I was just wondering why the bucket stopped curling down. Concerned maybe I had broke something. The last time I took her out I was trying to dig the ground to no avail. Just bouncing the machine around atop the Frost.
The sometimes droop and sometimes not is nothing to worry about. My Kubota TLB did the same thing. It's not unusual for the rubber sealing rings throughout the hydraulic system controls and inside a hydraulic cylinder to conform to the cylinder walls before they begin to wear. Yours sounds normal to me.
On your second question, I don't think that I've ever heard any proof that allowing the bucket to droop has caused premature wear or any other problem. Again, any hoe is going to droop the bucket as it ages. They all do, and it generally takes many thousands of hours for enough ring and seal wear to happen so that it noticibly affects the curl strength of the bucket. For example, my
M59 with 1000 hours will see the bucket start to droop a little overnight, but it takes days for it to point to the ground. On the older JD310 with 6000 hours the bucket starts to droop in a few hours. The point is that both machines droop the bucket, but I haven't noticed any lack of bucket curl force on either machine.
It sure doesn't surprise me that you couldn't cut through frozen ground with your machine. Our big JD has 100 hp and weighs ten tons but is still a little bit small and light for getting a bucket to penetrate frozen ground. Yes, it can be done...but doing so is really, really hard on the tractor. Now if I just absolutely had to poke a hole in frozen ground I'd probably go after the ground first with a hydraulic breaker instead of slamming the bucket down until something breaks..... Not recommended.
BTW, if you do find yourself needing to work in frozen ground, here's a link to the kind of tool normally used for penetrating frozen ground:
http://www.plowsite.com/threads/new-hammer-breaker-for-my-310-sj-tc-john-deere.98704/
The machine it mounts on is the same as mine. Injun, you'd better take a deep breath before you read what he paid for the hydraulic breaker attachment in the pictures. Of course hydraulic breakers come in all sizes. It wouldn't surprise me if you could get one for your machine. Once you get past the frost, the normal procedure is to dismount the hydraulic breaker and put the bucket back on. Your tractor's bucket backhoe bucket will pop the crust loose pretty easily from below.
Now having said all of that, and getting back to the droopy bucket I will also say that I think it is a matter of good practice and good safety to either lower all hydraulics to the ground or else chain or pin them so that they cannot leak down. If you do that, you absolutely know it is safe; and it might just be good for the hydraulic system as well.
rScotty
BTW, a friend in S.F. builds what he calls Vindian MCs. Nifty machine.