Thanks to lots of reading, mostly here in a few threads, I'm pretty sure my pinion seal is leaking into the slew tub/turntable and coming out around the dust seal onto the undercarriage of my PC200-3. I topped it up and it was low again after just a few swings. I got underneath the machine and removed the inspection plate and could see the oil dripping off the gear. So...I'm about to start the job of removing the swing gear/pump. I bought the service manual (at tradebit.com) and it looks pretty straight forward. But I'd love to hear any tips for removal, seal replacement and re-install that anyone may have. The pump ways about 400lbs, so I'm thinking I'll get a buddy with his large tractor to place the bucket overhead so we can chain hoist it up out of there. Anybody with any ideas to make this easier please don't be shy, I'm all ears! Thanks!
And of course, the service manual I downloaded from tradebit.com is missing most of the "disassembly of swing machinery" section...they copied the final drive assembly section twice. lol. Anybody know if I have to disassemble the entire swing machinery to replace the oil seal that is leaking?
Not sure on yours, a lot of machines the gear sets on the shaft and is retained by a plate and bolts. Older and some newer the shaft and gear are made together which means it has to come apart, while the newer once out, remove the bolts retainer plate/washer, remove the gear, then the seal retainer. I hope you have good luck and don't find a bearing issue also on the geared end. wrap the splines with shipping tape before sliding the seal on to protect it. Always try to move the shaft with the gear on it first to see if the bearing are tight before going in it. The bearings can be some real money also if needed to be replaced and as a rule most will likely replace them when pulling a unit down for a little peace of mind, it can cost a lot if the lower end fails. One other thing removing the swing box, some are a real tight fit and you may have jacking screw holes to get it to come off the lower structure.
Great tip with taping the splines. Also checking the play on the shaft and gear. Thanks Sheepfoot.
I used to pull the motor off the top of the gear box and then put eye bolts that I made from a couple of old swing motor mount bolts. Then I pulled all the bolts from the gear box. There are two or three jacking bolts in the mount flange that I cleaned out with a tap and then used a couple of mount bolt to jack the box out of place. Some machines don't have jacking bolts and if so you have to put some strain on the lifting bolts and then shake the chains hard to get the box loose. The problem then is lifting the box high enough to clear the top of the house. Usually a tractor isn't high enough. Remember the pinion gear goes down below where you see the bolts on the slewing bearing. When you get the box out you will know if you can get to the seal. If there is a cap and a bolt on the bottom of the pinion gear you are in luck. If not the box is easy to tear down until you get to the pinion shaft and self aligning bearing. Then you need a big press and someone who has done the job before to get it all apart without busting the case. As I recall all the Komatsu machines had the one peace shaft and gear. I hope I'm wrong on that for your case. Good Luck and stay safe. That box is heavy.
Komatsu don't have the cover under the pinion gear. the seal is not in a cover that you can split apart the final drive housing. You have to unpress all the pinion/bearing assembly. if you don't have a press it can be done with maybe a 30 ton jack. On a 400 -5 it took me a 100 ton press. I know its not simple but I suggest you to unpress it by pushing on the final drive body instead pusing on the shaft. Its more risky to push on the pinion as the load of the case don't help you, more risk to broke the case. as to press it back the shop manual told to press the housing on the pinion... not to press the pinion in the housing.
I checked the service manual and the gear and shaft are not one piece, but it doesnt show the cover under the pinion gear...****. I'm going to measure the height of the tractor tomorrow (it's a big T100 so should be high enough). And from the details I got from John C and Steve 650 above, I'm thinking the assembly may be put right on the back of the truck instead of into the shop. I'll call the Komatsu shop and see how much they think it will cost, and then make the final decision. Thanks for the help guys.
Learned something new today... If the gear case (pinion seal) is leaking, it will probably slowly drip into your turntable and probably won't ruin your grease there. If it is a slow enough leak, you could add a heavier oil in the machinery case and keep an eye on the level, may only need topped intermittently. However, if the swing pump seal goes, it will pressurize the machinery case and very quickly dump large amounts of oil into the turntable, coming out the dust seal around the swing circle. The pump seal, is an easy, quick and relatively inexpensive fix. The machinery case can be much more difficult and expensive to fix. Especially if the bearings are seized onto the shaft and need to be cut off. Just as Steve 650 mentioned above, pressing the bearings off presents a risk of damaging the case...$$$. Just more info for anyone that may be reading this in the future.
Figured I should update this post. I ended up having to remove the swing gear to fix the seal. It is at the bottom of te main shaft/spline and the bearings and race had to be pressed off (100 ton press required). The bearings (from Komatsu) are approx $850 each (2 of them) and the race is about $250. The actual seal is only $39.40. I had a backhoe come in with its bucket over the machine, to which I used a chain hoist to lift the swing machinery out of the excavator. In already had the swing motor off the unit. It can off pretty easy, but man it's heavy. I took the entire swing gear to the shop where I was told worst case scenario, both bearings would have to be cut off, and the race might break when pressing things apart. Luckily for me everything came apart with no further damage. Total hours was about 7 the total bill was around $1K. I dropped the gear back in, pit the motor back on top, and it's been working great since!
Nice work. Thanks for the follow up.