
Now the challenges arise, welding the 1500 bulk head to the super bug pan. Firstly the distance between the body mounting bolts is further apart on the super bug than the 1500. Also the 1500 bulk head is narrower than the super bug section. No problems, remove the whole anti crush spacers from the super bug pan, moving them into line up with the holes in the 1500 pan. Then when the 1500 bulk head is welded in place, trim up the super bug pan to suit, drill new holes and fill the old ones. The 1500 tunnel fits into the super bug tunnel, enabling welding of the two tunnels in an overlap situation as opposed to a butt weld. The super bug body mounting cross over is approximately 15 millimetres wider than the earlier models. The next challenge is the 1500 pan is flat under the tunnel and bulk head, where as the super bug drops just before the bulk head and continues to the front. So when the 1500 bulk head is mated to the super bug pan, there is a section protruding down, like a scoop. So this corresponding section was cut from the super bug pan and grafted onto the 1500 bulk head and continuing back, mating with the dropped section, thus giving extra support under the rejoined section. The fuel hose refitted without any difficulty which is a bonus. For best results, weld in the 1500 bulk head with a mig welder. Of course much attention is directed to ensuring the whole thing is welded in square, continuing measuring the diagonals.