B7800 backhoe

[ChuckinNH]

Recently bought a b7800 with a woods 7500. I'm brand new to BHs but my engineering sense clearly supports the benefits of a subframe. The jolts and stresses of normal BH use are very high and just a 3 pt mount would worry me. Somewhere I read about a tractor with a just 3 pt BH literally breaking in half. Not sure its true but I can see (and have felt) forces that the subframe counteracts as a lever. It would also appear the subframe types allow more room for pto operated hydraulics. Beleive this allows for slower engine RPMs and greater efficiency. Again just a newbies .02.

The newer 4 point mounts use a full subframe too, but most of the frame remains on the tractor when the backhoe is dismounted. They are designed for MMM, and 3 point use, and are much easier to remove / replace.

 

[newbury]

Recently bought a b7800 with a woods 7500. I'm brand new to BHs but my engineering sense clearly supports the benefits of a subframe. The jolts and stresses of normal BH use are very high and just a 3 pt mount would worry me. Somewhere I read about a tractor with a just 3 pt BH literally breaking in half. Not sure its true but I can see (and have felt) forces that the subframe counteracts as a lever. It would also appear the subframe types allow more room for pto operated hydraulics. Beleive this allows for slower engine RPMs and greater efficiency. Again just a newbies .02.

It's been pretty much determined that the "breaking in half" is more urban legend. The Kubota "3pt" BH uses a very beefed up toplink.
My BX70 will pretty much haul my B7610 all around. A good curl on the bucket will lift the FEL with my box blade chained on it a foot off the ground in a heartbeat. I'm sure it would overstress a 3pt.
If the OP is going to use a BH a lot I'd go for the BX80. My salesman was trying to talk me into a B4672, and I'm glad I went for the extra foot of reach with the BX70.

 

[Ductape]

I'm 99.5 percent sure the new style (current) four point subframe for the BH70X and BH80X fits the 7500. I would check to make sure they are installing the hoe using the four point mount, not the old style ladder subframe that used to come with the 7500 (as Chuck suggested). For a thousand dollar savings, you should be very happy with the 7500. I'm one of the guys who feels the BH80X is a little over-kill on the 7800. Not that its a huge deal....... but i think the BH70X is a better fit for the B series Kubota. With the 80X on my 3030...... the front tires will come off the ground going up hill with an empty bucket.