How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dan Your Own Question
Dan, Technician
Category: Construction and Road Equipment
Satisfied Customers: 5167
Experience:  17+ yrs. shop and field experience with all major brands of heavy equipment and trucks - 1995 WyoTech graduate.
Type Your Construction and Road Equipment Question Here...
Dan is online now
A new question is answered every 9 seconds

I have a Pc-40-5 serial#8840 that has swing problems. They

Customer Question

I have a Pc-40-5 serial#8840 that has swing problems. They start as a bad bearing in the gear noise and end with no swing. I have had the swing motor looked at three times with no problems found and took apart the swing gear not finding any problems. my question is actually questions, have you encountered anything similar and I cannot find a repair manual which would helpful with this old machine.
Submitted: 1 year ago.
Category: Construction and Road Equipment
Expert:  Dan replied 1 year ago.

Hi my name is***** will be glad to try to help. I worked as a tech for Komatsu in the past. It is better for me to start fresh as I can not be sure if something was overlooked when this was looked at and disassembled. Check the swing gearbox oil level and also the swing cavity grease to see if the grease is soupy from mixing with oil from a leaking pinion seal in the swing gearbox. If so the swing gearbox would be running dry and could bind and eventually fail internally. If that is ok check the pinion gear and swing bearing for chipped, broken teeth and also for play in the swing bearing (Raise machine with the bucket to see if there is play in the swing bearing between the car body and track frame. Check the return hydraulic filter for fine metal in case there is a potential swing motor failure occurring and producing metal into the system. Let me know I do not have the manual for your serial number break but I can help you with something close to give to some help with troubleshooting. Click here.

Related Construction and Road Equipment Questions