I have a JD 70 d Excavator (same as Hitachi EX 60). Today it quickly dumped all the hyd oil from the right rear final drive (appears to be on the inside, maybe between motor and sprocket?). Any idea what this might be and what I need to do to repair. I'm a novice excavator guy. Thanks much.
Hi Bull, The sequence of parts likely goes like this: pump --> hoses -->( mcv -->) hydraulic motor --> gearbox --> sprocket --> chain I don't know if there is a mcv on this excavator, but it could be defunct seal between the motor and mcv (motion control valve). It could be the hose connection... It could be the gasket in the gearbox is toast. Can you post a picture?
Does it smell like gear oil or hyd oil. Gear oil is pretty easy to tell, terrible odor. If it's gear oil, likely failed seal for planetary hub (final drive hub).
Sounds like a hydraulic hose rubbed against the frame and is leaking down and out the motor guard. Gear oil would have to leak out the sprocket seal and you would be able to smell that a long way away.
Sounds like its the brake piston seals! done a fair few of these this past year, not a big job to do! remove the motor from the f/d (no need to remove the complete drive unit) and youll see a brake spring, remove this and youll see the piston! take it out and theres 2 D-ring style seals a big one and a smaller one! Aiden
These units are notorious for doing exactly what cps stated. Hydraulic oil points to the motor. If it was gear oil I would say the duo cone seal on the gearbox. Follow cps advice first
I currently have one of these same EX-60 finals torn down. When I first saw the machine it was leaking hydraulic oil and I did not smell any gear oil. When I removed the final drive from the machine and drained it there was no gear oil in it, only about half full of hyd. oil. The rubber o-rings in the duo cone seals had both dis-intergrated and were leaking. They had been digging in wet clay and had the under carriage packed solid. So my thought is that the gear oil leaked out and was absorbed by the clay and when they washed the machine they noticed the leak. So new duo cone seals, replace the brake seals and reseal the motor ect and it should be good to go.
Sorry about taking so long to update. CPS hit the nail right on the head. It was the brake piston d-rings. Fixed me right up. Machine runs and operates great. Thanks to all for the help, especially Aiden. Best, Bull
Great stuff Bull, glad you got sorted:thumbsup Only to glad to help:drinkup
I have I have the same problem with my 70d hydraulic fluid coming out fast but can only see it dripping on the bottom half of the sprocket, I tore into it tonight this us the first final drive or motor I've messed with. When I pulled the motor there were two split floating seals that look really new. We're should I check from here. Thank you, Art
Got a 70D with a leaking final drive. It leaks out as soon as I dump hydraulic oil in the hydraulic tank. From reading others comments, I need to replace O-rings on the break section of the drive. Also noticed a large seal falling out so I need to completely tear drive apart. Problem is I have part of it torn down but got to a point that I’m not sure how it comes apart. Anyone have a link, picture, video or any idea how I can get it disassembled? This is my first time getting into a final drive. Thanks in advance for any helpful info.
Not sure where you are in the disassembly process. Remove the motor #00 and belleville spring washer #42 and pull out brake piston # 39 to replace the o-rings on it. . https://partscatalog.deere.com/jdrc/sidebyside/equipment/63405/referrer/navigation/pgId/2950 . . To replace the duo cone seal assembly # 5, remove the front cover/ carrier assembly#25 and carrier # 16 to get to large nut # 12. Pull / push / destroy locking dowel # 13 from the nut , Support the weight of the sprocket and drum #6 with a strap and lifting device , rap the nut #12 with a bar to spin it off. (You will need to fabricate a socket to torque the nut to spec when going back together) . Pull off and remove the ring gear #11. Remove the sprocket and drum , Remove duo cone seal assembly #5. .
The hydraulic oil could be coming from the brake piston leaking but also very likely be coming from a leaking drive motor shaft seal .. .https://partscatalog.deere.com/jdrc/sidebyside/equipment/63405/referrer/navigation/pgId/2825 . .
The locking dowel is the current struggle. Not sure how it comes out without destroying it or something else. I have yet to take the motor side apart…..do I need to take motor side apart to get dowel out? Disassembling unit in the machine, only because my dad insist it be done like so. I keep telling him we should take complete drive out but I’m respecting my elders as taught.
I’m assuming all the seals are leaking at this point. Not a trace of gear oil in it, all hydraulic oil. I’m just happy everything is clean other than a little bit of metal shavings and I believe they are brass as they appear to have a gold hue.
Removing the motor will not get you to the dowel. I want to say drive the dowel thru but I’m almost sure it will hit the back of the outer bearing cone. Is the dowel flush with the face of the nut or is it set in a bit.
The dowel is recessed slightly. I tried pulling it with a magnet and tried tapping on it, no luck. Adjusted the large nut making sure it was not in a bind as well. The bugger does not budge at all.
Debating on drilling the dowel to get a bite on it
The dowel material is likely hard as can be. I see the hole in the ring gear is not a blind hole so they must expect the dowel to be driven in to the ring gear and out of the nut and then removed from the ring gear after it’s all apart. Also , I was in a manual for a similar vintage but a bit larger Hitachi and the dowel was driven in.
I was afraid that dowel was hardened. I’ll see what I can come up with tomorrow. Thank you for your helpful knowledge, it’s greatly appreciated.
Update; got it apart. Ended up drilling and grinding the dowel down enough to spin the nut off. Turns out I could have hammered it in farther, plenty of clearance. Whenever the other side starts leaking, I’ll know I can simply drive it in more to release the nut then drive it out for reassembly.
That’s awesome ! I will put that in my mental archives for future reference Good luck with the rest of the repairs .