Backhoe 485 hydraulic thumb

[SwLWildcat]

Hello; New to the forum today. I just purchased a 2012 JD 4720 yesterday with the 400CX and a 485 backhoe (the backhoe is 2 weeks away) as well as a bunch of other attachments. I plan to develop an acerage for us with this unit. I have run lots of heavy equipment in my time and I like to have a hydraulic thumb on my stick (dipper). I know JD sells a mechanical thumb for this unit, however I am not interested in this set-up. Has anyone installed a hydraulic unit on one of these? I am a heavy equipment mechanic by trade so I have no issues with making something else fit. I am just wondering if anyone has used another manufacturers thumb as a starting point? If not I will just start fabing something up.

 

[beenthere]

:welcome: to the forum.
I'd be interested to see what you have in mind. Can you add hydraulics to the mechanical Deere set-up? Any pics?

 

[SwLWildcat]

I am not sure if the mechanical thumb would pivot properly. I would be nice if they had a wedge set-up to change buckets as well. I have an old IMAC thumb/cylinder off a Komatsu PC-200 laying outback, but that is like hunting squirrels with a 10 gauge... I don't think John Deere makes these backhoes, Bradco does. I sent them an e-mail to see what they have available.

I got a good deal on my tractor and attachments from my local dealer (cost). So I have to assemble everything as there is no money in the deal for them to do any assembly. With that said I am not sure yet as to how they plumb in the back-hoe as it won't be here for 2 weeks. I believe they break the tractors main hydraulic circut and plumb the 485 in series, but I could be wrong. Once the unit gets here I will know more...

 

[ORCM]

I am not sure if the mechanical thumb would pivot properly. I would be nice if they had a wedge set-up to change buckets as well. I have an old IMAC thumb/cylinder off a Komatsu PC-200 laying outback, but that is like hunting squirrels with a 10 gauge... I don't think John Deere makes these backhoes, Bradco does. I sent them an e-mail to see what they have available.

I got a good deal on my tractor and attachments from my local dealer (cost). So I have to assemble everything as there is no money in the deal for them to do any assembly. With that said I am not sure yet as to how they plumb in the back-hoe as it won't be here for 2 weeks. I believe they break the tractors main hydraulic circut and plumb the 485 in series, but I could be wrong. Once the unit gets here I will know more...

Just curious what is the dealer cost on a 485?

 

[SwLWildcat]

MSRP up here is over 10K. I paid just under 8K with all the accessories.

 

[sunnyside360]

I paid exactly $8K for my JD 485 BH 2 yrs ago and the dealer assembled and set it up. Did the work I wanted to get done and haven't used it much since. Probably should have rented a BH instead of buying it.

 

[AKfish]

I am not sure if the mechanical thumb would pivot properly. I would be nice if they had a wedge set-up to change buckets as well. I have an old IMAC thumb/cylinder off a Komatsu PC-200 laying outback, but that is like hunting squirrels with a 10 gauge... I don't think John Deere makes these backhoes, Bradco does. I sent them an e-mail to see what they have available.

I got a good deal on my tractor and attachments from my local dealer (cost). So I have to assemble everything as there is no money in the deal for them to do any assembly. With that said I am not sure yet as to how they plumb in the back-hoe as it won't be here for 2 weeks. I believe they break the tractors main hydraulic circut and plumb the 485 in series, but I could be wrong. Once the unit gets here I will know more...

I had a home-fabricated mechanical thumb on a JD970 (33hp). It had 3 positions - ~45 degrees to the dipper; ~90 degrees to the dipper and flat up against the dipper for storage.

Presently, I've got a hydraulic thumb on a JD110TLB. The hydraulic thumb is very convenient and I wouldn't own a backhoe or excavator without a thumb - IMO. That said, the mechanical thumb really does about 90% of the same work that the hyd thumb does.

If I knew ahead of time on a job that the thumb would be needed for nearly everything - stumps, logs, brush, etc. - I would put it in the 45degree pin setting. Or, if I would have to do a fair amount of digging and only a few stumps or debris - I'd use the 90degree setting. The thumb was out of the way for digging but available to clamp onto things when needed.

