Backhoe Thumb

[Hazel]

Does anyone have a copy of the Mahindra Emax20S installation instructions for the Backhoe Thumb? There wasn’t any in the box and Mahindra doesn’t have them either
Thanks for any help you are able to give me…

Rick

 

[arrow]

Does anyone have a copy of the Mahindra Emax20S installation instructions for the Backhoe Thumb? There wasn’t any in the box and Mahindra doesn’t have them either
Thanks for any help you are able to give me…

Rick

Perhaps this will help. I've put together plenty of these so if you have any further questions feel free. One thing I would offer is to not hit the pivot pin with a steel hammer as opposed to a plastic hammer to get it thru. You can also use a drift placed at the center of the pin to knock it in.
Some of these pins are tough to get thru and some pins just slide in. Hope you get a "slider"
watch

 

[Hazel]

Hi Arrow,
Thank You very much for your response, the video was great. The only question i have is there any Torque specifications for the bolts or do I use a general Torque spec from a chart.
Thanks again for the help
Regards,
Rick

 

[arrow]

You're very welcome. Chart torque specs will be fine.
The biggest bugaboo for these are the placement of washers between frame for pivot pin..
If yours is as such, you would have received several million of them to place between the rails.
The trick is to get as many as you can on the thru end and i use a needled nose to sneak them in, one at a time.
You will get eventually to the point of having only a two washer space to place them in and if you pull the pivot pin out to get those last few in, you'll end up losing them all. My first attempts were rather maddening with this set up. I used gum, grease, another rod coming in from the other way, a drift and ended up simply finessing them in one at a time.
You'll see what I mean if yours comes with the washers.
If it doesn't, cut your self some bushings out of steel pipe as there would be too much side movement otherwise.
Bushings would have been much easier to place if they thought about that from the factory.

 

[Hazel]

Here’s a few photos of the Mahindra Mechanical Thumb

 

[arrow]

Here’s a few photos of the Mahindra Mechanical Thumb

Great!.
They may have changed their manufacturer source. Different set up that once necessitated a bunch of washers to contain side flex.
Your pins do not look oversized for their sleeves either like some of the ones i assembled.

Big time saver.

 

[Hazel]

Hi Arrow,
I forgot to include the photo of the large pin to the bucket… I noticed it has a small chamfered hole that does not go all the way through the rod. What’s that for, Maybe to index shaft to line up bolt hole?
I’m assuming the other pins that have the flat heads don’t require washers on the head side?

 

[arrow]

No, the flat head acts like a washer but you can still put a washer on there if the tolerances allow.
Some have this hole and some don't. I'd ignore it for now.
Some say its for a "pivot pin removal tool" in case the pivot pin ever gets stuck or rusted in place. Insert the tool and wiggle it till the pin breaks free. How that gets done when a mounting sleeve is in the way is beyond me.
I can't give you a definitive answer however because I don't know why its there. I've heard all kinds of stories so I'll change this post to reflect more of my truth.
I'd just be guessing and I don't tolerate well when people don't know and they just guess so I'm not gonna do such to you.

 

[Hazel]

Thank You Arrow… I apologize if I have been a pest with all my questions however, your responses have been extremely helpful to me. Rick

 

[arrow]

Thank You Arrow… I apologize if I have been a pest with all my questions however, your responses have been extremely helpful to me. Rick

Heck no. Please no apologies needed. i consider it an honor to help.

 

[Buggs67]

I finally got the thumb welded on. It was 60 yesterday and I wanted to do it outside in the full sun. First I had to drade the driveway/lane and that ate time but I got it well tacked on and tried it out.

I took these at night with a flash so it may be hard to see but the thumb is a little too long (This is the 24"); about 4". My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole. That would preserve the last tooth which extends a little further than the other teeth. But that would also move the connection of the crossbrace up higher unless I also redrill a hole for it to connect to the thumb.

The upside of all this cutting/drilling is I can somehow align the holes on the mount and thumb so there would be a storage position which is currently missing. As others have remarked you have to use a bungee cord such to secure the thumb up out of the way or remove it entirely.

Another possibility is taking 1" off the bottom and 3" off the top. That would move the attachment of the crossbrace to the thumb only 3". BTW my BIL has a nice steel band saw to do the cutting and my neighbor/friend has a full machine sop so he'll drill the holes in the correct location.

If you look close or zoom in you can see my half-ass welds. I used my Titanium 125 w/.035 FC wire which is only rated to 3/16" and the mount is 1/2" and the dipstick is 1/4" or more. I'll finish burning it in when all is said&done. I tried to pick up a 36" long log and the overextended teeth made it harder. But it did pick it up (4-6 times).

