Disc harrow restore/conversion to 3-point

Chilly807 · Oct 1, 2011

Earlier this year I came across these old 8 foot Massey Harris disc harrows, they were a set of pull-behind double harrows that had been slowly rusting away behind a friend's garage.

We worked out a trade, and now I have a project to convert them to a 3 point type. All the gangs of discs turn freely, which is a real plus.

I considered converting them to rigid frame tow-behind, with a linkage system and hydraulics to raise and lower, but that would have meant buying wheels and tires, plus at least one cylinder and hoses.

All I plan to do with them is an occasional pasture re-work, plus yearly vegetable gardens for us and a couple of neighbours, so extensive re-building didn't make much sense.

I'm going to use the front set only, and either keep the rears for a source of spare parts or sell them off if the fronts work well after the conversion.

I bought a bit of steel yesterday to get started, and although it hasn't been that long since I did that, the price still shocked me.. nothing is getting any cheaper, it seems.

I'll post as the job goes along, it'll likely take a few weeks as the weather allows, not to mention the time factor. What with building a barn this summer, seeing these sitting there waiting for attention has been gnawing at me.

Sean

Chilly807 · Oct 3, 2011

Yesterday I cut the 3-point cross tube and top link post, then welded them in place. The pins for the 3-point hitch will be bolted through pieces of 1/2 inch steel welded inside the ends of the cross tube. I used 3 inch square tube with a 1/4 inch wall thickness. Probably overkill, but I really doubt I'll bend it.

The only way to tighten the bolts is to cut an access hole in the bottom of the cross tube big enough to get a box-end wrench on the ends of the pins. I thought briefly about simply welding the pins in place. Very briefly. I'd like to be able to remove and replace them if necessary without grinding and re-welding.

The next step is to get the end caps cut to size and the 7/8 holes cut, then weld them in place and install the pins. I also need to decide what size to make the fork for the top link post.

Sean

Chilly807 · Oct 4, 2011

I got the end caps and top link forks welded in place and the holes cut.

The Cat 1 pins were a little longer than I needed on the threaded ends, so they got shortened by about an inch.

I doubt I'll get much more done until the rain stops and I can work outside again. Ophelia has been pretty generous with rain.

Sean

Kyle_in_Tex · Oct 4, 2011

I'm watching out of envy of your rain puddles.

Keep on posting. Are you going to shorten the tongue so it won't be so far back?

Chilly807 · Oct 5, 2011

It's raining cats and dogs here again this morning, I'd part with some.. no charge.

I hadn't given too much thought to shortening the tongue, but you've got me thinking. I am going to shorten it slightly, to just in front of where the sliding adjustment collar is now. To make it any shorter and still get full adjustment I'd have to shorten the side rails and re-cut the locking holes in the tongue.

Having said that, it's not so much work, and it would definitely make for a more compact (easier to lift) package. The L3400 is rated for 2000 lbs lift capacity at the pins, and 1400 lbs 24 inches back from that. It has no trouble with a 700 lb rotary cutter, but if I add some serious weight to the harrows it may be a problem.

I'm thinking these weigh about 300-400 lbs as they sit, and I'm adding at least 100 lbs more steel with the new frame. If the finished product was shorter or at worst no longer than the cutter it should be fine, even with a few hundred pounds of ballast. The weight distribution will be different, too.

It'll definitely be an implement I'll leave the FEL attached when I use it.

Sean

Chilly807 · Oct 28, 2011

It's done except for paint... too wet here to really try it out, so it'll have to wait for spring.

I did end up shortening the frame by about 15 inches, the Kubota wasn't really happy about lifting it... no problems at all now.

The frame is designed to lend stiffness to the harrow while it's being moved, the adjustment rails on the sides are free to move back and forth, sandwiched between the main frame and the lower supports. The top strap is 1/2 x 3 flat bar to carry the weight on the 3 point.

I added the rear post and stay chains for those big bumps you just don't see coming going across a field or down the road.

Sean