Cat 315c, CJC02798. 8300 hours. The swing drive gear has been leaking oil, toward the end of last season it had really started leaking, needing to be filled every couple days. We just pulled the assembly out of the machine; the seal appears to be a pretty typical oil seal, and there isn't anything obviously wrong with it. It isn't dry and brittle, the spring is in place, ect. I know from working on trucks and such that a leaking oil seal as often as not is related to problems inside the gear, not just a bad seal. From running the machine there is no apparent problem with the swing; it works fine. Is there anything I should be looking for here? Should I just replace the seal and send it? There is no endplay in the shaft, but from the size of the shaft and bearings I don't necessarily expect to feel problems by hand, unless it was total failure.
Sometimes it’s just the seal. Occasionally, the oil gets so hot and the pressure builds up and pops the seal. I have a drive motor right now, that I am trying to find a seal kit or individual seal for under 200 dollars. If it feels tight and you can’t get any end play, try mounting it in a vice if it’s out, then I would put a seal in it and run it. Just keep an eye on it and take the gamble. If you’re not comfortable with that, replace it, get a seal and you have a spare.
Has the lip of the seal worn a line in the output shaft that you can feel with your fingernail.?
Yes. It is not real bad, I guess in that I have seen a lot worse grooving, but you can certainly feel the groove under the fingernail.
That’s where it’s leaking. A new seal may not fix that, at least not for long. You may be looking at a replacement or refurbished shaft.
I knew you were going to say that . . . I have never been into a planetary before; what is the procedure for getting that shaft out? I assume the bearings are pressed into the shaft? I know the final drives often have things set at something like 3000 ft lb; that would be the case here also?
Doesn't look that hard and you may not have to do every step to get at the output shaft. See attached.
Thank you. I looks like I might only have to replace the spacer; #30 in illustration 14, at least in respect to the grooving on the sealing surface.
Do you have the parts breakdown for the swing drive.?
Yes, I have parts access on Sis
if you don’t feel like pressing the shaft apart from the carrier, I would consider a seal saver in that application.