Categorizing Parts Based on Expected Life

Did you know that the parts in a final drive can be divided into three groups based on their life expectancy?

Fast wearing, slower wearing, and long wearing – these are the three groupings that parts in your final drive will fall into based on how fast they wear and whether or not it’s considered feasible to repair them. Let’s start by taking a look at what the fast wearing parts are …

Fast Wearing Parts

Fast wearing parts are, as the name indicates, those that experience wear the fastest. They are not reusable, which means that it isn’t cost effective or feasible to try to repair them. This grouping includes seals, gaskets, and anti-friction bearings. When a seal fails, you know to replace it – not to try to repair it.

Slower Wearing Parts

Slower wearing parts, on the other hand, might be reusable. This group of parts includes shafts, gears, plates, and discs. There are a variety of repairs that can be performed on these parts to recondition them to OEM specifications, but keep in mind that some damage and wear cannot be repaired. For example, lapping can be used to restore the flatness of a damaged surface like a valve plate.

Long Wearing Parts

The long wearing parts were designed so that they would not have to be replaced, and aren’t subject to the same loading conditions as the parts that wear out. These types of parts include the housings, carriers, and hubs. It takes a fairly catastrophic failure to wipe out a final drive hub … and if they hub got destroyed, it’s likely the rest of the drive will be totaled, too.

Conclusion

Not all parts on a final drive were designed to be repaired. Some of them, like seals and gaskets, it makes sense to replace. Shafts and plates are slower wear parts that were designed to last longer. Parts like the hub, housings, and carriers were designed to last indefinitely, and rarely need replacement or repair.