I noticed some oil leaking from the cone seal on on one of my final drives so i checked the oil level and its full (to the brim not just the fill plug) and seems to be under very slight pressure. I'm guessing the shaft seal on the motor has gone filling the gearbox with hydraulic oil and that the case drain has enough pressure to make the cone seal leak. I had a look at the parts manual and it looks like changing the motor shaft seal is simply a matter of unbolting the motor from the gearbox, slipping it out then replacing the seal which is retained by a circlip. Am I missing anything? By the way the machines a Hitachi Ex270-5.
This is most likely a sign that the drive motor has excessive leakage and needs to be repaired/replaced. You could try a seal and see but the odds are you will have to address a drive motor problem soon. How many hours are on the machine?
It's got 12000 hours so a tired motor wouldn't be a suprise. Would the way to check the motor condition be with a pressure gauge on the case or case drain line near the motor?
A common thing on EX270-5. The motor shaft bearing races wear into the case and allows the shaft to move outwardly slowly allowing case drain oil into the gear case. I have changed the case and reused the rest with great results. But not with 12000 hrs on the components. I also reset the bearing rolling torque. Keep in mind the other side if not leaking is most likely soon to have the same symptoms. This usually is not enough pressure (case drain pressure) to blow the duo-cone. Once again 12000 hrs those seals are worn too. Doing a case drain test on the motor would be the best way to tell what condition it is in. At 12000 hrs they most likely have been changed. Unless you are the original owner.
I agree with KenAl. I would check the case drain and if it shows excessive leakage I would pull both drive motors off and have them repaired. It would be a good idea to reseal the rotary manifold as well.
I just finished that little chore on my 330l, l caught it before it blew the seals in the final. On mine that shaft seal cannot just be replaced, its the first seal to go in, an the last to come out. I have yet to reseal the rotary manifold on my cat, I have done it on a 792 deere I used to own, about the same I would figure.
To check the case drain you should open the cap on the hydraulic tank and drain all the pressure off. Take the drain hose off the motor and cap it. Put a short hose on the motor drain and put it in a bucket. Block the track with a pin or the bucket and run the motor over relief. If the motor is shot the hose will probably try to leave the bucket in a hurry. If you just get a dribble you are probably OK. Keep in mind the seal could still be bad and the case drain not be excessive. Good Luck!
Thanks gents... I will check case drain and see what I find.
Fhofferaou17 I have a ex60 with leak between sprocket and motor do i have to drop the track to repair.
Yes you do
John do you have any experience with cat 330L drive motors. Little Z in Louisiana
I've not had to work on those. They should act the same as any hydraulic motor.