Oil & Grease Seals in Brass-Era Cars

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MochetVelo
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Oil & Grease Seals in Brass-Era Cars

Post by MochetVelo » Sun Nov 17, 2013 3:53 pm

Seals contain liquids like oil, grease and coolant. Early automobiles used felt and leather seals primarily. Natural rubber is not resistant to petroleum, and will quickly degrade. The early seals worked, but had a limited lifespan and were subject to deformation and wear. A differential located on the rear ("live") axle contains thick oil or grease. Axle seals help prevent this oil from traveling out the hollow axle tubes and into the brakes. I say "help" because the oil often finds its way out to soak the brake pads. Here is a felt inner-axle seal on a 1911 Hupmobile:
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This seal is no more than a flat piece of heavy felt sandwiched between two steel plates. Pressure compresses the felt further, and the seal rubs on the axle... for a while. The oil-soaked brakes in this car showed the seal had failed. A visit to a bearing & seal dealer produced a compatible modern seal, in this case 2-1/8" O.D. X 1-1/8" I.D. Here we see the new seal in place. Note the bits of soft plastic around the edges. This helps to make an oil-tight fit:
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This seal was thinner in profile than the original, but will do the job well. Modern rubber compounds like butyl and polyurethane are unaffected by oil and are more flexible than the old leather and felt style. Here is a close-up of how the "lip" seal (as these are called) work:
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The tiny coil spring keeps the seal in contact with the shaft. The leather seals work the same way. Note that the "lip" (spring) side faces the liquid you wish to contain. In this case, it faces inward toward the differential. An odd size seal opening may require a bushing to hold a modern seal. This can be made on the lathe. There are many styles of seal for hundreds of uses, but the single-lip seal is the type generally used in antique cars. The felt-type seals are still sold, but the rubber type perform better in most cases. A "seal driver" set can be purchased at Sears or Harbor Freight to tap in new seals. You can also use a wood dowel, PVC pipe or similar tool. Tap only on the outer ring of the seal, never around the flexible part. There are various hook-shaped tools made to remove seals, but you can also drill a hole in the seal ring and insert a sheet metal screw to pull it with a claw hammer or pliers. Do not re-use old seals.

Phil

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