Any advice would be appreciated.

 

[arrow]

I need some enlightemnment.
I have never seen a bolt on mechanical thumb needing welding to the boom. I guess yours didn't have the drilled ears toward the top of the boom to fit the upper pin in?
Who makes this one?

 

[AchingBack]

I finally got the thumb welded on. It was 60 yesterday and I wanted to do it outside in the full sun. First I had to drade the driveway/lane and that ate time but I got it well tacked on and tried it out.View attachment 734667
I took these at night with a flash so it may be hard to see but the thumb is a little too long (This is the 24"); about 4". My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole. That would preserve the last tooth which extends a little further than the other teeth. But that would also move the connection of the crossbrace up higher unless I also redrill a hole for it to connect to the thumb.

The upside of all this cutting/drilling is I can somehow align the holes on the mount and thumb so there would be a storage position which is currently missing. As others have remarked you have to use a bungee cord such to secure the thumb up out of the way or remove it entirely.

Another possibility is taking 1" off the bottom and 3" off the top. That would move the attachment of the crossbrace to the thumb only 3". BTW my BIL has a nice steel band saw to do the cutting and my neighbor/friend has a full machine sop so he'll drill the holes in the correct location.

If you look close or zoom in you can see my half-ass welds. I used my Titanium 125 w/.035 FC wire which is only rated to 3/16" and the mount is 1/2" and the dipstick is 1/4" or more. I'll finish burning it in when all is said&done. I tried to pick up a 36" long log and the overextended teeth made it harder. But it did pick it up (4-6 times).

Any advice would be appreciated.
View attachment 734666

Looks just a tad too long. Hope it works well, though.

 

[monkeyman9]

I finally got the thumb welded on. It was 60 yesterday and I wanted to do it outside in the full sun. First I had to drade the driveway/lane and that ate time but I got it well tacked on and tried it out.View attachment 734667
I took these at night with a flash so it may be hard to see but the thumb is a little too long (This is the 24"); about 4". My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole. That would preserve the last tooth which extends a little further than the other teeth. But that would also move the connection of the crossbrace up higher unless I also redrill a hole for it to connect to the thumb.

The upside of all this cutting/drilling is I can somehow align the holes on the mount and thumb so there would be a storage position which is currently missing. As others have remarked you have to use a bungee cord such to secure the thumb up out of the way or remove it entirely.

Another possibility is taking 1" off the bottom and 3" off the top. That would move the attachment of the crossbrace to the thumb only 3". BTW my BIL has a nice steel band saw to do the cutting and my neighbor/friend has a full machine sop so he'll drill the holes in the correct location.

If you look close or zoom in you can see my half-ass welds. I used my Titanium 125 w/.035 FC wire which is only rated to 3/16" and the mount is 1/2" and the dipstick is 1/4" or more. I'll finish burning it in when all is said&done. I tried to pick up a 36" long log and the overextended teeth made it harder. But it did pick it up (4-6 times).

Any advice would be appreciated.
View attachment 734666

If i were you, I'd cut off the last few teeth with a grinder and cutting wheel. Then grind some deeper teeth in later if you really think you need to. Much easier and no messing with holes.

 

[rdinatal]

My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole.

Hmmm, check for clearance in every position.
(If not already, multiple times)

 

[rdinatal]

I have a job to really utilize and work the BXpanded thumb this weekend. Moving large rocks, stumps, etc.

Will post some pics, if I remember....

 

[Buggs67]

Hmmm, check for clearance in every position.
(If not already, multiple times)

I ran it back and forth after he first 4 tacks. All good, just too long.

 

[Buggs67]

I need some enlightemnment.
I have never seen a bolt on mechanical thumb needing welding to the boom. I guess yours didn't have the drilled ears toward the top of the boom to fit the upper pin in?
Who makes this one?

It's not a bolt-on. It's designed to weld to the dipstick. I guess I could've drilled the mount in 6 places and then drilled and tapped the dipstick and bolted it up.

It's by Titan attachments the 24" size. It was about $164 plus tax. They also make a 36" for larger machines. And a smaller clamp-on style for small machines like a BX (it's made in China and available everywhere it seems); but it only fits dipsticks up to 5" wide iirc..

 

[Buggs67]

If i were you, I'd cut off the last few teeth with a grinder and cutting wheel. Then grind some deeper teeth in later if you really think you need to. Much easier and no messing with holes.

That is the easy way. I'm gonna consult with my machinist friend.

The real drawback with this thumb is that it has no storage position, you know, like just rmoving one pin and swinging it up to the dipstick and reinsterting the pin.