Int. 650 Forage Harvester
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=128976
Printed Date: 21 Jun 2025 at 4:32am
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Topic: Int. 650 Forage Harvester
Posted By: Johnwilson_osf
Subject: Int. 650 Forage Harvester
Date Posted: 19 Sep 2016 at 7:42pm
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Greetings all, I am flummoxed, and hoping that someone can help me. My International 650 forage harvester (with 2-row corn head) is breaking shear pins. The shear pin is located where the main drive is for the gathering chains on the corn head. These chains are the only thing being driven by this drive line. I cannot find anything binding or catching. I did see that one of the sprockets that drives the lower gathering chains is missing two teeth (rust patterns tells me they have been broken for a while), but other than that I see no obvious things wrong. Bearings are tight, shafts have no play, chains are not catching, I am stumped. Anyone have any experience with these? Any advice? Thanks in advance. John ------------- Allis Express: Eastern PA on Rt 80 8050, 8010, 6080, 190, D14, DA 6035, AA 6690, 5650, Gleaner F2 |
Replies:
Posted By: Auntwayne
Date Posted: 19 Sep 2016 at 9:14pm
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What are you using for shear pins ?
------------- Dad always said," If you have one boy, you have a man. If you have two boys, you have two boys". "ALLIS EXPRESS" |
Posted By: Johnwilson_osf
Date Posted: 19 Sep 2016 at 9:38pm
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3/8 bolts 2.5 inches long.
------------- Allis Express: Eastern PA on Rt 80 8050, 8010, 6080, 190, D14, DA 6035, AA 6690, 5650, Gleaner F2 |
Posted By: Allis dave
Date Posted: 20 Sep 2016 at 6:48am
| Are you able to turn the shaft by hand with the shear bolt out to see if it's hanging up somewhere? |
Posted By: Lonn
Date Posted: 20 Sep 2016 at 6:52am
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Are you sue the broken sprocket isn't the problem? ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: shameless (ne)
Date Posted: 20 Sep 2016 at 7:17am
| open up the throat a little more, (widen it) sounds like it is getting to much in and thus shearing the bolts. |
Posted By: jiminnd
Date Posted: 20 Sep 2016 at 7:27am
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I would think when you get up to speed that broken sprocket would be the trouble. ------------- 1945 C, 1949 WF and WD, 1981 185, 1982 8030, unknown D14(nonrunner) |
Posted By: Tbone95
Date Posted: 20 Sep 2016 at 7:52am
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Breaking while chopping, or just running? I'd agree, a broken sprocket isn't helping at all.....and/or, did the teeth on the sprocket break because something is binding/catching and a tooth snapped off rather than a shear bolt. If it's breaking while chopping, the wear in the gathering chain system can cause trouble. Meaning, are all the sprockets in good shape and not worn down in diameter. Are the chains in good shape or all loosened up. Can the tensioner keep good tension on the chain. Does the chain "float upwards" because it's loose and corn builds up under the chain in the channel. |
Posted By: caledonian
Date Posted: 20 Sep 2016 at 2:50pm
| I'd say if you replace the sprocket with new you might solve your problem. Make sure your gathering chains aren't so worn that they are jumping the sprocket . If that's the case replace. |
Posted By: Johnwilson_osf
Date Posted: 20 Sep 2016 at 6:25pm
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Thanks for the input everyone. Chains are as snug as recommended in the book. When I replace the shear pins, I can turn the shaft by hand, and do not experience any binding. As soon as I turn on the PTO, I make about a minute of time before the shear pin breaks. This is just sitting in the yard, not even under load. This is where it is weird. I don't feel any binding when turning by hand, but the machine obviously does somewhere, else it wouldn't break. I have a parts machine in the back to scavenge from, so I can replace the sprocket, however based on the rust on the teeth, I can only assume that has been that way for many seasons. Not saying that it isn't the problem, but it doesn't seem enough to bind. I managed to get a neighbor to help finish the field so I can get the silage finished, and then I have another winter project to work on to repair this thing. ------------- Allis Express: Eastern PA on Rt 80 8050, 8010, 6080, 190, D14, DA 6035, AA 6690, 5650, Gleaner F2 |
Posted By: Tbone95
Date Posted: 21 Sep 2016 at 9:06am
| That is a head scratcher. When you turn it by hand, do you turn it far enough to pass the gathering chains all the way around once or twice? Just wondering if there's a link or 2 in there that are just iffy enough when it hits the missing teeth in the sprocket, that's when it binds. Or, I have lots of experience working on old choppers, but not this model, does this drive line also drive the feed rollers? Bad bearing or something in the rollers? Seems like a bit more of a long shot. |
Posted By: Allis dave
Date Posted: 21 Sep 2016 at 9:32am
| I was wondering the same thing, Is a bearing going bad and seizing when it heats up a little? |
Posted By: shameless (ne)
Date Posted: 21 Sep 2016 at 9:40am
| you don't have a 1/2 link in the chain that's causing it to lock on that broke sprocket? |
Posted By: JC-WI
Date Posted: 21 Sep 2016 at 10:02am
