Maintenance should be simple and on a routine basis. It is important to be proactive in order to keep you in the field, out of the shop and making money.
By Mikel Janitz
Power take-off (PTO) equipment maintenance keeps your vocational truck’s mobile power equipment running at peak performance. It will help end uses and operators to continue building our world and making a living. Scheduled maintenance, not just good maintenance, is needed to ensure that the mobile power system, pumps and PTO are running as trouble-free as possible.
The maintenance process can be broken down into manageable buckets. They are the initial bucket, mid-term, long term and system buckets; there is also a duty cycle phase to be considered. Any one and all of these require planning along with mobile system knowledge and a good understanding of the operational side of the equipment. Keep those ideas in mind as you plan out your tasks.
Safety First
Safety first at all times! Make sure you follow your company’s safety practices and procedures. Remove the keys from the ignition and store them in a safe place so the truck cannot be started accidently. Do not get up under a truck with the engine running or with the system engaged. Rotating components can be very dangerous. Read and follow any warning decals or precautions before starting any work. Also, ensure that the vehicle is not moving or able to move—use wheel chalks if need be. Lastly, it is a good practice to let the engine and tranny cool down so hot fluids, exhaust pipes or other parts do not burn you.
Maintenance should be conducted in the first few hours or days after starting up the system and engaging the PTO. Make a mental note of the noise coming from the truck before the installation and after. After the system and PTO have warmed up for a short period it should be shut down, let cool and inspected. How did it sound? A noisy power train can be a sign of high backlash, poor bolt torque, wrong gaskets or low fluids. If there is a lot of unusual noise this will need further investigation before driving the vehicle any distance. Lastly, after it is cold re-torque the PTO mounting hardware to Original Equipment Manufacture (OEM) specifications.
Timing Your Maintenance Reviews
The short and mid-term stage is the weekly or bi-weekly maintenance review. At this point the truck and system have been used quite a bit (approximately three months). The PTO and other parts have been heated up, cooled down and used for some time. By now it is fair to say the vehicle has experienced its normal duty cycle multiple times. This is the time to schedule an inspection. Look for leaks, check noise, examine fluid levels, look for loose items and ensure the hardware is torqued to spec. It is vital to listen to the system. How does it sound? Has anything changed from the initial stage? If anything has changed investigate it further and address it before it turns into something more costly. Noise can be the key to finding gear damage, which would need to be address ASAP. Some systems have indicator lights in the cab; if you are so equipped, use them. If they happen to be lit up unexpectedly, use them to do any troubleshooting per the OEM instructions. It could be as simple as a loose wire connection. This will also help you get more familiar with your set up and make future inspections go quicker.
Performing long-term maintenance is not difficult and is typically tied to regular vehicle OEM maintenance, or engine and transmission maintenance. The maintenance tech can consider the PTO an extension of the transmission. These are highly engineered products and very robust. When the fluids are checked on the engine and tranny, look at the PTO. The short list is: look for leaks, check to make sure no parts are loose, and verify hardware is properly torqued and so on. If anything needs to be repaired or replaced, now is a good time to address it. For example, if the tranny fluid is dirty you might change it. If fluid is low, fill it to its proper level. If there is a leak, consider replacing the appropriate seal or gaskets.
Sounds and Wiring
Also, listen for drive train sounds. Listen to hear if there are any notable changes. Is there noise? This can be a good time to check gear backlash. Verify the backlash is within acceptable tolerance. While checking the backlash take the time to look at the gears. Look for nicks, pitting and excessive wear on the teeth. If need be, you can remove the PTO from the tranny for a more detailed inspection. Based on what you find, repair, fix and replace as appropriate. Worn or pitted gears need to be replaced. A reputable OEM will have a kit to help do this. Note: if gears are being replaced you should inspect bearings. It is a good practice to change bearings and seals if you replace gears. Also remember to pack bearings with grease. One other thing to mention is wiring. Wires come loose. Wires can break and melt. Inspect your wiring for loose connections and melted wire and broken wire ties. Fix and replace as needed.
Duty Cycles
After a few months and the early stages of preventive maintenance are over, it is a good time to think about how to set up maintenance based on your duty cycle. There are two types of duty cycle, intermittent or continuous. More simply put, light work or heavy workloads. If a PTO is used less than five minutes at a time a couple times a day, it is considered intermittent. If the system is used more than five minutes in a 15-minute time span, it is called continuous duty.
A continuous duty system will likely require more inspections and maintenance than intermittent duty systems. So adjust your schedule accordingly based on the duty cycle. Just a short note here to highlight OEM vehicle maintenance. Anytime the vehicle is in for normal repair and maintenance—whether it be for tires, breaks, engine or chassis—take the time to add in PTO and mobile power system inspection. Sometimes things happen and anytime the vehicle is in the shop check PTO fluids, torque, seals and listen for odd noise. Then take the appropriate steps to fix anything you find. Sometimes it may be as simple as pulling the pump from the PTO cleaning off the spline and applying fresh grease to the shaft and PTO output.
Keep Maintenance on a Routine Basis
Maintenance should be simple and on a routine basis. Maintenance is designed to save you money in the long run. If it is not scheduled it will probably not get done until it breaks. It is understandable that maintenance can be carried out in short, medium and long-term intervals. It depends a lot on the duty cycle and the work environment in which the vehicle is used. Remember to use OEM-approved replacement parts whenever possible. It is also important to keep good records of the work performed. This helps with stocking the right parts to get you up and running again. It is important to be proactive—that keeps you in the field, out of the shop and making money building our world. | WA
Mikel Janitz is the OEM Applications Engineer for Bezares USA, a global leader in PTO design and engineering based in Houston, TX. Mikel lives in Tulsa, OK, but covers most of the U.S.’ mobile power industry vocations. He graduated from Oklahoma State University with a BS in Engineering and MS in Engineering Management and holds several patents. He can be reached at (918) 953-9062 or via e-mail at [email protected].