Mowing Old Case rotary mower question

n9viw · Apr 9, 2009

Hey all, first post! Hope you can help.

I recently purchased a '49 Farmall 'M' with a decrepit 3-point (Class 1 or 2) 6-foot rotary mower. The mower needs at least one new blade; I could get all four new ones, but I could also hardface and refinish the three that aren't broken and save some money.

Wait, FOUR blades? Yes, and there's the problem that prompts my request for help. I've never seen a rotary deck with four blades, and neither has anyone else I've talked to, so I have no idea what I have here!

This mower looks half-homemade, but there's enough solid engineering here to show that it isn't ALL homemade. There are solid rivets, factory welds, and other polished fitments (good clean welds, etc) enough to show that. There are, of course, the plethora of booger welds, poor fitup, and spare bits bolted or welded on to 'make do' that shows it's been 'customized' in the past.

That said, the unit has a Case gearbox, and that's all the identification it has. The deck is essentially raw steel, there are no stickers, plates, or emblems anywhere on it. The gearbox bears, in addition to the usual instructions regarding PTO speed and filling locations, the mark "485CH". This is on the right side, directly above the arrow pointing to the fluid level check hole, below which is the mark "S.A.E. 140", which obviously means 140-wt gear lube. I don't know if the "485CH" indicates a fluid quantity, or (more likely) is a part number for the gearbox itself.

The only other cast part on it is the trailing wheel housing, which bears the mark "TB1102" on the right side. It is attached aft of the deck by a square boom made from two pieces of 2" angle steel forming a square tube and welded along the seams. The welding is good, but I don't think it's good enough to be factory, as I'd think the factory would use solid square stock, or rolled and welded square tubing... if such existed when this thing was made.

As I mentioned before, the unit has FOUR blades. The blade carrier is shaped like an "X", with the output shaft of the gearbox intersecting the center of the "X". The ends of the carrier consist of two plates, one above and one below the blade, so the blade is sandwiched between them.

There is a blade at each end of the "X", held in place by a shoulder bolt, what we used to call "Axle bolts"- the area on which the blade rides is a larger diameter than that which a nut threads on. The heads of the bolts are 1-1/4" hex, and the nuts are 1-1/8" castellated to interface with the cross-drilled holes in the threaded shanks of the bolts. Some previous owner replaced a shoulder bolt with a standard bolt, which wore a 'waist' into the bolt. Another of the shoulder bolts was tightened too much, which caused the blade to wear a notch into one side, almost halfway through by now.

The blades themselves are 1/4" high-carbon steel, 3" wide and 18" long, with two cutting surfaces each to allow the user to flip the blade over for greater longevity. There are three square holes in each blade (in addition to the mounting hole), which a local welder informed me was so the user could bolt on a 'fin' to affect the way the grass was agitated under the deck... an early mulching feature? These blades are not pitched at all- they're just flat plate steel with the cutting surfaces ground on both edges of the blade, for about half the blade's length.

One of the blades has broken off at the third hole, just about at the halfway point, closest to the mount. The difference in weight between it and its opposite blade causes a vibration that shakes the whole deck. I had gone to the welder to ask if he could weld on a new piece of plate to reform the blade, but he told me it wouldn't last, because a) welding on high-carbon steel hardens it further, causing it to crack and potentially break NEXT TO the weld, and b) he'd have a hard time balancing it to its opposite, so I'd likely still have a vibration.

He recommended trying to find replacement blades for it, but so far I've not had luck, as I cannot find a name/number plate on this unit ANYWHERE. I was told there should be a stamped steel or cast iron plate riveted to the frame near the gearbox, but I have not found a thing. (I did find, however, that it is definitely a Case, and the decking is original- the color of the paint I found under the grease on the gearbox is identical to the color of the paint I found under the grease on top of the deck AROUND the gearbox, and it's definitely Case Orange.) Most places just tell me to bring the blades in, and they'll try to match them up to the closest reasonable facsimile they can find.

I'll likely go this route, and have no worries, but I still want to know, WHAT IS THIS THING?! I can post pics if anyone thinks it would help.

TIA!

