BH and MMM for B7800 or L3400 Subframe, 3pt ???

[Volnavy]

I have been looking at the pros and cons between these two machines and thought the main con of the L3400 was the loss of the mid PTO and thus the loss of a MMM. However, when I was at a local Kubota dealer today the salesperson said if I wanted a BH on the B7800 they would only sell one that comes with a subframe and I would lose the MMM on that model too. The web site says the B7800 comes with either a B4672A or a BL4690A and that both can work with a MMM. I recall someone talking about being able to pin the MMM mower up or having to remove it. The L3400 comes with either a BH75 or a BL4690B. What does the A and B mean??

I know the BH75 is a subframe mount and the Kubota web site says the B4690B is a subframe mount too. However the L3400 info mentions both and advertises "quick attach convenience and full mount subframe (BH75 only)". This leads me to believe the B4690B is either not subframe or not quick attach. The L3400 literature also says "self contained hydraulic system powered by tractor PTO (BL4690B)", does this mean the BH75 hooks into the tractor hydraulics?

Also, are the BL4690A and BL4690B the same thing? I think the B4672 is 6.5 versus the others are 7.5.

Can someone lend me some advice when comparing the different models:

1. Ease of attach/detach?
2. Self contained PTO driven hydraulics versus ???
3. Stability/power?
4. Cost?

I would guess the subframe variety would negate the MMM and the 3-point hitch variety would not.

My father in law has used the 3 point hitch variety and says that is what I should go for. Does this mean I should look at a Woods or other vender if I buy a 3400? Or are one of those a 3-point variety.

Also, the web site says something about a loader being required on teh B7800 when operating a BL4672A backhoe. Why?

I thought I was getting pretty knowledeable and now feel pretty ignorant again.
/forums/images/graemlins/confused.gif
Thanks in advance.

 

[Henro]

Wow Volnavy, Lots of questions there!

Here are few thoughts.

I believe the B7800 can use a MMM if a BL4690 is purchased. This is a 7.5 foot backhoe by the way. IF there were a choice, I would myself buy the BH75 though. Not sure if the BH75 is able to be used on the B7800 or not. I heard there was going to be a kit available to make this happen, but that could just be wishful thinking on someone's part.

The BH75 is from what I understand a 4 point mount. Much better than the 3PH 4690 in my opinion. I don't personally have an issue with using the tractor hydraulics to power the backhoe, which is what is done with the BH75. The 4690 has a pump that goes on the PTO, relatively easily, but you then have a sperarate hydraulic system to maintain.

The BH75 looks to me like a better design than the 3PH 4690. I like the way the cylinder swings the boom directly, without using a chain like the 4690 does.

I believe the A and B on the 4690 models just indicates some kind of minor revision in the hoe, but I am not sure.

Even though Kubota calls the 4690 a subframe something or other (I think they say subframe required) it really isn't. A couple existing brackets on the side of the frame are replaced with longer ones and as far as I know, that along with the installation of a heavy duty top link bracket is about all that is done to make the tractor stronger.

The 4690 and BH75 I believe are about the same in capability and both are 7.5 ft. rated. I would bet the BH75 being a 4 point attach backhoe is easiest to install and remove. But that is just a guess. I only have experience with the 4690A.

The theory is that the 4690 having an independent hydraulic system would help keep the tractor's hyd. system cleaner. But that is probably a minor issue. How many complaints have you heard about loaders not having independent hydraulic systems. Probably none. A backhoe does seem to come on and off more than a loader, but with slight care dirt getting into the tractors hydraulic fluit should not be a concern.

Don't have a clue on the cost, but since the BH75 does not need the hydraulic pump, tank, filter and fluid it may be about the same price as the 4690, or even a little cheaper?

FILs may not always know best. Myself, if I had the option, I would stay away from the 3PH backhoe. A 4 point just seems a better way to hook a backhoe to a tractor. Less likelyhood that misuse of the hoe, intended or otherwise, will result in a damaged tractor.

