Seals Can Be Interchangeable

Need to replace an OEM seal? You might be able to do so with a generic equivalent

Occasionally, OEM seals may be replaced by generic equivalents available from your local auto parts store or neighborhood bearing supply shop.

All seal manufacturers publish master interchange catalogs, which cross-reference the OEM part number to the seal manufacturer’s number and match seals by size. To find the correct seal, you need to know the old seal’s part number or dimensions and its color, which indicates what material the seal is made from.

The part number should be stamped on the seal's inner or outer face as well as the manufacturer and seal dimensions.Photography by Mark Zimmerman

Stamped into the seal’s inner or outer face should be the OEM part number, manufacturer’s name and the seal’s dimensions. If the numbers aren’t there, measure the seal’s outer dimensions and its width. Because a worn seal’s inside diameter is difficult to measure and varies with the seal’s design, it’s more accurate to measure the outer dimension of the shaft the seal fits over to find the seal’s I.D. Once you have the seal’s nomenclature, you can have that old grouch at the bearing house look up its equivalent.

But not all seals are interchangeable. If the seal is oddly dimensioned or intended for some special application, the OEM may be your only source. However, things like wheel-bearing seals, countershaft and shift shaft seals often have more than one application and as such are commonly available.