1970 Camaro Subframe Bushings: Choosing Body Mount Parts

Define the job the product must do

The second-generation Camaro arrived partway through the 1970 model year and is often called the 1970½. It uses a separate front subframe that carries the engine, front suspension and steering. That subframe is bolted to the body shell through insulated mounts. The bushings keep driveline and road vibration out of the cabin and locate the subframe relative to the body. Together with any shims, they also help set front sheet metal alignment. Worn mounts typically show up as clunks over bumps, more vibration through the floor, changing gaps between fender and door, or a subframe that sits visibly off-center.

Before shopping, decide what the car is for. A numbers-matching restoration headed for judging needs parts that look and behave like original rubber. A driver that sees regular street miles benefits most from comfort and quiet. A car built for autocross or track days may justify firmer material in exchange for more noise. Be realistic about practical constraints too. Can you safely raise the body? Are the bolts and body nuts likely seized? Will the job coincide with other front-end work, such as subframe refinishing or a suspension rebuild?

Check compatibility

Aftermarket kits for this car are commonly cataloged for the 1970 through 1981 F-body, and often for the Firebird as well. Treat that listing as a starting point, not proof of fit. Confirm that the listing covers your model year and body. Then compare the kit contents with the positions you plan to service. The subframe-to-body mounts are one set. The radiator core support cushions are a separate set of bushings, and some kits include them while others do not.

Fit is decided by a few specific interfaces: bushing height and diameter, the shape of the upper and lower halves, the inner sleeve size for the bolt, and the retainer washers. Hardware matters as much as the cushions. Some kits include new bolts and retainers, while others supply only the bushings. Also inspect the cage nuts captured in the body mounting pads. A nut that spins or has torn loose must be repaired from inside the floor or rocker area before new mounts can be tightened. Take torque values and tightening sequence from the factory service manual or the kit maker's instructions, not from a generic figure.

Previous work can change what fits. If the service history mentions a replacement subframe, added subframe connectors or an earlier solid-mount conversion, measure the existing parts and pads before ordering. Modified mounting surfaces or extra hardware may not match a standard kit.

Features that affect the choice

Three materials dominate. Rubber follows the factory approach. It gives the best isolation, the quietest ride and the correct appearance for a restoration, but it compresses over time and degrades with oil exposure. Polyurethane is firmer, resists oil and holds its shape longer. It gives a more connected feel with less subframe movement under load, but it transmits more vibration and can squeak if not lubricated as the maker directs. Solid aluminum or steel mounts remove nearly all movement. They also send noise, vibration and harshness straight into the body, so they generally suit dedicated performance cars rather than street drivers.

Separate useful information from marketing labels. A stated hardness rating on a polyurethane kit is useful because it describes a measurable property. Terms such as heavy duty or performance grade tell you nothing on their own. Look for details you can check: the material, the hardness if listed, whether the inner sleeves are steel, whether bolts and washers are included, and whether the design uses separate upper and lower cushions. For judged cars, also check the finish and shape of washers and bolts, since visible hardware is part of correctness.

Shims deserve attention. Many cars have alignment shims between the body and one or more mounts to position the body on the subframe. Before taking anything apart, record and photograph the number and location of shims at each mount. New bushings that differ in height from the old ones may require re-shimming to restore hood, fender and door gaps. Some kits include shims and others do not, so plan for that.

Limitations and ownership costs

Most of the cost is labor, not parts. The body is usually lifted off the subframe in stages after the mounts are loosened. Anything still connecting the two needs attention, including the steering shaft, radiator hoses and fan shroud, brake lines, wiring, exhaust and shift linkage. Support the body on suitable stands and blocks, never on a jack alone. Budget for consumables as well: penetrating oil, replacement bolts if the originals are corroded, a thread chaser, rust treatment and paint for the pads, and the lubricant specified for polyurethane.

New bushings cannot fix structural problems. A rusted floor mounting pad, a damaged core support or a bent or cracked subframe will still cause misalignment and noise. Inspect those areas first, because repairing them can cost far more than the bushings. If suspension or steering parts are disturbed during the job, have the front end aligned afterward. Also confirm that the steering shaft and linkages do not bind once the body is back down.

No universal replacement interval applies to these parts. Their condition depends on age, oil leaks, storage and operating conditions. Build a quick check into your maintenance schedule whenever the car is on a lift. Look for cracking, rubber squeezed out from under the washers, uneven gaps and loose bolts. Polyurethane mounts may need relubrication if they start to squeak.

Build a practical shortlist

Narrow the choices with a checklist rather than a ranking. For each candidate kit, confirm the following. The listed fitment includes your 1970 Camaro and body. The included positions match the mounts you are replacing. The material suits your intended use. Bolts, retainers and washers are included, or you know what to buy separately. Shims are included or available. Instructions give torque values and sequence. The return terms cover parts that do not fit your vehicle configuration.

Then weigh the remaining kits against your priorities. For a judged restoration, correct-appearance rubber and hardware come first. For a regular driver, rubber or a moderate polyurethane balances comfort and longevity. For a dedicated performance car, firmer polyurethane or solid mounts make sense if you accept the added noise. Before ordering, inspect the mounting pads and cage nuts so your budget covers any repairs. Afterward, record the parts used and the shim positions in the car's maintenance file.