Backhoe Manual thumb attachment

[tngw1500se]

I had the Mahindra thumb installed when I purchased the tractor. Unfortunately, it bent on the first day with the very first rock I picked up. In all fairness, it was a big rock and right at the limit of the dipper. Since then, I've straightened the thumb several times and it continues to get re-bent with use.

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I haven't used any heat to straighten it for fear of weakening the metal any further. Instead, I lash a five or six foot pry bar / rock bar onto the thumb and push it back into roughly the correct position. As you can see in the photos, it doesn't always bend exactly in the right spot but it's been close enough.

One day I might get around to heating and hammering it into better shape. If I do, I'm likely to weld a support bar close to the tip or perhaps a plate connecting the two tines.

I've beat the crap out of my thumb on my Max 22 without damage other than paint.

 

[AchingBack]

For $355.00 including shipping, I am very pleased with my weld-on manual thumb, installed on my 2615, 3710 backhoe. It is very stout. Notice the solid flat plate bracing the jaws. No too much change of bending.

 

[MRCONCDID]

I had the Mahindra thumb installed when I purchased the tractor. Unfortunately, it bent on the first day with the very first rock I picked up. In all fairness, it was a big rock and right at the limit of the dipper. Since then, I've straightened the thumb several times and it continues to get re-bent with use.

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I haven't used any heat to straighten it for fear of weakening the metal any further. Instead, I lash a five or six foot pry bar / rock bar onto the thumb and push it back into roughly the correct position. As you can see in the photos, it doesn't always bend exactly in the right spot but it's been close enough.

One day I might get around to heating and hammering it into better shape. If I do, I'm likely to weld a support bar close to the tip or perhaps a plate connecting the two tines.

I would weld a thick wall metal round or square bar between those to teeth, and while your there you could plate them as well for more strength.
MrC.

 

[BGSnow]

I had the Mahindra thumb installed when I purchased the tractor. Unfortunately, it bent on the first day with the very first rock I picked up. In all fairness, it was a big rock and right at the limit of the dipper. Since then, I've straightened the thumb several times and it continues to get re-bent with use.

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JoeyDude - New guy here, so excuse diggin up an old post, but thats what us new guys do as we absorb information.

How thick is the steel on you teeth tines?

 

[JoeyDude]

How thick is the steel on you teeth tines?

The steel is 1/4" thick but I think the issue is that the teeth were over 4" long from the last support / crosspiece / gusset. Maybe they were closer to 5" long but it's hard to tell now that they are mangled. It doesn't take tons of pressure to bend the steel sideways at that length, particularly if it's low grade steel.

Note that my straightening procedure is to lash a 6 foot long pry bar onto the teeth of the thumb and press hard with hand / body pressure. It's far from perfect for straightening the teeth but it's better than nothing. Removing the thumb and putting it into a press would probably work a heck of a lot better.

My plan is to replace the entire assembly with an aftermarket unit. I've been talking to a manufacturer and there might be a better option. If it pans out, I'll post on the forum.

 

[downsizingnow48]

Plate between the tines is an obvious and simple fix. Also consider doubling up on the tines. Just a few dollars of steel and a few minutes of welding.

 

[Navasot]

Yeah im not sure why they do open tined teeth guess to let dirt through... never been a fan of fixed thumbs anyway hope you get it sorted out

 

[JoeyDude]

Plate between the tines is an obvious and simple fix. Also consider doubling up on the tines. Just a few dollars of steel and a few minutes of welding.

It's a simple fix when it's brand new. Not so much after it's been bent, straightened, bent, straightened, bent, straightened... It's time to replace with an upgrade.