There was a time when repairing extensive rust damage on a Tri-Five Chevy or a GMC cab meant tracking down a good or at least better example of the necessary sheetmetal and then carefully cutting it out. From here the next step was to figure out how to gracefully graft it back onto the truck. Back in the '70s, when these trucks were 20 or so years old, it took a real metalman and a fair amount of luck to pull the job off successfully. Flash forward another 10 years or so and the pool of good replacement used tin has diminished considerably, and time has taken its toll on the number of good metalmen around.
That said, it would seem things in the 21st century should be pretty bleak, but that's not the case. To the contrary, there have been some major breakthroughs in the availability of good reproduction restoration parts and welding technology that make it easier for a DIYer to do a professional welding job. Notice we said restoration parts, not crash repair. Crash parts are usually cheap junk that fits poorly and devalues a truck, while restoration parts are intended to be undetectable from the original. The restoration parts Carmen Porca installed on his '57 Chevy big- window were sourced from Tucker's Classic Pickup Parts in Las Vegas, Nevada.
Installing the new parts started out much in the same way as the old days. The rusted pieces had to be carefully cut out of his cab. But before this could happen, it was absolutely necessary to weld a flat support strap into the doorjamb above the step (the running board in the cab) to eliminate any possibility of the cab springing (distorting) out of its original shape. Trust us, if you continued on page 66 fail to properly reinforce the cab and it springs out of shape, you will have a nightmare on your hands trying to pull it back into place.
Once the cab is reinforced correctly, the next step is to carefully cut out the rusted parts. The following steps involve determining the right sequence in which to install and weld in the Tucker's parts. This was done through a mock-up process, then tack welding them into place. The final welding was not completed until everything was double-checked for fit. As with any improvements to your truck, the key to success is patience and proper planning. So there you have it-take your time, think it out, and have fun!
Few things in life can be...
Few things in life can be guaranteed. One thing that can is a 50-yearold Chevy cab's terminal rust. Thanks to Tucker's Classic Pickup Parts, the restoration parts needed to fix it are just a phone call away.
There are several ways to...
There are several ways to cut out the rusted metal. One of them is a cutoff wheel on a body grinder.
Here Carmen uses a pneumatic...
Here Carmen uses a pneumatic die grinder with a 4-inch cutoff wheel to get into tighter spots.
To handle the factory spot...
To handle the factory spot welds, Carmen uses an electric drill with a drill bit large enough to cut out the spot weld.
With the rusted piece cut...
With the rusted piece cut out and the spot welds drilled, it's time to remove it from the cab.
Here's how the running board...
Here's how the running board (cab step) appeared after it was precisely cut and removed.
Here's the new replacement...
Here's the new replacement part from Tucker's-ain't it purty?
An extremely rusted hinge...
An extremely rusted hinge pocket is typical for a Tri-Five Chevy.
The first step to cutting...
The first step to cutting out and removing the hinge pocket is to carefully measure off and mark where the cuts should be made.
The next step after cutting...
The next step after cutting the old piece off is to put the new replacement part into position and retain it with Vise- Grips.
Here's how the hinge pocket...
Here's how the hinge pocket should look.
Here the new hinge pocket...
Here the new hinge pocket is held into place and the area to be cut out is marked with a Sharpie.
Notice Carmen marked the needed...
Notice Carmen marked the needed dimensions on the cab in plain view with a Sharpie. Also notice the new hinge pocket is tacked into place where the spot welds were.
Once Carmen is absolutely...
Once Carmen is absolutely sure the piece is exactly where it should be, he welds it in completely. Notice the long welding beads.
Observe how the Tucker's replacement...
Observe how the Tucker's replacement is shaped exactly like the original it replaced.
Here's how the part looks...
Here's how the part looks after Carmen welded it in. Notice the hinge is bolted in.
A China marker (grease pencil)...
A China marker (grease pencil) works well to clearly mark the new parts.
Notice Carmen used a little...
Notice Carmen used a little extra piece of tin to fill in an area that wasn't cut right. Anyone can make a mistake; it's knowing how to fix it that makes all the difference.
The front and rear pieces...
The front and rear pieces had to be placed and welded before the step could be welded in.
Here the step has been welded...
Here the step has been welded in. Notice Vise-Grips still keep the parts aligned.
Any adjustments that needed...
Any adjustments that needed to be made were done before moving on to the next step. Here a bottle-jack trues this area.
Here again a China marker...
Here again a China marker identifies an area to be cut.
Notice the bodylines are in...
Notice the bodylines are in perfect alignment.
Carmen kept his measuring...
Carmen kept his measuring tape close at hand to doublecheck dimensions.
It might sound like a good...
It might sound like a good idea, but using a factory illustration can be overwhelming. Forget about it and physically move the parts to determine where they fit.
Here's the hinge pocket in...
Here's the hinge pocket in place before the outer tin was welded on.
Now the outer tin has been...
Now the outer tin has been welded on. Notice the hinge bolt is tightened down.
If everything goes right with...
If everything goes right with your project, it will look like this. If not, you might want to take a little nap before you start over...and some vitamins, don't forget to take vitamins.