Seal Cross-Reference List

by Tony OldhandUpdated March 16, 2018
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All engines and machinery that use oil or liquids have seals. Seals usually fit around a shaft, and allow the shaft to turn freely but block the oil from leaking out. Thousands of seals may fit a particular shaft size or housing size. For this reason, hundreds of seal manufacturers provide extensive cross-reference lists, so you can find the exact replacement seal to fit the application.

Determining Size

You have to determine the size of the shaft and the size of the housing the seal fits into if the old seal is unavailable. In essence, you have to determine the seal's inside and outside diameter. Obtain a machinist's micrometer and measure the shaft. If you do not know how to use a micrometer, take the shaft to a machine shop where they can measure the diameter for you. After, you must measure the diameter of the hole in the housing. This is the outside diameter of the seal. Again, a machine shop can do this for you.

Determining Shape

Look at your old seal if its available. Some seals have a single inner lip, while some may have two or even three. A inner lip is the soft rubber part that rubs up against the shaft. Also, look at the outside metal ring. Some seals have a thin metal lip to catch on the housing, while others are smooth. Finally, wash the seal with dish soap and water. Inspect it closely for a manufacturer's name and part number. If you can find this, cross-referencing a seal will be a lot easier.

Determining Materials

You have to determine the material the original seal was made out of. Some seals are made out of materials that withstand acids or withstand high temperatures. Investigate the liquid the seal was blocking and its normal operating temperature. Cross-reference lists will specify the material the new seals are made out of and what liquids the seal can and cannot be used on.

Reading The Charts

All seal manufacturers provide extensive cross-reference lists for their seals. This is so you can find a replacement seal if the original manufacturer went out of business or the seal is no longer manufactured. Every manufacturer approaches it differently. For example, the KOK Seal Company provides a reference number, usually found on the old seal. The Timken Corporation wants you to provide a specific part number or provide a year and model for a vehicle. The GBSA Company provides a cross-reference list for other manufacturers. If you investigate the seal cross-reference lists provided by the manufacturers, eventually you will find the seal you need.

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