My buddy had to repair his track motor on his ex60 in the field due to the O- rings failure. New o -rings (2) installed and when he started moving the track, all went well for 10 seconds then the track slowed down, then sped up and started leaking. Shredding the new o-rings. He cleaned all races and nothing else looked out of order before installing new o-rings. These are the new o-rings. Any ideas on the cause? .
I'm not familiar with the innards of an EX60, is that the seals for the final drive hub? Are those toric rings for floating seals?
Sure looks like it, sounds like either improper installation or something is worn to the point the seal is under too much pressure.
Those things looked to be squashed and then blown apart. Probably need a location of where these things are installed. They look a little small for the toric rings. I'm guessing it goes between where the motor mounts onto the final drive assembly.
Thanks for the reply's. I wasn't there when he did the work and I'm not a mechanic, so I'm not up on all the terminology. My buddy isn't that up on computers and posting to forums. Anyways, I believe they are "toric rings". I never saw the old set, but when I saw the damage to the new ones, I thought there were squashed more than they should have been. So, the reply's pretty much confirmed that. That's a large pizza box their on. They run about 3/8" thick and are about 8" round. If the final drive is up front of the track assembly, which sounds right to me, than, yes, it's the final drive. I can't vouch for the new install, but something did in the old ones, whether just use and wear or what, I don't know. Assuming the install was correct, what would be worn to cause the rings to be over compressed to tear apart like that, or, can they be over compressed on install?
Installing Toric rings normally requires special tooling to get the metal ring to sit at the correct height above the housing after installation. Some would argue that it's possible to install them using a couple of blunt screwdrivers but usually that is the type of job that needs to be done by a careful mechanic who understands the way the metal-to-metal face seals work and appreciates the need to get the final ring height correct. One thing your buddy needs to understand when installing Toric rings is that everything has to be cleaned with alcohol first to get all traces of oil off every component and that no lubricant whatsoever is permitted to be used when installing the Toric rings. Everything goes together 100% dry. I have a load of information about Toric rings and installing them - but that's on Cat equipment. However the way the seals work and the method of installation does not change whatever the make of the equipment. Send me a PM with your email address if you want some information. Just a thought. Post a photo or two of the metal rings in which the Toric rings are installed. We may be able to see something from that. Also a photo of the old Toric rings that came out when he did the repair.
I'll echo points that Nige made. If we are in fact talking about floating seals, the proper install is critical, components have to be clean, and I know they have to be dead nuts square, misalignment is not a good thing with floating seals.
Your problem is not bad o-rings, I`m betting the sprocket bearing preload is not to spec. As has ben mentioned the seals need to be paralell to each other as the sprocket rotates. I think yours is not. The only other issue I have ever run acros is a motor leak as it will fill the final drive with drive motor oil the same pressure as what the motor is running at. It will blow out the seal every time real fast.
After post #6 above I got to thinking that I'd seen exploding Toric rings like the photo before but couldn't remember where. Then it came to me, it was a hub where the flow of cooling oil was at a pressure about 5 times what it should have been. therefore I'm with Greg, before simply replacing the Toric rings again go looking for an internal hydraulic leak from the travel motor.
I'm picking warn bearings which is loading the seals. Just my 2 cents
Either way I think we're pretty much in agreement that the failed toric rings are a symptom of the problem not the root cause.
Guys, thanks for all the info. I'll pass it on and hope it helps him. The old rings were gone before I got there, so I can't send a pic of them and I don't think I'll be going back to the site any time soon. Speaking with my friend, he claims he has called in some experienced help. I'll post the outcome when it happens. Thanks again!
If it was leaking hydraulic that has to be it, brake seals? I seem to remember doing this exact repair on an EX120 many years ago.....
If we're dealing with radical ingress of oil from the travel motors into the final drives, then according to what Bcantell originally said, the machine only worked for about 10 seconds until it blew the seals, then that should be fairly easy to confirm. Place one of the fill/drain plugs in the 3 o'clock or 9 o'clock position, pull the plug. If it's overfull, allow the excess to drain out until it quits draining, re-install the plug. Operate that track for a spell, place one plug at 12 o'clock and the other plug at either 3 or 9 o'clock. Remove the 12 plug (to release pressure), then remove the other plug at either 3 or 9. If it drains a substantial quantity of oil you have a track motor problem.