1974 Corvette Project: Restoring The Frame

If You Want It Done Right, A Frame-Off Restoration Is The Only Way To Go

Andy Bolig Aug 1, 2001 0 Comment(s)

Step By Step

There are rods and braces that hold the front end of the car to the frame. The core support was so rotted that all we needed to do was cut the plumbing strap that held the radiator in place, remove the panel under the nose, and pull the bolts from the front of the frame horns to prepare the nose for removal.

When removing the frame-mount bolts, you might want to soak them in penetrating fluid before you attempt to loosen them. Doing so will lessen the chance of stripping the head or twisting the captured nut inside.

If they won’t come out, grind off the head and use pliers to remove them once the body is out of the way.

There are two mounts in the rear wheelwell opening. The front mount is behind the access cover where the trailing arm connects to the frame, and the rear is out in the open in the back of the wheelwell.

You can see that the body-mount rubber is totally disintegrated, and definitely needs replacing.

We had to remove the battery ground and the antenna ground strap to separate the body from the frame.

Also, the brake lines and steering had to be disconnected, along with the shift cable and speedometer.

Once we made sure everything necessary was disconnected, we lifted the body with the help of a lift. Go slowly, and make sure that nothing is pulling because, when using a lift like this, you won’t notice it pulling until it’s dangling about four feet off the ground. These lifts are made for lifting a whole car, so stretching a cable or wire another 4 feet is nothing for them.

The ’73 and ’74 bumper mounts are different from other shark bumper mounts.

The ’73 front, and both front and rear on the ’74, were cast with a sliding peg that acted as an absorber.

There was a clip that would slide down the pin as it absorbed the impact. This is how you can assess crash damage on a ’73 or a ’74. If the pin has scrape marks, the car was hit hard enough to compress the absorber.

We removed the driveshaft, engine, and transmission. These parts will be rebuilt or replaced before they go back in the frame.

This car was from Georgia and had a substantial coating of mud and clay mixed in with the grease. Ron pressure-washed the entire frame to get it as clean as possible. We even found some loose change buried in grease on the transmission crossmember.

This is a sure sign of a rear suspension that needs rebuilding! The last time this car was aligned, they couldn’t get enough adjustment so they just BENT THE TRAILING ARMS! If you see this on a car you plan to buy, run away—or plan on sinking a lot of money and time into the rear end.

Consumable parts like the shocks can be thrown away.

However, many others, such as the brake calipers, should be kept and used as a core-return for the new ones.

We’ll be running all new brake lines and fuel lines. It would be wise to keep all of the old lines until you get the new ones installed so you know how they were routed. At least take pictures for reference.

Ron removed the entire steering assembly. He’ll rebuild it with new joints and ends, along with rebuilding the steering box, before installing it in the new frame.

Removing the control arms and spindles takes a bit of care. Even though the body is removed from the frame, the springs still have significant pressure on them. Ron uses a chain as insurance in case the spring comes out unexpectedly.

Another good reason for doing a frame-off restoration is to catch other people’s “fixes.” This wad of silicone was under the fuel tank to “repair” a leak. This is one extra part we won’t reinstall.

The spring will be replaced with a fiberglass one. The owner wants to drive this car, so why not get the best ride possible?

Next, Ron removed the driveshafts...

...and differential.

The trailing arms were the last things to be removed.

These weren’t too rusted, so we’ll rebuild them. There are several Corvette Fever advertisers who can supply you with new trailing arms if yours are not repairable.

With the frame totally stripped, we could check for rust. Surprisingly, the frame was very solid. We’ll be sending it to Revivation in Wauchula, Florida, to get dipped, so if there is any rust on the frame at all it will be removed. When we get the frame back, there will be only metal. All rust and scale is removed. We’ll also send the control arms, crossmember, and any other metal pieces we want cleaned of rust.

Frame rot. Everyone looks for it when they’re interested in buying a ’68-’82 Corvette, but no one wants to find it on one they already own. There’s only one way to be sure there’s absolutely no rust on the endoskeleton of your shark, and that’s to do a frame-off restoration. Among the many benefits of this type of restoration are guaranteed rust removal, rebuilding the necessary systems as you reassemble, and the assurance that even what you can’t see is done right.

The owner of this ’74 Corvette wanted it completely restored, which brings us to some of the downsides of doing a frame-off restoration. She will have much more money invested in the car than what she could ever sell it for. As you go deeper into a restoration, you’ll certainly find more and more items that need to be replaced. She had owned this car since she was 16, so the sentimental value of the car far exceeded any monetary concerns. She wanted it done right, so a frame-off restoration was the only way to go.

When we finished this story, the frame was being stripped, and when we get it back it will look like new metal. Any stampings will not be damaged, and we won’t have to worry about any sand residue coming out of the cracks and crevices when we do the paintwork. Our next installment will cover treating the frame and installing the new components necessary to make this a top-notch restoration. Wait and see!

Follow along as Ron at the Corvette Clinic shows us what it takes to de-bone a shark.

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