448 BH on 4520: is it just me?

[tom30519]

My new 4520 with 448 backhoe was delivered at the end of the afternoon on Friday. It was snowing hard, windy and getting dark, so I reluctantly backed it into the garage and tucked it in for the night.

Yesterday (after spending more than a few minutes admiring all that spotless green), I took it outside to get in some play time (might as well admit it!) with the backhoe before replacing it with the rear blade.

I can only compare with several mini-excavators I have rented over the years, but whereas the dipper, bucket and swing controls are all easy to modulate, the boom control is very sensitive, particularly pulling it in, and I found it difficult to move it smoothly, even though I had the engine revs down around 1100.

The outside temperature was around 10F, if that makes any difference, but the oil should have been well warmed up from using the loader to clear the (tiny) amount of snow we got in southern Quebec Friday night. So, I'm wondering if other 448 owners have noticed that the boom control seems to be more agressive than the others. Is this something I can adjust? Or do you think that this is normal, and it is more a case of me having to get used to it? (More seat time! Yay!)

Larry? Anyone? /forums/images/graemlins/smile.gif

thanks,

Tom M.

 

[GalwayBoy]

Hello Tom,
I have a 448 BH on my 4120 and have the same situation.
The only time that it is an issue for me is when bringing the boom up to park, where it will bang into position. I curl the bucket up at the same time I'm parking the boom. It seems that using any other function will slow the boom down to a manageable speed.

From what I've read here, it seems that it's the nature of the beast- and that if you want valves that you can really feather, you need a true construction BH. (which I've never had the pleasure to operate)

FWIW, it does become less of an issue the more hours you play ( work ) with it.

Jon

 

[Chris_VA]

Guys,

I put a hydraulic cylinder on my spreader to open and close the gates. When I first put it on, it was too fast to control. I found a flow restrictor (somewhere) that went in-line with one of the couplers. Basically, it was a thin piece of metal blocking the flow with a small hole in the middle. It made the cylinder much easier to manage now that it moves more slowly. Do you think reducing the flow would also kill the power on that cylinder on your hoe? I bet it would. You would want full flow for the most power, right?

Chris

 

[tom30519]

Good point, Chris. I definitely would not want to reduce power to the boom!

Today I used the BH to sort my pile of fieldstones, and with the dipper extended, and doing real work with weight in the bucket, I found the boom MUCH easier to control. Plus, of course, I was getting used to the 'touch' required. After a couple of hours I was able to get back into the swing of using a backhoe, but by then the blowing snow had started up again.

So it seems that Jon is right: the more I work with it, not just hacking around, the less of an issue it will be. Already I'm finding it workable, even if I'm not smooth on it yet. That'll come in time.

thanks,

Tom.

 

[gizmo]

I have an 8B on my 990 and it does exactly the same thing. It took several hours of operation for me to get the thing under control.

 

[GoodGuy]

Tom....
Agree with other posters. I have a 4210 with a 47 hoe & complained about that problem here & was told "get used to it". I also complained to Deere & know the technician personally & he tried his best by adjusting the rods & lubing the valves but the same problem exists. The more hours I use it, the more I can adapt but it sure would be nice if the hydraulics were somehow "equalized". My 2 cents

 

[plowrup]

I would not recommend put a restrictor in the circuit, it wil contribute to more oil being pushed back over relief, which will heat the Hydrualic oOil (not always a good thing). With regard to the touchy feel, I would have to chekc the Parts Book, but usually most Backhoe Valves have a Circuit relief vale which can vary the amount of flow gonig to the Cylinder-it will affect digging capacity to a degree, however-

 

[mjm1]

Tom, I am very happy that you raised this issue. I have been putting off buying a 3x20 of 4x20 for almost one year due to the extreme "twitchy-ness" of the backhoes. We have rented both mini-excavators and CUTS, and their is no comparison. I cannot understand why the CUT manufactures cannot solve this problem. Otherwise a CUT has broader applications for our purposes (general landscaping contractor - small 2 person operation). I was hoping that a valve of some sort would help, but that would appear to rob power. I guess I'll keep waiting for one of the manufacturers to solve this. At this point I will buy from whoever does; I prefer green, but will go to orange or blue if the machine works smoothly.

 

[plowrup]

Why not buy a 110TLB?

 

[tom30519]

I don't know why the mini excavators are easier to control, but my impression is that they definitely are. Perhaps it's a question of a more expensively (asymetrically) machined spindle in the valve. Certainly one wouldn't want to put in a restrictor valve, or bring down the relief pressure adjustment - it comes down to the valve spindle, in my opinion.

I've taken the BH off because I'm using the tractor to pull cedar trees out of the woods while the ground is still frozen. But I will say that in the few hours I did spend working with it, the twitchiness became less and less of an issue as my hand-eye response improved. I won't know for sure until spring, when I'll start removing stumps, but I now feel that this will not be a problem.

Tom.