Turning a 5-Shank Chisel Plow into a 7-Shank Workhorse
Today’s mission was simple: get more out of the equipment we already own.
That meant upgrading a five-shank chisel plow into a seven-shank chisel plow—without buying new, without getting fancy, and without overcomplicating it.
If you’re running a small farm or homestead, this kind of mindset matters. Equipment is expensive. Ingenuity is not.
Let’s get to work.
The Goal
The objective was to add two additional shanks to an older five-shank chisel plow and set it up to break through heavy compaction before planting. One pass. That’s all this tool needs to do.
Step 1: Sourcing the Shanks
I picked up an old, weathered chisel plow and salvaged two usable shanks from it. These weren’t pretty. They were rusted, beat up, and had been sitting outside for a long time—but they were solid enough to serve their purpose.
That’s the key distinction:
functional beats perfect when you’re building a working farm.
Step 2: Winning the Battle Against Rust
Old bolts and rusted hardware can derail a project fast.
The night before, I sprayed all six bolts with white lithium grease from WD-40. I’ve used it before, and it works incredibly well for penetrating rust.
Even then, some bolts needed persuasion:
-
White lithium grease
-
A punch (one that belonged to my dad—still doing its job decades later)
-
A 16-oz hammer
-
And when needed… a 12-lb sledge
Rust eventually loses when you’re patient and persistent.
Step 3: Swapping and Reusing What Works
One shank had a broken point, so I pulled a better one from the donor plow and swapped it over. No sense buying new when a serviceable part is already sitting there.
The points I’m running are:
-
3 inches wide
-
45° angle
-
Designed to both penetrate and turn soil
That angle matters. It doesn’t just cut—it fractures compaction.
Step 4: Mounting the New Shanks
Once the shanks were free:
-
I test-fit the old bolts on the John Deere frame
-
Confirmed sizing
-
Snugged everything down evenly before final tightening
By the end of this step, the transformation was complete:
five shanks became seven.
Step 5: Setting Working Depth
Next came dialing in depth using the guide wheels.
Target:
-
Ideally 8–12 inches
-
Deep enough to break compaction past the hardpan
-
Not so deep that we waste horsepower or fuel
With the guide wheels set at 10 inches, real-world depth should land right in that sweet spot once the plow is under load.
Why This Upgrade Makes Sense
Around here, chisel plows in this condition typically sell for about $150 per shank.
-
Original purchase: ~$750 (five shanks)
-
Added value from two shanks: ~$300
-
Estimated resale value now: ~$1,100
That’s a meaningful upgrade using mostly sweat equity and used parts.
The Bigger Lesson
This mission wasn’t just about steel and bolts.
It was about:
-
Stretching dollars
-
Respecting old equipment
-
Making tools earn their keep
-
And proving that small farms don’t need new—they need thoughtful
If you’ve got an older chisel plow and want to get more out of it, this is one proven path.