Hi All, our 312c has developed a loud "humming" noise from one of it's drives, no grinding or tearing noises and it's working fine, it has been operating in deep muddy conditions for the last few days which probably isn't ideal. Any advice as to where to start looking would be greatly appreciated. Thanks Brendan.
Have you drained and refilled the gear hub? Or at least let it set overnight with the drain plug at the lowest point then ease the plug out to check for water in the oil?
Thanks lantraxco, we haven't done anything yet, that's probably the first and easiest place to start alright, there is a possibility that some fencing wire got wrapped around the drive and cut the seal, it's been working in pretty rough conditions over the last few days. Do you think that contaminated oil would cause this noise?
The possibilities are many, but my first thought is a hub full of water? Checking the oil for water and also metal particles will either show a problem or pretty well eliminate the gear side from the equation I think. Hard to say what there is inside the hydraulic motor that would cause humming, piston coming apart, bad bearing, could be parking brake hanging up.... may have to open things up.
Write your contacts in this [email protected] we will send you drawings. Tell us the series nimber of mechanizm (send id plate)
UPDATE: We drained the oil and it didn't have any water in it but it did look metal grey!!! So we took of the cover and removed all the planetary gears and all were good. Next it was off with the track, we ran the motor and it seems good. I spun the sprocket by hand and I can hear a distinct rough bearing noise, problem found. Any advice on how to change this bearing would be a great help, should I also change the seal, if anyone has a parts breakdown it would be appreciated sr CAT0312CCDBN01139. Thanks in advance Brendan
Yes replace the seal. https://parts.cat.com/AjaxCATPartLo...7zxPMbw==&storeId=21801&serialNumber=DBN01139 Should get you there for parts picture, if not we'll try something else. You'll have to make a spanner or find a service man that has the correct one, dealer maybe, to remove the big ring nut, after that the bearings and half the seal come out with the sprocket hub. Other half of the seal stays with the motor end. Talk to CAT about the torque for the ring nut when reassembling. Better men than I will have better advice.
Thanks lantraxco, I appreciate all that, the link worked perfectly, so I have my parts list now, any idea how to remove that little dowel, it is loose but there's no way to grab it!!!
No, not familiar with that one... magnet?
No bother lantraxco, you've helped loads already, it's fair to say that you have saved us from a lot of sweat and cursing, ha ha. This dowel is a silly looking thing, already tried a magnet but no luck, i think I'll try a small drill bit and a self-tapping screw.
I can't tell from the parts drawing, some of those drives you drive the dowel in gently with a small hammer and punch, then you can get it out once the ring nut is removed? Doesn't look like one of those to me, but maybe you can see some clues on the real thing?
You changed the D bearings. Now you need to adjust gears A and B. Flange C press gear. How much to press in. Need to do surgery, every 1/4 turn. Put a paper strip between the cogwhell tooths and turn the cogwhels. If the paper strip is cut off, flange C needs to be released. If the paper isnt cut, the flange of the C needs to be tightened until the paper toothbrushes begin to cut. Or take you to the service specialists.
You changed the D bearings. Now you need to adjust gears A and B. Flange C press gear. How much to press in. Need to do surgery, every 1/4 turn. Put a paper strip between the cogwhell tooths and turn the cogwhels. If the paper strip is cut off, flange C needs to be released. If the paper isnt cut, the flange of the C needs to be tightened until the paper toothbrushes begin to cut. Or take you to the service specialists. View attachment 170735
Sorry, the picture you have there is for a hypoid gear, we're working on a planetary hub here....
Hi all, UPDATE. Opened up the drive today and sure enough we found some fencing wire in there, seal and bearings didn't seem bad but we had a new set, so in they went, put it all back together, filled it with oil and gave it a spin, but luck is not on our side, the loud rough sound is still there. We took the cover off again and removed and rechecked all the needle bearings, but all look fine. So now it's onto the motor, any advice as to what we might find in there would be greatly appreciated also I could do with a parts breakdown. Thanks Brendan
While it was apart did you check the lash in the gears. Worn gears can give a similar sound.
Let's go back to spinning the sprocket by hand with no gears in the hub... did you try that before reinstalling the gears, see if the noise is still present? If it is, there's something still amiss where the fence wire did some damage?
Tones, I didn't check the lash, but there's no real amount of wear on the gears, although it does have that sort of a sound, also this sound started all of a sudden. Lantraxco, I did spin the sprocket without gears and it felt smooth it did have a little more resistance which I presume is from the new seals, I couldn't see any other damage from the wire, I found it lying just under the seals. Thanks Brendan
Hi all, We took the motor off, maybe not the correct way, but we found a problem, there are 5 large ( 6" ish) bevelled washers ,that surround the piston group, one of them is broken open. So my question now is can the motor be put back on with the drive still in place and a parts breakdown would be a great help. Thanks Brendan
Pretty sure that when I changed a final drive on cat 312, removed motor first and refitted last, so yes to question about leaving final drive in place.
Looks like an integral setup, I *have* done similar motor repairs without pulling the final out of the machine, but it's a joy getting everything to stay in place while you install it all sideways. I use white lithium grease to stick parts in place, typically hydraulic oil will dissolve it quick enough once you start it rotating. https://parts.cat.com/AjaxCATPartLo...NY7W0GA==&storeId=21801&serialNumber=DBN01139
Lantraxco, your spot on, we spent 20 minutes playing with it and decided the only way was off with the track again and take out the drive. No. 19 "spring" is the piece that failed. We're not altogether convinced that it would cause the noise we are hearing but it's broken so we will put in a new one and see what happens, everything else in the motor looks, as new. Should have it by tomorrow, so until then. Thanks Brendan
Maybe you can send a photo. What are you talking about THANK YOU
Hi all, we put the motor back together and reinstalled the drive, it ran with only a little noise, but when we put the track on, it was back, loud as ever. At this stage we're fairly sure it's coming from the drive side and that the motor is ok but just can't see any issues in there, so for now it's going back to work, maybe in a month or so we will pull off the outer cover again and see if something has developed. The joys of all things mechanical!!! Brendan
Hi all, I have an update, we ran out of time with the diagnosis, we needed this to be working so we contacted CAT Finnings for a price for a complete drive and what a surprise we got €23'500 + vat !!! After that we asked a local supplier who remembered somebody putting a Hyundai drive on one, he had one in stock and for €3'500 we took it. It fitted perfectly, the only thing we had to do was to extend the 1/4" hose but everything else was spot on, it's been working now for over a week and we see no issues, there's more than one way to skin a cat!!!