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Seems he was chopping and then started having troubles to the point of having it break right in the yard. Is that right JohnWilson? What did you do to the chopper before this started happening?? Take a link out of a chain? Does it go BANG when this happens or .... ... or Are you putting in some butter bolts? Is this shear pin location a shaft inside a hub or a flange against a hub or sprocket? Are the shafts sloppy between the inner shaft and the outter parts with lots of slop? not tightening enough or tightening to much? Does it look like this one?   &  Like mentioned above, turn it for many revolutions till you have the chain go aropund for awhile and know its not jumping teeth /sprockets or bearings. When under tension and the pin goes, it could spring bang back several revolutions. Check for bent shafts and bad bearings and get that broken sprocket replaced.+- maybe find the real cause while replacing it. Good luck. ------------- He who says there is no evil has already deceived himself The truth is the truth, sugar coated or not. Trawler II says, "Remember that." |
Posted By: Tcmtech
Date Posted: 21 Sep 2016 at 10:21am
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Run it empty while watching it closely. When whatever binds up hard rough to shear the pin you will likely see a momentary stall or hard load up on that component and what it's catching on. I had a round baler locking up and breaking chains issue a while back that drove me nuts trying to find. It turned out that one sprocket on a shaft was loose and floating side to side. When it got far enough over it's related chain would rub another that ran the opposite direction at a different angle and once the two connector links got lined up on each other, quite a few revolutions for them to do so that was the key, they would catch on each other and lock things up or tear one of the chains in half.
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Posted By: JohnCO
Date Posted: 21 Sep 2016 at 10:40am
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Lots of good advice here. My only suggestion is make sure you are using the correct shear bolt, probably grade 5 but maybe IHC had something harder for this machine. Good luck!
------------- "If at first you don't succeed, get a bigger hammer" Allis Express participant |
Posted By: Johnwilson_osf
Date Posted: 21 Sep 2016 at 11:16am
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All, Thanks for the great advice. Tbone: "When you turn it by hand, do you turn it far enough to pass the gathering chains all the way around once or twice? Just wondering if there's a link or 2 in there that are just iffy enough when it hits the missing teeth in the sprocket, that's when it binds." I can turn it by hand around and around for many revolutions of the gathering chain system. All the chains are snugged to the manual specifications. Shameless: There are no half-links. Tbone: " does this drive line also drive the feed rollers?" The driveline for the feed rollers and chooper mechanism is separate from this shaft and shear pin. The only items run by this shaft are the gathering chains on the head. Allis Dave: All the bearings are in good condition. They have no noticeable slop in them when grabbing pulleys, or shafts. I may see something different when I take it apart. JC(WI) We broke a shear pin when we pulled a branch into the pickup, jamming the chains and the knives. Had to replace the sickle. Since then, we are breaking shear pins. Now, like said above, I can turn it by hand, and run the chains all day long. But when I run it at low idle on the PTO, It can turn for 5 minutes or 5 seconds before it breaks a shear pin....but it always breaks. The machine distinctly goes bang when the bolt breaks. I am using just simple machine bolts for the shear pins. The shear pins are located on a shaft coupler. The shaft has a dog eared, spring loaded coupler on the machine side, and a dog eared pined coupler on the gathering chain side. It is just barely in view in front of the gear box on the third picture you posted. I will see if I can get a photo for people tonight. All shafts are tight. TcmTech: I have watched individual components for 10 shear pins, and nothing moves or jumps, or changes when the pin breaks. I think JC is right, that I might find the problem when I replace the sprocket JohnCO: I will call the local dealer today to verify the bolt type. Thanks to everyone. Will keep you posted. John ------------- Allis Express: Eastern PA on Rt 80 8050, 8010, 6080, 190, D14, DA 6035, AA 6690, 5650, Gleaner F2 |
Posted By: Tcmtech
Date Posted: 21 Sep 2016 at 11:34am
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That just seems very odd. The only thing I can think of that would allow it to break a pin that fast without any observable system bind would indicate the problem is very close to where the shear pin is located and on a major component of the drivetrain itself that has no torsional or tensional give. Can individual sub drive assemblies be disconnected and be ran one at a time without affecting timing of anything? Disconnect everything then run with nothing but open shafts and if the pin stays put then add one sub assembly drive at time until it goes bang? Process of elimination of sorts. |
Posted By: wfmurray
Date Posted: 21 Sep 2016 at 12:02pm
| Dad was helping a neighor once and had same troble .Chains must be same length and same no of links between dogs. Need good sprockets.If you have an extra link one chain will gain on other and the dogs will evently run togather and break something. |
Posted By: Tbone95
Date Posted: 21 Sep 2016 at 12:28pm
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Huh! Well, you're doing good, you got us stumped form our arm chairs! What he said above, ya, see if you can take a chain or pin or something off to only operate 1 row, that should tell you which row is giving you grief. |