Pics of IH #3 potato planter partially disassembled

[Bunchgrass Farm]

So in my quest to fix the planter, which seems to be kicking out the slip clutch at random moments, I tore into it and was able to discern how the whole slip clutch assembly goes together. I'm thinking I can use a few shims to tighten things up and keep the clutch from slipping so easily (like one potato can cause it).

Planter

Right side axle. Main drive gear removed.

Left side axle. Picker finger drive gear.

Picker finger drive gear showing drive engagement.

 

[K-Mo]

The "slip clutch" is located on the forward most shaft. It has 3 bolts with 3 springs.
I believe what you have is a drive coupling not a slip clutch. Your pictures don't show the mating side of the sprocket. Does it have "notches" to fully engage with the picker shaft "finger"?
The sprocket should fully engage with the finger on the picker shaft.
If the sprocket is badly worn, the engaging notches made need to be built up to mate with the picker shaft. If the sprocket is just backed away from the picker shaft, you may be on the right track to add shim washers.
If you don't have a manual, you can get one from Binder Books.
Binder Books