Backhoe BH90 on L3940-3. Why not?

moship · Jan 30, 2017

I'm considering upgrading my tractor to a cab tractor, but hate to get rid of the BH90 backhoe I already have.

According to what I have found using the Wholegoods documents from the last few years, only the BH92 is compatible with L3x40 cabs. While the BH90 will fit non- cab GL 40's, there are footnotes stating it will not work on cab models.

Does anyone know why the BH 90 will not work?

With respect to mounting pin details and parts that would interfere with the cab. What is the difference between BH90 and BH92? Does anyone see a workaround?

Thanks in advance for your help!

Grandad4 · Jan 30, 2017

Kubota designs their backhoes to tuck in very close to the back of the tractor for strength and rigidity - very good from a safety and performance standpoint. The backhoe on my older open-station GL, for example, has the operator's seat backed right up against the tractor seat, and my head is directly under the ROPS. From what I've seen, the BH90 is also designed like that. Problem is, that's right where the back window is on a cab model GL, and there would be no room for the operator's seat (or the operator).

Evidently there were enough buyers that wanted a BH on the cab models that Kub re-designed the BH so it would work, pushing the BH and the operator's station back a little to allow more room. Don't know if they stretched just the subframe, just the BH or both, but whatever it was, it ended up being enough different that you can't play mix 'n match with the backhoes and subframes between the BH 90 and 92. I'd suppose there could be some valid engineering reasons for doing that, even though owners of the older design are kind of backed into a corner, as you describe.

buckeyefarmer · Jan 30, 2017

My bh92 for my cab has brackets to set it about a foot further back than for a non cab tractor. Bracket is on bh. If you had a non cab tractor it looks like the bracket could be removed to put the bh tighter against a non cab tractor.

buckeyefarmer · Jan 30, 2017

You can see the bracket bolted on, look behind right rear tire. You also can see the original unused pin holes, and on the far side you can see the pin on the extension bracket to the right of the empty pin hole.
My left side pin doesn't line up real well,so it takes some beating to knock that pin out. Right one comes out easy.

bdhsfz6 · Jan 31, 2017

moship said:
I'm considering upgrading my tractor to a cab tractor, but hate to get rid of the BH90 backhoe I already have.

According to what I have found using the Wholegoods documents from the last few years, only the BH92 is compatible with L3x40 cabs. While the BH90 will fit non- cab GL 40's, there are footnotes stating it will not work on cab models.

Does anyone know why the BH 90 will not work?

With respect to mounting pin details and parts that would interfere with the cab. What is the difference between BH90 and BH92? Does anyone see a workaround?

Thanks in advance for your help!

When I traded my L3430 with BH90 for a MX5800, I had the option of keeping the BH90 since it would also fit the MX. The dealer told me if I ever wanted to add a cab to the MX, I should consider getting a BH92. He said there is a cab adapter for the BH92 but not for the BH90. Since the price was right, I opted for the BH92.
My guess is the same scenario exists for your machine.

scdeerslayer · Jan 31, 2017

buckeyefarmer said:
View attachment 497076
My left side pin doesn't line up real well,so it takes some beating to knock that pin out. Right one comes out easy.

Mine was like that at first but I had the dealer pick up the tractor and fix that and the boom lock that wouldn't go into place.

moship · Jan 31, 2017

I would like to thank everyone for their feedback and photos. It's too bad Kubota didn't offer mounting kits (AKA: Adapter plates) similar to what buckeyefarmer's photo depicts for the BH90, but also understand there might be other technical reasons for not doing so.

Does anyone think these mounting kits could be adapted to the BH90 to make it work? I'm asking as I don't know anyone that has a BH92 that I could look at 1st hand.

Grandad4 · Jan 31, 2017

If it's really not possible to cross match those BH92 extension brackets to fit a BH90 and you still want to use your BH90 on a new model cab Kubota, you're going to need to get creative. For example, if you could get the measurements, the general layout, how thick those BH92 brackets are, etc., maybe a metal fabrication shop could build a "BH90 version" of the brackets for you. For example, the heavy equipment repair shops I've seen around here are constantly repairing or building replacement pieces for construction equipment, and a couple of brackets would be pretty routine stuff to them. I would expect they'd charge top $ for their time, though.

By the way, I don't know if you are anywhere near Harrisburg, but wanted to mention there is an excellent Kubota dealership in that area (Messick's, in Elizabethtown, advertiser and forum particpant here on TBN), who would know (or would probably be able to find out

) what the differences between those backhoe mounts might be. They might even have a BH92 and a new Grand L cab tractor you could examine.

buckeyefarmer · Feb 1, 2017

Pic of both sides of the bracket. Looks like the only reason for it is so the seat won't hit the cab. Looks like it would almost fit without the bracket.