I installed a new final drive motor on the left hand side of a Kobelco SR80 excavator. The motor is a new aftermarket. All of the lines were hooked up the same way as the old one. Now when I push the lever forward the motor spins backwards, when I push the lever backward, the motor spins forward. All of the hydraulic lines are hard lines and are verified correct with the manual. Additionally, the hydraulic lines are so rigid, they can only be hooked up one way. Any help would be greatly appreciated. I have searched the forumns and could not find any existing information. Thank you.
in the manual does it say about drive motor timing? some drive motors need to be timed if yours has been timed wrong that would be the cause
Out of time.
Sounds like you got something backwards.
The manual does not say anything about timing the drive motor. I agree it does sound like something is backwards. The only thing I changed on the new one was the return port was on the bottom and I switched it to the top to match my old one. All of the hard lines had to go in the same place. The forward/reverse ports are different size than the forward/reverse ports.
Your gonna have to pull it again and turn the top casting where the ports are...
Welcome to HEF 08f250. :drinkup I have no idea what type of drive motor your machine uses, but if it's something like a radial piston or roller stator motor, as others have suggested, there's a timing plate inside the motor. Since it's a new aftermarket motor, I would suggest contacting the folks that you purchased it from and tell them what it's doing and that everything is hard pipe, no way to have lines switched, and see if they have any suggestions.
Is there a L/H and R/H motor for this machine ? Or is it 1 part number for both sides ?
There is one part number for both sides. You cannot turn the casting where the ports are. The L/R would make sense as the reverse line is on the top on both.
Wait a minute, Kobelco SR80? Never known a Kobelco SR model, Kobelco machines are typically SK (SK80). Would it be an SK80CS? Does it have a dash number, -1E, -2?
Yes a SK80CS.
I checked the parts catalog for a number of the SK80CS machines, and though I haven't checked all of them, I'm not seeing a left or right motor part number, just a single number for both sides. Given that it's a new aftermarket motor, if it were me, I'd be calling the people I purchased it from. I'd be reluctant to taking it apart and possibly voiding the warranty unless I had their blessing. And I have to ask this, is it certain no other changes have been made to the machine, such as work on the pilot valves for the drives or any work/repairs at the main control valve?
Absolutely no other work done at the main control valve. Both sides have the same part number- I have the parts manual.
Don't open the motor up, I don't think you can do anything in there to change rotation, looks like a standard piston setup to me. Swap the two control lines off the bottom of the left pilot controller under the foot pedal and carry on. As long as it travels at the same speed as the original on the other side, it should be good. I'm guessing the new aftermarket drive may just be different output rotation in the final, but they should have told you that if it is.
Sometimes you can buy the motors with opposite rotation. Perhaps the aftermarket supplier got some weird ones.
Unfortunately the pilot lines on the left side do not reach to be switched around. My only option was to swap pilot lines on the the right side to make them match.
Well, the other option, it looks like the lines to the top of the swivel joint are hoses, you could swap the two for the left motor, if you can identify them with the help of the parts book.
There is not enough line length to swap them at the swivel joint. Thanks for your help, I am wondering what the seller will say.
Can you post some photo's of both drive motors and indicate which are the forward and reverse lines on each motor?
Where did you buy the drive from? There is an aftermarket supplier selling a Comer unit that does this all the time. If you have that unit, you're going to encounter more problems than just backwards rotation. We stock direct replacements for this machine. Whatever you saved up front isn't going to be worth it in the long run. I'm curious as to what the supplier told you. I can help you straighten this out. Send me a PM with your contact info.
this is something we have seen with a number of Aftermarket drives. doesn't mean there is anything wrong with the drive just that the lines are hooked up the wrong way. There are 3 solutions to this, depending on how your main feed lines are set up. 1) if the hoses are flexible going into the drive just swap them over as this will send the motor in the opposite direction. 2) change over the controls at the main control valve in the same way. again this can only be done if there are flexible hoses going into the drive 3) finally you can change over the pilot lines in the control lever/pedal so that when you push forward on that side the pedal sends a signal to tell that track to move backwards and vice versa. one of these solutions should work for any machine. bear in mind that very few excavator drives are handed it is essentially 50/50 if this can happen on a new install with any aftermarket unit
I wanted to let you know what happened or what the problem was- it was a final drive that spun the wrong way. I ordered the original one from Woodland Fluid Power and the salesman assured me this was an Italian-made Comer unit. When I received the package- the final drive said Tong-Myung. It took over 5 hours with 2 guys and heavy rachet straps to get 3 hard hydraulic lines hooked up because the fitment was very different on the Tong-Myung. I ordered a OEM replacement made in Japan- that is the exact same as the other side. It took approximately 15 minutes to hook up the hydraulic lines on the new unit. Everything works as it should!
:thumbsup