Well yesterday my boss had me tear a final drive apart because of the constant oil samples coming back high in silicon,the report said to flush and refill and then recheck in 100 hours but he got nervous about having a failure.Two other kobelco machines are coming back with samples saying the same thing that it is urgent stop machine.My question is,if we are sending the samples to caterpillar are they using a gear type planetary-final drive,for a baseline on teardown or do they realize that hy-dash uses a gearotor design in there drives which i believe would show more wear metals etc.By the way i found nothing wrong inside final drive(just as i suspected)but we are rebearing and resealing it to the tune of 4000.00 parts are ridiculous for these machines.
Sell it and buy a real excavator
Silicone in the oil. Hello. A Kobelco has several Silicone seals as well as Silicone in the lube. http://www.kobelcoamerica.com/FILES/tbl_s22ProductText/PDFFile90/527/ED195_EZprint.pdf And, I happen to like Kobelco, so if somebody told me to "Buy a real machine"? :bash Anyhow, get the raw data from the analysis and talk to Kobelco, and not Cat, and see what they have to say about this.
This is what i had in mind ,was to talk to kobelco,but im not the supervisor and it usually dosent matter what i say even with 25 years of equipment repair experience!!
whatever dude
Ok I will be nice Sorry just not an Kobelco fan, I own a fleet of Hitachi's and deere. Good luck though.
I think you could buy a reman final with warranty for not much more than that
We run kobelco's and deere (aka hitachi with deere engine and yellow paint) The kobelco's will dig circles around the deere machines.But all machines have their pro's and con's.
I agree with you they all have pros and cons, but as an owner the deeres and hitachis bring twice as much when it comes to trade in time. I will leave it at that, its like chevy, ford or dodge.
Silicone is a sealer while silicon is dirt. The readings could be from the way you take your samples. Do you use a vacuum pump into the sample bottle or do you spill some oil out into a jar? The only way dirt gets in these units is by a leaking seal or someone dumped it in through the fill plug. Try sending in a sample of clean oil and see what you get. If the Cat dealer says flush and resample you should be OK to do just that. The final drive oil is separate from the drive motor. The motor is not geroter type but instead an axle piston motor. The final drive is most likely a double reduction planetary unit. I'm quite sure the lab knows the difference. I would not tear down one of these units unless you absolutely have to. Good Luck!
kobelco 135 propelling drive Maybe im wrong but the planetary has one gear set and....well heres a picture!
I see a pinion gear turning against the front gears on the planetary and a ring gear for that set. The large ends of the planetary gears turn against the outside ring gear which turns the sprocket. I believe that makes this a double reduction planetary.
Sorry wrong parts pic,i only have one set of gears as stated and they are on the outer part of the drive,the inner part cosists of 24 pins and 2 plates with indentations along the outer part,then 3 shafts gothrough these with offset bearings that in turn rotate along the pins spinning the outer hub,kind of complicated versus gears imo.
That's interesting. I've never seen the a walking planetary used on a machine bigger than nine metric tons, mini excavator size.
The SK135SR takes part number YX15V00003F2 and it is a "walking motor" This design is a GM18VL2-K series and was used on the Kobelco SK115SR, SK135SR and Case CX130 and CX135. The typical failure on this unit is the coupling that couples the motor shaft to the sun gear. The sun gear shaft splines strip. I hate that they changed the design to a sun gear with a stub shaft, it was an awful design change. I agree with John C., don't pull it apart unless you have must. Once the three reamer bolts are removed from the spindle, they never seat the same again and failure is never far off.
Hi there Finaldrive, I've heard of four different machines doing this in the last six months! two Hitachi minis and a 13ton hitachi and case excavators! Is there a know cause or prevention for this? Or is it normaly just put down to design faults? Just wondering!
Hi there CPS I imagine the Hitachi mini's were EX25 machines, they take a Kayaba brand drive and are notorious for this problem. The solution we came up with for that was to change the motor shaft and sun gear. We have a machine shop make us new drive shaft set ups and it has fixed the problem. It still requires disassembly and reassembly and is not cheap, but it is a fix. The GM18 size we have not found a succesful solution, we've tried different things and none of them hold up very well. Aside from routine oil changes of the gear oil, I don't have a solution. The "walking motor" is being retired by the factory in Japan and they are changing to a double reduction style final drive on new machines. My job will be to cross reference the technical specs and see what we can put in place of the GM18. The maunfacturer dismisses design faults and blames it on poor maintenence and incorrect operation of the excavator.
Well like i said i dont call the shot but i did mention to my boss it dosent need disassembled,i cant help he wont listen to me:beatsme=BOSS
you got that right!!!!!!
if you end up pulling it apart. agree with the 3 reamer bolts. these act as dowels and must be true when put back. if the carriers are oblonged or the reamer bolts ruined when removing they must be replaced. this final drive is a hit and miss when overhauling. one good point is do not use an impact on removal of the reamer bolts. if you attempt to they will pile up. for a reasonable cost you can purchase a brand new complete unit direct from H&R Construction parts. apples to apples fit and in all purposes the same as OE but at a much less cost. they are not worth monkeying with.
Which one do you recommend?
Replace the oil every 500 hours minimum. Every service if used in extreme conditions.