Backhoe Newer JD backhoe vs older #7 backhoe

[ktm010]

Just mounted a #7 backhoe I recently purchased, curious if someone has had the older style, wondering how much better newer hoes are, hydraulic power wise, I was going to add a thumb, but side power seems low. Any comparisons would be great.

 

[AKfish]

Just mounted a #7 backhoe I recently purchased, curious if someone has had the older style, wondering how much better newer hoes are, hydraulic power wise, I was going to add a thumb, but side power seems low. Any comparisons would be great.

Welcome to TBN - ktm010. What tractor model did you mount the #7 backhoe on? New tractor.. older tractor? The hydraulic system of the tractor will determine (to a great extent) the performance of the hoe.

If the hydraulic pump on the tractor is worn or not operating at new specifications (GPM and PSI) or the pressure relief valve is adjusted too low, the hydraulic performance of the backhoe will certainly be less than optimal.

The #7 hoe is an older design and there have been only minimal changes in the past 10 years or so. The swing cylinders are now 2-way hyd cylinders instead of the older chain-link design. Beyond that, there may have been improvements made to the materials (packing glans and wipers) in the cylinders, etc. but the basic capacity and capabilities are unchanged - IMO.

It's a solid, reliable and time proven design that JD has continued to offer with their "value" series of small CUT's.

AKfish

 

[ktm010]

Tractor is a 1995 model 955 with 650hrs (manuel says 2500psi working press. Pump capacity 7.2gpm). The hoe I don't know the age, but has very little use on it, came off a 856 tractor. The hoe has hydraulic cylinders for boom swing, I would guess 15 years old maybe. I only ran the hoe for 1 hour, but seems to lack power from side to side to backfill. Maybe I'am just expecting to much from this small a unit. How would a #7 hoe compare to a newer model the same basic size say a JD48.

 

[RobS]

Swing is definitely the weakest movement of the #7. You can probably hear the relief valve squealing as you load up the swing. There is a seperate relief on the hoe just for swing. All other functions depend on the tractor relief valve.

I don't know about any other units but I do have a 7 on my 790. It's not the strongest, but sure beats a shovel!

 

[dfkrug]

Swing is definitely the weakest movement of the #7. You can probably hear the relief valve squealing as you load up the swing. There is a seperate relief on the hoe just for swing. All other functions depend on the tractor relief valve.

Are you sure there is not a relief valve on the hoe valve stack? Most
hoe attachments have a RV that protects all the work circuits, in addition
to sometimes having individual RVs for some of the work circuits. These
latter RVs are usually "shock relief" type valves with settings higher than the
hyd pump can deliver.

Side swing forces on the hoes I have seen and owned are limited by the
very short moment arm of the cylinder attachments. In order to get the
full 180-deg of swing, the 2 swing cyls will often go "over center" of the
swing pivot at the extremes.

I have not had the JD7 hoe, but I have used extensively hoes of about the
same size on my 955s. The only issue I see with that is that is a very light
tractor and it gets dragged easily by the hoe.

 

[hemiguy]

Hi ktm010,

I wouldn't compare the #7 hoe to the #48 as that is a much heavier 8 foot model made for the newer 3000 and 4000 series compacts. Those tractors weigh around 1000lbs more than the older 55 series like your 955 and the newer 2000 series like my 2520. I'd say the #7 is more comparable to the #46 hoe that I have (but 7 foot dig depth vs 6.5). Yes, they are weak in the swing motion and I think I've seen in my manual that they don't recommend you use the swing to backfill (but we do it anyway). I've found you just have to go easy and start at the top of the pile. As the others have said, the hoe will throw these small tractors around quite a bit compared to the larger machines. Don't know what it would take to add a thumb on these as I've never needed one.

 

[dfkrug]

I'd say the #7 is more comparable to the #46 hoe that I have (but 7 foot dig depth vs 6.5).

The 7 is a 7.5-ft class of hoe attachment, like the newer 47, and then the
447 curved-boom hoe. The latter 2 models seem to have been replaced
by the new 375 7.5-ft curved-boom hoe. The 7 and 8B are still offered to
support older designs, like the x55s, and the x70 models.

So a tractor like mine, the 4300, which specified the 47 or 48 hoe, now
calls for the 375 or the 485. The 485 is the 8.5-ft class hoe that
replaces the 48 and 448 models.

 

[hemiguy]

Ok, I'm afraid I have to disagree with dfkrug and any of you guys that are comparing apple to oranges. OK, at 7.5 feet (not 7 feet, I stand corrected) the #7 hoe was still designed for small frame tractors (955 etc, and 790 which is now 3005) The 447 and 448 for medium/large frame tractors (4300 would be considered medium frame 3000 lbs). The 475/485 are just modified curved boom designs of 447/448 for cab tractors. And I still say a good part of your useful performance of these things is related to bulk of the tractor it's attached to, lb for lb the 955 being one of the best Deere has made. Here are the specs straight from deere.com. They don't provide any specs for 47/48 hoes.

boom lift cap/dipperstick digging force/bucket digging force
#46 348lb/1250lb/2450lb
#7 200lb/not specified/2400lb
#447 595lb/2005lb/2840lb
#448 820lb/2435lb/3730lb

Sorry, but as they say, it is what it is.

 

[dfkrug]

Ok, I'm afraid I have to disagree with dfkrug and any of you guys that are comparing apple to oranges.

Hoe attachments are comparable by digging depth primarily. Force
specs quoted in brochures do not always apply to the tractor you are
using. For example, many of the budget JDs (x70) supply only 2000-2100psi
with their implement pumps, while the 955, 4310, etc supply about 2500psi.
If the main relief valve on the hoes were set at 2100psi or lower, then
you can compare the forces fairly, but brochures do not usually state the
test conditions. It is also true that some 6.5-ft class hoes can exert
some greater forces than some 7.5-ft class hoes, due to shorter booms/
dippers and similar cylinder sizes. Digging depth is still the key spec for
most buyers. Because specs in the brochures are of questionable value,
I think it is more useful to compare hoe forces of the same class by
looking at cylinder size and dipper stick moment arm ratios. I also look at
how the hoe is constructed (gussets? pin size?) to see how they compare
for strength. The RVs are usually adjustable.

The JD Configurator has replaced the 447 and 448 hoe listings for the
tractors they were designed for, with the 375 and 485. This implies that
the former units are no longer available, and have been updated with the
new designs. Also, the 7 and 8B are still available, but not the 47 or 48.

 

[DJCohenour]

I have an 8A on a JD 950. It has a digging depth of about 8.5 feet, if I remember correctly.

I would also have to agree that it is very limited in the side pressure department. All in all, I wouldn't complain about it at all. While I sometimes am limited in what I can do with the swing of the boom, I still love the hoe and what it can do.