Hola a todos We have this excavator and now it has this grinding noise when turning left or right. When doing it slowly there´s no noise, but at normal speed you can hear it clearly. Machine has almost 9k hrs Do you think it might me the swing circle bearing (big one)? Do you guys know some kind of test to prove it is that one?
Good day Andrew May I suggest you check out the slew transmission - drain some oil from the unit and check if any metal appears - if there is no oil take a loog at the swing gear lubricant to see if it has lost the oil into the pan. If we can help further just drop a mail to [email protected] we have comprehensive illustrations that may help. Kind regards Uffex
I would suggest checking the level of the grease in the swing pinion tub. There is a plate on the base of the house under the boom foot with two bolts in it. It is not unheard of for the slewing bearing to wear out as you stated. I usually use a dial indicator and check the up and down play in the bearing. Run the bucket to full dump, the stick all the way out and boom up off the ground slightly. I zero the indicator there and set the boom on the ground hard enough to pick up the tracks a couple of inches. I check how far the indicator has moved for the reading. New bearing movement is around 0.035 inch up and down. Badly worn bearings I've seen were at 0.100 inch or more. If you are that far worn you are looking at a bearing change. Good Luck
Thanks for the help. Tomorrow I will make the bearing test and tell you how it went
Back to report The bearing test went ok, so then my target was the circle motor. So I was going to drain oil and guess what, nothing came out, and it should have like 6 lts. I waited for half an hour and no oil came out. So I thought the swing motor was empty, but when checking the dip stick it showed full. So I removed the draining hose and connecting elbow to see what was going on at the bottom. When I put my finger there was something blocking the oil from coming out. It covered the complete hole. It was if a sleeve or bearing went to the bottom blocking the oil. Do you guys know what is the problem here? I suppose I will have to take out the swing motor...............
Komatsu only allows 3 mm. Max axial clearance.. Which is 0.120"...as john c. Stated check with dial indicator....
It has 1,80mm so I think is fine. What do you think about the oil not coming out from the swing? BTW grinding noise appears when you stop turning. If you do it slowly no problem. But if you turn fast and stop you hear the noise
I found a swing picture. The red circle is the elbow (connecting with the draining hose) I removed and when putting my finger felt right away something blocking the hole
Have you check any kind of damage there ?What's technition said about problem?
Today we removed the swing motor and brought it to the shop and no oil coming out (maintenance manual says it should have 6.7 lts) so tomorrow we`ll disassemble the motor and see what happened. Maybe is something related to the swing brake `cuz as I stated before the grinding noise shows up when stopping
Remember to post some photos of what you find.
Ok guys so this is the tearing apart. So we removed the 6 mounting bolts and swing motor out. This is what you find Next step is removing carrier assembly (notice is full of oil)
After that, removed the sun gear Then we took out the ring gear Now you can see the carrier assembly Now remove the holder bolt at the center And then you can remove the carrier assembly nº2
We drained the oil and you can see below the sediment Now we turn it to loose bottom bolts An now is ready for an hydraulic press to push the shaft from case assembly
Now you have the pics after the press.......
Now you know where the grinding noise was coming from ............!! Look on the bright side. At least repairing the swing drive box is easier than changing a swing bearing.
Oh yeah you bet. My bosses got the job cheap since we did it. Bearings are cheap (same brand as original NTN) so repair will be fast.
What about the busted gear..? Easy to get a replacement..?