The best way to troubleshoot a problem is to understand how the problematic component is suppose to function in the first place. That being said, how does a slew ring work, what is its function? What other parts connect to it and what do those parts do? Reason for this thread is that i keep hearing a slight grinding sound whenever i swing the upperstructure and greasing doesn't seem to help. I've opened an inspection port to check the teeth and they don't seem worn.
Hi JVS, What kind of equipment are you operating that is making this grinding noise? It might save somebody some serious money to find the problem ASAP.
The grinding can very well be the bearings in the swing gearbox. You say you've opened the inspection port and inspected the teeth. How much grease is in the grease bath? How frequently do you grease the zerks on the outside of the slewing ring? Aside from checking the teeth and grease, you can check the tolerance or "play" in the bearing by turning the machine in a circle and checking the tolerance at 3, 6, 9 and 12 o'clock. You will need a dial indicator to do it properly. You push the bucket down into the ground and the bearing will rise slightly. Do this at those 4 points and see how much it lifts. Report back with Make, Model and Serial number and I'm sure one of us can tell you what is within reasonable limits. Good luck.
Well the teeth seem to be well greased, but the grease bath isn't full. Should it be?
Is the swing gearbox the same as the swing reduction gears?
I probably should mention that you will feel the grinding whenever you slow to a stop not while swinging.
The grinding noise can be anything from a piece of sheet metal under the house hitting one side of the ring to a bearing in the reduction box going bad. Usually when the bearing is going bad the case hardening on one of the races has been crushed and is flaking off. The flakes will generally get flushed out when you grease the bearing. Most of these bearings are just over size ball bearing and race designs. I've heard that Cat now uses a roller bearing instead. The carbody side race has a ring gear on it that engages with the swing reduction gear box which is attached to the house. I have also seen the ring gear tub not have enough grease in it and the pinion gear will squal but that usually is pretty extreme. I have also seen machines that have worked in rivers fill up the tub with sand and wear the gears out. This should give you enough to think about for now. A photo of the subject machine or at least the make and model would be interesting to know.
John C, If youlook for a thread titled "Strange thing happened today" you will find two pics. Its an 06 CX210
Recent pic Here it is
I would think that if your grinding noise is coming from the slew bearing, you would see some excessive movement in the upper structure. It may also be your swing brake is activating to quick. Does that machine have free swing option? If so try it with the swing brake off and see if you have the noise.
It sounds to me now like the grinding you are hearing isn't actually grinding at all. It is probably the cross over reliefs doing what they are supposed to do. When you let go of the contol handle there is nowhere for the oil to go to. The spool shuts off the flow to and from the motor. Now the motor turns into a pump and pressure is held on the outlet side of the motor at the relief pressure which dynamically brakes the swinging house. I've seen the reliefs set up to vent directly to tank and others vent into the suction side of the motor. At any rate unless there is something you don't like about how the machine swing is operating I wouldn't think you have any problems at all. By the way, nice looking machine!
Thanks, I hope you are right. This my first machine, not very experienced so i'm very careful to check on anythig that may sound even a little odd. I'll still run all the other checks suggested just to be sure though.
Slew ring I have just purchased a 307 cat and the house appears to be wobbling. I purchased machine knowing this issue. the person before me must have thought adding more and more grease would fix it as grease is expelling out of the main house seal everywhere. Do I need to remove swing motor to replace slew bearing? Or can I just unbolt house and lift it straight off?
hey jvs i ran a case cx 210 that was a 06 as well did the very same thing we never did find the problem befor it got sold might just be a case thing i dont know
I operate an 09 Hyundai 160 with 600 hrs. It somtimes makes the same noise you are describing, usually after several hours of the same movement. "like loading trucks from a pit". When this happens I can grease the slew bearing then get about a half bucket full and swing 360 a few times and it stops. Hope this helps.
we have a jd 135c and a tachi 160 and they both make a simaler noise. when you swing and stop under heavy load it seems to do it the worst.
My komatsu PC-120 does the same thing. It sounds like when you put a mini van in reverse; sort of a high pitch gear whine noise, then when you stop suddenly with a heavy load it gets louder. No amount of grease has helped, the swing motor seems fairly strong and the swing bearing dosent have too much play in it. The noise still worries me but I havent been able to pin point where its coming from and the last thing I want to do is go replacing parts without a solid diagnoses. Im pretty new to this stuff too so I'm glad this question got brought up.
Every excavator I've ever run makes a faint grrr... gear whine when you swing hard and gets loud when you slow down, some machines louder than others. I don't know exactly what makes that sound but it seems to be normal.
Just picked my 307 up from Milton Cat today after having the turntable bearing replaced. The boot on the swivel was letting water in, it was dry rotted, plus the service manager thought that having a 30" bucket along with a thumb and long stick/ reach boom was putting a lot of stress on the bearing. Machine is 16 years old with 5900 hours. Doesn't owe me a thing. I think I got the last bearing in stock in the US from Morton that Cat had in stock.. They did remove the swing motor and checked the gear to see if it was still within spec, which it was. I also had the swivel rebuilt, about a $1000 with parts for that. The final bill was not done, but should be close to the job quote.