Nick

n9viw · Apr 9, 2009

I just got off the phone with a fellow over at a local machinery reselling place. He said that 1/4" thick flat blades sound awfully thin (!!), that most of his stuff is 3/8" on up to 1/2". He also said that he had seen some 4-blade mowers, most of them were made in the 50s, but that it sounded more like a stalk chopper than a mower. This may make sense, as the front of the deck has two upraised sections with rubber flaps on them, perhaps those are the spacing for corn rows?

If this is the case, can this unit be pressed into service as a grass mower, or would I be better off refurbing it and selling it or trading it for a grass/brush mower?

Nick

n9viw · Apr 18, 2009

Wow, such a silence ought to have an echo! Does anyone still chat here?

I went to the old reseller, who verified that what we had was indeed an IH stalk chopper, likely made back in the late 40's or early 50's. Unfortunately, he was not able to match any of his stock to my blades. Instead, we purchased a pair of pitched and offset grass blades, which had huge mount holes. He also sold me the bushings to fit the blades, and a pair of bolts with nuts to install them.

I just went to install them today, and discovered three things wrong:
1) The offset on the blades is so extreme, even if the blades leveled out during operation, the grass would only be 1" long.
2) The spacing between the mount plates is wider than the bushing, so I'd have to seriously compress the plates (and each 1/4" thick? Not likely) to capture the bushing and keep it from getting spit out from under the blade.
3) The blades are longer than my old ones, which means that once they spin up, they could easily hit the deck.

Needless to say, those are going back. I used the best two of the four old blades, and the best two of the four old bolt and nut sets, and mounted them to the chopper. I took the mower out for a drag, and tried it out on the grass in the orchard. It was an ordeal, to be sure.

First of all, the blades didn't cut so much as they stripped the grass off, and I'd sharpened these blades about as much as I could before installing them. Also, when the deck got loaded up with heavy grass and old grass mulch, it would kick the blades back, which made the whole deck shake violently until I raised the deck to clear the clot of grass (forgot to mention, FULL SKIRTS on this mower). Third, my Farmall has no draft control, so when the front goes up, the back goes down, and vice versa- no reliable height control for a decent cut. Even if I set the deck to a height that keeps it from shaking, the hydro bleeds down until the deck is on its skids again, and shaking like crazy from all the grass load.

The last event was the piece de resistance. I had just finished mowing half the orchard, when I hit a particularly tall patch of grass and thatch. The mower started slamming into it, and before I could raise the deck, the bolts in the overload clutch sheared off, leaving the PTO spinning in its socket but not turning the gearbox. I shut the PTO off and raised the deck, and hauled the whole sorry mess back to the yard.

At this point, I think I'm just going to ask around to see if anyone needs an old stalk chopper for not too much. The welder up the road can make the other pair of blades, and there's an IH dealer near the reseller who might be able to source the shoulder bolts. We can pick up a used mowing deck (for ACTUAL MOWING) for around $500, because this thing is obviously not going to be able to do what I need it to do.

Nick

art · May 18, 2009

Art's Way made a lot of the old International shredders.

n9viw · May 18, 2009

Thanks for that little tidbit, I'll tuck that into my hat. Art's Way? Never heard of it, but that's nothing new.

I've since had the deck out a few more times. What I referred to as 'draft control' I actually meant 'position control', such as on my father's Massey Fergusen, which keeps the relative position of the 3-point reasonably level regardless of the pitch of the tractor. Quite handy in uneven terrain, wish I had it. Second, I found that the reason the rear didn't go up with the front was that the top link was in the wrong hole- this is what you get for not asking questions.

Once that was straightened out, I got the whole works moving up and down just fine. The mower still sits too low, however, so I generally run the deck just off the skids and keep an eye on it so the blades don't dig in. I take the shredded grass as par for the course; it's just being used as a rough-cut mower, so I shouldn't expect a putting green finish. Apart from that, though, it seems to be working okay.

I plan to ask the welder to make me another pair of blades to supplement the old ones that are already in there, and the old-stock purveyor said that the local Case/IH dealer may be able to correctly identify the deck and order parts for it, good for getting those shoulder bolts. Mowing should go more smoothly with all blades running.

High spots in the ground, or any imperfection over the level of the grass (stumps, etc) are still shaved off, but I'm thinking of adding a pair of 6" pneumatic casters to the front of the deck so I can set the level and not worry about digging the skids in.

Nick