1979 Chevy Corvette - Part 6: Putting the Suspension Parts Together

With the suspension safe, sound, and ready to roll, the engine is next

Chris Petris Jan 28, 2005 0 Comment(s)
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This is the key to correct bolt torque and proper seating of components.All threads should have a tap run through them whether they have beenpowdercoated, painted, or just cleaned up. The bushing area (gray areabelow tap) has been cleaned with a wire brush to ease bushing-sleeveinstallation. An application of grease to this area preventsbushing-sleeve corrosion to the shaft. Corrosion between the bushingsleeve and shaft makes removing the bushing difficult.

The front suspension parts are back from the powdercoating shop and theylook great. All parts from Corvette Central are here and ready forassembly.

When the suspension parts came back, we realized we should have lookedcloser at the slag left behind on the front lower control arms. Thewelding slag was powdercoated over and will have to stay. Slag is abyproduct of welding, and red-hot pieces stick to the metal surface.Sandblasting or bead-blasting pieces typically removes it, although achisel is needed for stubborn pieces. Having flawed parts or pieces isunsettling, so we took extra time to remove slag from the front framesection before painting.

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This is the correct way to assemble urethane control-arm bushings. Pushthe outer sleeve into the control arm first. Then push the urethanebushing into the outer sleeve; apply silicone lube to ease installation.The inner sleeve should rotate on the urethane bushing, so a goodcoating of silicone lube should be applied to the outer part of thesleeve and a good coating of chassis grease applied to the inner portionof the sleeve to prevent corrosion.

We've invested a little over $300 in sandblasting and durablepowdercoating of the front and rear suspension and steering components.It was well worth the investment, even if we have to look at tiny bitsof welding slag. In addition to the cost of materials, it can take hoursto remove and prepare components for painting, so the cost of sendingthe work out is comparable. Powdercoating doesn't protect fromultraviolet rays, which isn't an issue under the car.

One problem we encountered was loose components on taper-fit areas suchas ball-joint studs in the spindle when powdercoat is left in place. Thepowdercoat is tough, but if there is any movement it will break out ofthe tapered hole, resulting in a loose fit. Most powdercoat facilitiesmask these areas if they're asked to. The threaded holes should have atap run through the threads to remove any powdercoat that was leftbehind.

We put the same coat of PPG DP90 black urethane primer on the frontframe section as we did on the rear. The primer has a semigloss finishthat was achieved by adding thinner to the urethane mix. We put a coatof paint on all of the pieces to prevent corrosion.

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When using urethane bushings, all control-arm-bushing retaining boltsshould have new lock washers and Loctite thread locker placed on thethreads. If the retaining bolts come loose, the control arm bushing willcome out. If the bushing comes out of the control arm, the arm can comeoff the control-arm shaft, which causes loss of steering control.Urethane bushing equipped control-arm-shaft bolts can be torquedanytime. Rubber bushings should be torqued at ride height.

The front suspension bolts were bead-blasted and dipped in DP90 urethanefor protection. We replaced all the Stover lock nuts and applied greaseto the threads during assembly. Stover lock nuts are crimped on one sideto grasp the threads, and they lose retention strength after removal andreplacement.

It's a good idea to replace the front springs to keep the car level andmake the installation easier. The replacement springs are shorter, andinstallation into the upper spring pocket is easy. It's also smart touse coated springs to prevent corrosion.

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Whether you're using factory upper control arms or aftermarket controlarms, the upper ball joint should be positioned toward the rear of thecar. The centerline shows the offset of the upper ball joint from centerto allow positive caster. The upper lines show the offset of the shaftso additional camber will be available during alignment. For propercamber alignment, remember to install the shaft with the offset to theoutside of the car.

If you use factory-length springs, place the spring into the upperpocket, then push it into the lower spring pocket. Be careful when youpush the spring into position--you can easily pinch a finger. If thelower control arm is raised 3-4 inches from its lowest position, thespring can be pushed into position with two stiff prybars and stay thereas the control arm is lifted.

A spring compressor can be used to install the spring, but it can bedifficult to remove the compressor once the spring is in place. We don'tuse one for this reason, but it may be necessary your first time. Youmay have to put the spring in a few times to figure out the compressor.Rental spring compressors are available at most auto parts supplystores. When used properly, spring compressors are safe, but don't tryany shortcuts.




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