In this Shop Talk Blog post, we are going to talk about how to maintain the final drives on your Bobcat E32 and E35. Regular preventative maintenance will greatly extend the life of your final drive motor, and paying attention to details like case drain filters can save you thousands of dollars in downtime and repairs.
Bobcat E32 and E35 Final Drives
The Bobcat E32 and E35 are R-series mini-excavators in the 3- to 4-ton weight class. They are made by Bobcat, the only American manufacturer of compact excavators. Relatively speaking, they're still fairly new on the market. They have quite a few awesome features, including a one which affects the final drive motors: both the E32 and E35 have auto shift, which switches between high speed and low speed travel automatically.
Gear Oil
For a new machine, Bobcat recommends checking the gear oil level once during the first 50 hours and then every 250 hours after that. It should be completely replaced every 1,000 hours or every year. Note that Bobcat also recommends changing out the gear oil once after the first 50 hours on a new machine. The recommended gear oil is SAE 90W. This is basic maintenance, and failure to follow through with these simple steps can void warranties.
If you let the gear oil get too low or fail to change it regularly, you will start to see damage to the gears and bearings in the gear hub. If you suspect you have a leak in the gear hub, get the seals replaced as soon as you can or you can destroy the gear hub. The picture below shows what can happen when a seal fails and dirt can get inside your final drive motor while the gear oil leaks out.
Hydraulic Filters
Both the Bobcat E35 and Bobcat E32 have case drain filters that must be changed regularly. Failure to do so can destroy an otherwise good final drive. The case drain filter should be replaced once during the first 50 hours and then every 500 hours after that (at the same time you replace the hydraulic filter and reservoir breather). All filters are very important in a hydraulic system, but failure to take care of the case drain filter will total a final drive. Many of the final drive motor repairs we perform can be traced back to a neglected case drain filter much like the one shown.
In the Bobcat E35, the case drain filter is located below the floor plate. That means you’ll need to remove the floor mat and the floor plate in order to access it. The filter housing looks like an aluminum canister that is about 1 ¼" in diameter and between 3" and 3 ½" long. Remove the filter from the drain lines and be sure to plug the drain lines to avoid losing hydraulic fluid. To access the filter element, simply unscrew the hex nut. It contains a tapered sintered-bronze filter element and two springs holding the filter element in place. If the filter is no longer a bronze color, it needs to be replaced. After you remove the case drain filter housing, clean the housing where the filter gasket comes into contact with it. Then put some hydraulic fluid on the gasket itself, replace the filter and springs, then hand-tighten the hex nut.
Conclusion
The Bobcat E23 and E35 mini-excavators are excellent machines. Simple maintenance tasks like those outlined here can maximum the life of the final drive motors on these machines and save you a great deal of money in repairs and replacements. Don’t neglect your final drive motors, even when you have a brand new machine!
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.
