1330 hours and two left drive motor pistons are hashed. Looks like they ran dry...anybody see this before? Cause?
Serial Number.? Hours.? What hydraulic oil are you running in it.?
Just over 1300 hours with Cat oil. CAT0259DECW915998
Under those circumstances and if the damage was limited to only two pistons out of nine then I would suspect a material fault. Do you have any photos of the undamaged piston slippers.? What were the symptoms leading up to the failure.? Noise, vibrations, etc.?
Left drive started to get a little "sticky"...not smooth. Especially when first applying power. In high speed it would bog on the left side.
So actually three pistons damaged and the other six not looking all that clever either. Maybe a particle of something went through it.?
On closer inspection, there are three damages pistons with a forth beginning to show wear. There is no obvious wear to any steel components. Other than affectied parts, oil and filter replacement, what should be my course of action in regards to the rest of the system?
Nige, Possible I suppose.is there a strainer that I should check for containments?
Do you have an Operation & Maintenance Manual.? Is it still in the pocket behind the seat.? If not then search for Cat Publication reference M0091175. They are $120 new so even a used one likely won’t be cheap. The manual can be downloaded from the Caterpillar Publications website. https://catpublications.com There is a hydraulic filter that you will need to change. At the same time the old one should be cut open and inspected for how much in the way of particles it has trapped. The issue is that the drive system and the implement system share the same oil, therefore a drive motor failure could easily take out a pump or a hydraulic cylinder. You need to identify how much in the way of particles from that failure have entered the system and where they ended up.
Yes, and so it goes. I appreciate you taking your time to respond.
I’m not sure those parts in your photo are available as piece parts. Maybe as a rotating group complete with the barrel.? If not you are looking at a replacement motor, which quite frankly would be the best solution for long term reliability. I think the drive motor should be available as a Reman part taking your old motor as a Core.
What does the swash and lens plates look like? How much sloop do the piston have? Be prepared that only salvageable part could be outside casting.
Swash plate looks alright. Some discoloration, impliying some heat maybe? Nige is right though, the whole rotating assembly is sold as a kit. About 1600.00. Still need to do a full inspection before ordering.
IMHO that's not a bad price. Check the output shaft spline on the motor, if it's damaged and depending weither a coupler is used or the sungear fits directly into the rotating group you may need one or the other also.
Sure thing. Odd how this happened. I wonder if a sudden stop under full power (such as a large rock lodged in the track) could cause this? You would think the system bypass should protect it. Pic shows the "rotating assembly kit".
Personally I wouldn’t contemplate replacing the rotating assembly without replacing the swash plate however good/unmarked it appeared to be.
Where are you getting parts? These final drives are not really serviceable through cat besides a whole reman. You're going to need to do a full cleanout. This machine does not have a return filter, so all debris from this motor has dumped straight into the bottom of the hyd tank. The hyd filter only filters the oil the charge pump picks up. Don't forget that all the ground up bronze from the motor ran in the drive loop back to the pump for god knows how long before it was pulled out and sent to the tank. I've seen this play out before and you might be ok, but you cannot shortcut this repair.
Greasynails, Cat sells part number 386-6631, which is the rotating assembly. I appreciate the insight on how the the system works. Looks like im in for a big job.
As mentioned earlier I wouldn’t consider replacing that assembly without replacing the swash plate as well.
Yes, I have the swashplate coming as well.