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The Most Pervasive Problems in Final Drive Motor Maintenance

There are some final drive motor maintenance failures that we encounter over and over, and we’d like to make sure you are aware of them so they don’t happen to you. Are you guilt of any of these?

The Most Pervasive Problems in Final Drive Motor Maintenance

Here are some additional blog posts that might be helpful ...

Neglecting the Gear Oil

You should check the gear oil level about once every 100 hours of operation, and change the oil out at least once a year. We get far too many final drive motors where the oil has not been changed out in ages.

How can we tell? We open up the gear hub only discover gear oil that has formed a sludge with a pudding-like consistency and a horrific smell. Gear oil in that condition is going to do far more harm than good. It will shorten the life of the components in the planetary gear set that converts speed to torque.

Ignoring Leaks

If you know your final drive is leaking, then you need to get the face seal replaced. Failure to maintain the integrity seals by replacing them when they have worn out can lead to a host of problems, including these:

  • Water, dirt, mud, sand, and other types of grit can get into your final drive, shortening the lifespan of critical components and running up more and more expensive repair bills the longer you ignore the problem
  • Contaminated hydraulic fluid that can cause damage in other parts of your hydraulic system
  • Loss of gear oil, leading to major problems in the gear hub
  • What gear oil is left has been turned into a gritty sludge that can tear up the surfaces of gears and bearings within your gear hub
  • Eventually, you can end up with a totaled final drive motor that cannot be repaired




Don’t ignore leaks. Checking for leaks and addressing them quickly should be a regular part of your final drive maintenance.

Forgetting to Check the Case Drain Filter

First, let’s add a disclaimer: not all hydraulic machines have a case drain filter. That said, Bobcat machines usually do. The case drain filter removes contaminants from the excess hydraulic fluid (which lubricates components within the planetary side) as it leaves the final drive motor to return to the hydraulic tank.



If this filter gets clogged, there is no bypass. The result is a huge buildup of pressure within your final drive and a cascade of failures that will total final drive motor. And this is a shame! Thousands of dollars of damage that could be avoided by changing out a relatively inexpensive filter -- just like you see in the image above, where piston shoes were blown off by the pressure and then ground up in a bearing. If your machine has a case drain filter, make checking that case drain filter a regular part of your maintenance activities.


If you change your gear oil on schedule, check for leaks regularly and check them regularly, and check your case drain filter (if you have one), then you will go far towards having a final drive that will last a long time.

Texas Final Drive is your partner in providing new or remanufactured final drive hydraulic motors from a single mini-excavator to a fleet of heavy equipment. Call today so we can find the right final drive or hydraulic component for you, or check out our online store to find your O.E.M. manufacturer brand motor now. 

Visit the Final Drive Shop for all of your hydraulic final drive motor needs!

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Topics: Final Drive Maintenance, Gear oil, Leaks, Preventative Maintenance, Case Drain Filters, Final Drive Problem

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