You need a loader for stability when using the backhoe on a small tractor. Actually, you need a loader more than a backhoe I would bet. If I had to only have one (can't cause you need the loader to safely use the backhoe) I would take the loader. But that is a moot point. You need the loader.

The loader is such a useful tool...

If I can, and if a BH75 will will be able to be fitted to my B2910, there is a good chance I will be talking to my dealer and seeing how much a trade up of my BL4690A to a BH75 would cost me. I like the thought of a 4-point sub frame backhoe that much.

Hope these thoughts help.

 

[ronjhall]

Henro has answered most of your questions. I'll try to pick up on the others.
<font color="blue"> are the BL4690A and BL4690B the same thing? </font>
I believe the A & B refer to arms that are required to mount BH on a L or B Series tractor. I don't know which one fits what tractor.
<font color="blue"> I would guess the subframe variety would negate the MMM and the 3-point hitch variety would not. </font>
The BL4690 allows the 4 caster 72" mower to be used on the B7800. When the BH75 becomes available for the B7800, MMM will be a floating type with 2 casters mounted on front of mower similar to the 60 MMM for the B7800.
There is no option for a MMM on the L3400.
<font color="blue"> Ease of attach/detach? </font>
I find my Bl4690 to be a pain to install on my B2910. Every time I do it, it gets easier. I have seen post where others have complained about their BH being hard to install. At 900 lbs the BH is the heaviest attachment that I have for the 3PH. If thing are not aligned properly it's hard to move into place.
The B7800 and the L3400 are very different tractors in size and weight.

 

[rswyan]

</font><font color="blue" class="small">( I believe the A & B refer to arms that are required to mount BH on a L or B Series tractor. I don't know which one fits what tractor. )</font>

This could be true, although my dealer told me when I ordered my BL4690B for my B2910 that the "B" designation on the 'hoe was a revision. In fact, at the time I ordered it, he told me that there would be a couple week delay until I could get it shipped to me because Kubota was just starting production on the revision "B" 'hoe. I never did find out what the revisions were over the "A" - the dealer felt they were probably minor otherwise Kubota would have been making more noise about them.

My BL4690B came with two masts (a very heavy duty top link) - one for B-series tractors and one for some other models including certain L-series.

The MMM should be pinned up before mounting the hoe if you going to leave it on (you're better off just pulling it off IMHO) - not sure that it has to be - although if you didn't, your ground clearnace would really, really suffer - since the 3PH cannnot be raised with the backhoe mounted (necessary to pin up the MMM) and the anti-lift arm on the 'hoe bolted down (you'll destroy the 3PH if you do)

The loader is required for two reasons:

1. Like Henro says, stability - the tractor would be very heavy in the rear without a FEL installed.

2. The FEL assembly provides a pair of steel rails which tie the front of the tractor to the rear - this is actually what Kubota refers to as a "subframe" - it is pretty much left permanently attached to the tractor and is not removed when you remove the backhoe or the FEL.

I'm with Bill on the BH75 vs. BL4690B - if were me and it were available I'd go with it over the BL4690B for the more rugged mount.

And I'd totally agree with Ron on it being a pain to install (I've only done twice though - so hopefully it will get easier) I almost flipped mine forward while trying to attach it to the tractor the last time - it is a very heavy thing to hold up by one's self - I almost didn't make it (literally /forums/images/graemlins/frown.gif)

Best to have someone around when you taking it on or off. I need to rework my backhoe dolly to make it easier to get on and off.

 

[Volnavy]

Wow, some great and very helpful information. I also found this tips page at the Carver site. It discusses MMM with BH.

http://carverequipment.com/backhoe__mid_mount_mower.htm

There are also some other tips on related to BH in Section E of their tips page.

http://carverequipment.com/tips.htm

It appears that the BH75 is safer, thus cost may not be an issue. If you read the tips page referenced above you will learn of an accident in which a "wonderful young local North Carolina gentleman was killed by a three point hitch mounted back hoe in 1999." What good is money if you can't spend it. Lets all be safe this new year!