So.. before you go all out and commit to buying parts; I'd wait and use the mechanical thumb for a bit and then decide from that point. If you're pretty savvy on equipment - you'll figure out a way to utilize the mechanical thumb and make some adaptations for incorporating a hyd cylinder, etc. As long as the thumb cylinder pressures (reducing spool valve) are less than the main system pressure - when you curl the bucket against the thumb - the thumb just backs up. And the mechanical thumb will not be constructed of materials that are considerably heavier duty than either the dipper or the boom and might cause stress failures for those "downstream" components.

AKfish

 

[GreatWhitehunter]

The mech thumb for the 485 goes on the bucket pin so all you'd need to do is buy the thumb and pin and fab up a mount for the hydro cylinder. I was thinking of using a electro/hydro setup for thumb control. There's an outfit called Northsaw that I've tried contacting about building a pin on hydro thumb. Unfortunatly the guy is bad with emails and I haven't followed up. I also looked into adding a foot pedel setup like the 110 has.

Matt

 

[SwLWildcat]

Thanks Matt;

Building pins is quite easy. Just pull the pin you have and measure it, or take it to the local machine shop and tell them what you want. They will measure your pin and make a new one with whatever additional material you want on the ends. The important thing is to specify the material you want it made out of. Use 4140 or 4340. 4140 is great material and fairly easy to work with, and would be equal to or greater then OEM spec material. This material comes in nominal sizes in both standard and metric so it's just a simple matter of cutting the material to the correct length and machining the ends with a tapper, etc. If the end has a boss you just spin one out and weld it on. I have not seen a 485 yet so I can't comment on how I would plumb it. If the control valve under the seat has sections bolted together then I would just get another section and a set of seals, and tie bolts 1 section width longer then the existing bolts. Split the control valve, and add the section. The question is will it all fit back under the seat... The section should have relief valves built in so it's just a simple matter of backing off the reliefs so that when you curl the bucket the thumb will go over relief and slowly move. The other option would be a diverter valve off a stabilizer, but then you have to use the stabilizer leg pressure for the thumb, or install some in-line reliefs. Personally I would prefer a dedicated section, with an electrical switch on the joystick.

Sunnyside I also got the creep to reposition kit and a second bucket for the $7900. The second bucket was used a bit, but looks like new, other than the paint. I guess I should have clarified what I meant by accessories.

 

[GreatWhitehunter]

Thanks Matt;

Building pins is quite easy. Just pull the pin you have and measure it, or take it to the local machine shop and tell them what you want. They will measure your pin and make a new one with whatever additional material you want on the ends. The important thing is to specify the material you want it made out of. Use 4140 or 4340. 4140 is great material and fairly easy to work with, and would be equal to or greater then OEM spec material. This material comes in nominal sizes in both standard and metric so it's just a simple matter of cutting the material to the correct length and machining the ends with a tapper, etc. If the end has a boss you just spin one out and weld it on. I have not seen a 485 yet so I can't comment on how I would plumb it. If the control valve under the seat has sections bolted together then I would just get another section and a set of seals, and tie bolts 1 section width longer then the existing bolts. Split the control valve, and add the section. The question is will it all fit back under the seat... The section should have relief valves built in so it's just a simple matter of backing off the reliefs so that when you curl the bucket the thumb will go over relief and slowly move. The other option would be a diverter valve off a stabilizer, but then you have to use the stabilizer leg pressure for the thumb, or install some in-line reliefs. Personally I would prefer a dedicated section, with an electrical switch on the joystick.

Sunnyside I also got the creep to reposition kit and a second bucket for the $7900. The second bucket was used a bit, but looks like new, other than the paint. I guess I should have clarified what I meant by accessories.

I'm aware that building a pin is not any real hurdle. But I'd mostlikely just buy the deere pin. I looked into ganging another valve onto the manifold. I didn't think the room was there. I'm suprized Deere didn't just address this themselves. I almost went with the Woods hoe over the 448 just for the hydro thumb option. It would have take nothing to make that an option on any of there hoe's. The woods unit also has throttling valves for the swing if I recall. But the 448/485 mounting and fit is what sold me over the woods.

It's funny I don't see the thumb listed on deere's site as an option and a local dealer wasn't even aware it was an option. Deere's consumer product marketing needs a kick in the rear. And there IT team need to be fired for there website.:ashamed:

Matt