rotary manifold
I've got a fair bit of slop in the swing, but am hoping it's just a bearing or something more minor. The main part that I need a manual to figure out is the rotary manifold assembly. It's leaking hydraulic oil from somewhere in there, but hard to figure out until I start pulling it apart.
Hopefully it's just an O-ring in the assembly, but my concern is that would only cause fuild to flow from one track motorto the other, not leak out. It's probably a liter per hour when we're using it, and drips for a while everytime you stop.
Kicker
I had the same thing happen to mine a couple of years ago, so I know all about what you are going through. Mine got so bad that it would leak about a liter in 10 minutes when I was using the tracks. First off, the rotary manifold (sometimes called the center joint) and the swing device (swing motor) are two completely separate parts. The rotary manifold is a pretty simple device with an inner shaft manifold, a couple of bearings, and bunch of seals, and a housing. The inner shaft manifold of the rotary manifold gets some wear after about 5k hours and allows the seals to leak. With new seals alone, the rotary manifold would start leaking again in no time.
I priced a new one, it was about $3500. So I took mine out and took it to the Deere dealer where they were able to rebuild it for about $700. They sent the inner shafter manifold to a local machine shop, where they were able to spray-weld new material on it and build it back up where it was worn away, then they ground it back down to original precision dimensions. Once that was done, they put it all back together with new seals and bearings. It took them about a week to turn it around, but it works like new and I would recommend this repair to anyone. The trick is getting the inner shaft manifold to a good machine shop that can spray weld and precision grind these kind of parts.
I was able to cross reference the rotary manifold for my '93 EX50 URG to a modern day John Deere 70D - which the deere dealer was able to get all the replacement seals and bearings for.
It is a pain to take the rotary manifold out, but there is no way around it if you have this kind of leak.
As for the swing motor or swing device as it is sometime called.
First off, make sure that you check the gear oil level on a regular basis. If you can't touch it with the dip stick- add some until you can. If you have a worn bearing and seal at the bottom it won't be able to hold oil for very long, so you will need to keep checking it regularly. I would keep running the machine for as long as you can - baby it..... What ever you do, once the gears start slipping, don't keep using it. The planetary gears are easy to replace, but the outer ring gear is not ( i'm not even sure it can be). If you keep using it with slipping gears you are will be chewing up the ring gear as well as the planetarys. That's what happened to mine, and the ring gear got beat up pretty bad. I was able to salvage the ring gear, but I wished that i had stopped using it long before I did. I hope you can learn something from my mistakes.
Good luck and let me know if there anything else you want to know about these parts.
Rush
:canada