Change The Game With A Backhoe Thumb
My backhoe thumb installation adventure

Reading Time: 5 minutes
A backhoe thumb is something I’ve always wanted. Unfortunately, just like it took me years to add tractor bucket hooks to my John Deere, it’s a project that was lost to the depths of time, endlessly delayed by “I’ll get around to it” just like my snowplow tractor bucket attachment I have yet to build. But finally, the stars have aligned, and I’ve found one of those rare “round-to-it” things I needed.
Backhoe Thumbs
But why a backhoe thumb? We’ve had a three-point backhoe for our John Deere 5105 for over 20 years, and it does its job, but nothing else. A regular backhoe is excellent for digging holes, but that’s about it. What if you could use it to process wood, rip up brush, or stack rocks? That’s where a backhoe thumb makes the difference.
OEM Vs. Aftermarket
Some manufactures offer their backhoes with integrated thumbs or sell upgrade kits to add a backhoe thumb. Since these kits are product specific, they provide better integration, operability, and easier installation. Of course, convenience is expensive. If you’re on a budget, the aftermarket has a slew of “universal” fit backhoe thumbs for less. These require more fitting work on your part, but the price is right.

Hydraulic Thumbs
If you want the most from your backhoe thumb, you’ll want to consider a hydraulically operated thumb. A hydraulically operated thumb gives you immediate fine adjustment of the thumb position from the operator’s platform and adds a degree of speed and ease. The downside to these units is the cost because they include parts like a piston and controls. Additionally, added components also mean added weight. On large excavators, this may be trivial, but a hefty thumb on three-point attached backhoes can significantly reduce your lifting capacity.
Challenges
If you’re buying a backhoe or excavator with a hydraulic thumb already installed, you’ll love the added functionality. If you’re adding a hydraulic thumb to an existing machine, be prepared to invest more time and effort. Adding new hydraulic lines and controls is also seldom a quick project.
Mechanical Thumbs
Mechanical thumbs are the simplest and cheapest thumb you’ll find on the market. Manual backhoe thumbs are simple pin-in-place devices. If you want to change the angle of your thumb or deploy it, you need to exit your operator’s platform and engage it manually, which can make it cumbersome.
Attachment Method
Both hydraulic and mechanical thumbs come in bolt-on and weld-on configurations. Some can be modified to be either, but most are one or the other. Bolt-on kits simplify the installation for those who don’t have a welder, but welding offers the sturdier, more permanent attachment. Weld-on thumbs may also save you on weight, which is a consideration for compact tractors.

Sizing
Beware that not all backhoe thumbs are right for your machine. Purchase the correctly sized thumb for your application, or you risk damaging your machinery. To find out what size thumb is right for your use, move your bucket to the ninety-degree position. Measure from the inside of your backhoe arm to the tips of your bucket’s tines, or to where they roughly used to reach if they’re worn. That measurement is the minimum thumb length for your machine. A thumb shorter than that runs the risk of bending and damaging your backhoe arm.
My Scenario
I couldn’t justify the time or expense of a hydraulic thumb, nor was I interested in paying for name-branding, so I looked to the aftermarket to find the right mechanical thumb for me. Our backhoe is a three-point attachment, but it is a category two unit with plenty of force and a forty-eight horsepower tractor behind it, so I wanted a stable, well-built thumb. Since I have the equipment, I opted to weld this thumb to my backhoe for simplicity. I ultimately bought my thumb from Linville Industries, opting for an American made product that’s a bit more robust than some cheaper imports I was finding on the web.
Prep work
I removed the paint from my working surfaces, ground the welded seam on my backhoe so my new thumb attachment plate would sit flush and cleaned all welding surfaces with alcohol to remove any contaminants. However, I did not grind down to bright steel on my backhoe, which I now regret.

Welding
I used my Millermatic 220 MIG welder to attach my new thumb, which might not have been the best welding type to use. The thick steel was a bit much for my machine, and it took three passes to weld it up. Looking back, I think I should have used my old tombstone ARC welder, and it would appear that the visual quality of my welds suffered greatly from residual mill scale I didn’t grind off. Regardless of my errors, the thumb is stuck on there for good.
Functionality
So far, I’ve put over 50 hours on this thumb, and I have yet to feel the need to fold it away or reposition it. I have found the need to upgrade my pins to lynch-style pins, so every other day doesn’t turn into a search party. It’s taken a little getting used to, and it’s not the same as using an actual excavator, but it’s undoubtedly a useful tool to have.

Real World Use
I find my lack of reach with my particular machine, and the fact that I can’t move like a tracked excavator is a disadvantage. However, I won’t be buying a real excavator anytime soon, so this arrangement will suffice. If it’s shrubbery you’re after, I’ve found you’ll have to go for the roots, since small branches slip through the tines.
The Verdict
Aside from the welding not being my best work, I’m pleased with the addition of a mechanical backhoe thumb to my tractor. The new addition has undoubtedly changed the way I use my tractor, made short work of otherwise tiring jobs, and has made a significant impact around the homestead. If you own a backhoe attachment or excavator that does not have a backhoe thumb, I suggest you invest in one. For a small farm or homestead, the price paid for the functionality gained is on point, but for a commercial user, a mechanical thumb may not fit the bill.
Do you have a thumb on your backhoe? Are you considering adding one? Tell us all about it in the comments below!
Originally published in Countryside and Small Stock Journal’s special Hands-On Homesteading 2020 issue and regularly vetted for accuracy.