Anyone know how to take apart the final drive on a Komatsu PC-78MR-6? The part number is 21W-60-41201. Brand name is Teijin Seikj. I think the drive motor is still good but the final drive sounds like its full of rocks. Can this be done without taking the track off?
You will have to remove the track to get at the final drive on the machine, there is no other way of taking it out and you will have to remove to see the damage - when removed you will probably find that the total costs of the parts to repair the final drive will actually come to more than it would cost to buy a complete final drive assembly - would definitely be worth pricing up a new one for a cost comparison before parting with any money for replacement parts to repair. Let us know if we can be of any more help and good luck - hope you get the machine going soon!
What about just taking the planterary gears out of the hub of the final drive while its still on the machine?
If it's just a problem with the planetary gears then you can do this without removing the final drive, but if it sounds like it's full of rocks then you may find that the main bearing and bellow seals are also damaged, if this is the case then it's much easier to remove the final drive to work on it - when reassembling it's best to turn it up and reassemble on the ground.
Click on my links below. We are the authorized repair center for Teijin Seiki final drives for North America. We stock parts to repair and complete units. It is simple to take this drive APART on the machine. The problem is getting it back together. Do NOT try to take it apart while it is on the machine.
Could you give me an estimate of or at least a ball park price to repair?
sounds like the splines on the drive motor are stripped out...........just sayin////
Well I got it torn apart last night and it looks like one of the main bearings has bit the dust and it chewed up both of the housings pretty bad, I dont think I will try to rebuild this one. I am on the hunt for a replacement. This unit is unlike anything I have seen on the net, it dosent have a ring gear per say. Its ring gear is made of two orbital sprocket like things that run on pins which are driven by three planetary gears with off set shafts, weird.
This style is called a walking motor. The three crankshafts "walk" the roll pins on the hub. Teijin Seiki created this style of motor in the 80's in Japan. It remains the most popular style of excavator final drive in 4 to 12 ton machines. You've found what we usually find when a customer sends theirs in for repair. You asked earlier for a ballpark price. I didn't give you one because I wanted to wait and see what you found. When one of these units can be repaired it is usually because it was caught very early and all it requires is bearings and a seal kit. But I'd say that is less than 10% of the time. When these fail, they catastrophically fail. And it is normally due to lack of maintenence. This units love fresh gear oil and when they don't have it they puke. Did you follow my links below in my sig? Have you contacted anyone at our company yet?
I have requested a quote from FDC but havent heard back yet. Ill keep you posted. Thanks for the info.
I show you were quoted last Thursday 1/10/13 by David. Did you email for a quote or call? I'll send you a PM with my direct line.
It looks as though you may also have contacted another one of our distributors, Brandeis Machinery. We've got you covered