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case 1680 concave bar always pulls out?????

6509 Views 14 Replies 9 Participants Last post by  2388h
i have a case 1680 that the concave bar on the right side always pulls out of the holder then the concaves drops down onto the augers. it is the solid steel shaft and still does it. i have the speacialty rotor if that makes a difference. was there an update kit for this type of issue or do i just have to weld it in solid? thanks for any info regarding this problem.
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Rotor type makes no difference.

In order for that bar to fall, it would have to also break or pull out, those eye bolts that go upward toward a heavy bracket that goes from the front cone support to the center cage support.

Perhaps someone removed this bracket and did not re-install it?

I no longer have that support and hardware in my machine as I have made a modfication there. However I do still have the bracketry, perhaps even the eye bolts, not sure.

Here's a picture of a parts list for the support. This is from Case IH 's parts online site, so they are to be credited for it. I simply put the arrows on it for clearification.

The support "#4", may still be there, but someone may have removed the straps, "#7". ?? Anyway, this setup must be in working order. Welding the solid round to the end brackets will not solve your problem.
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I had the same problem in my 1680 last fall. I suspect that the bracket that holds the rotor cage to the side of the combine may be bent. I tried a few things like welding stops on the bar etc and it still did it. Maybe take a measurement between the brackets that hold the bar in place and compare that to the specs. I have my combine booked in for a rotor change and some other work this spring so I'm going to have the dealer take a look at this problem then.
the right eye bolts and everything are there. the time it fell onto the augers the eybolts broke. i since then put in new eye bolts and brackets and even welded it to the front bracket in a few small spots and it just pulls itself out of the bracket but does not able to fall all the way down. i just bought this combine last fall and only had a chance to put on 100 hours maybe. i will be looking onto this alot further this summer but just wanted to see if anyone else had this trouble
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That's exactly how mine looked. I tried welding key stock on the bar to stop it from moving too far back and forth but it didn't seem to stop it from coming out. I had it go down on the augers a couple of times, breaking the eye bolts. I took a measurement between the brackets and compared it to my 1482. The 1680 space was wider, can't remember how much. I think either the rotor cage bracket is warped where the rear bracket mounts or both brackets are bent or worn. It could be a combination of all these things. Please post what you find out. As I said before, I have mine going in for some work this spring so I will have the dealer check this out.
Any chance you can get some more pictures of the area and drop the concaves down so one can look at the transition area? From the left side would be fine.

In a basic sense, the rotor is a large bolt and the cage, grates and concaves are the nut. The bolt is constantly trying to screw itself out of the nut when material enters the machine. This means the concaves are being pushed rearward as well as trying to be pulled around the rotor.

To walk the support bar rearward like that, IMO, needs some sort of cycle. Like a harmonic cycle of sorts.
We have a 1666 but had similar problem. The top bar that pulls down to the concave to was not seating to the concave correctly. The same with the bottom bar, the concave didnt seat correctly there either.

We got the concave to seat right by grinding it down until it was desirable. Both top and bottom. So that way both the top and bottom bar seated nicely to the cancave when the I-bolts were tightened, holding the concave in place to never fall out again!!!!!

Check it out it
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Mine popped out for the second time in 400 acres. The first time the clamps had broken, they were welded up and put back together. I had 15 acres left when the sample went to ****, I checked and the concave was down again. Snow forecast for the next day and the auger was already screwed so I finished up like that.
I have to change the auger in the spring but I sure don't want this to drop again. I will check the seating of the concave on the bar (new harvest services concave before I bought it 400 acres ago). Is there any other way for this thing to jump off? The clamps aren't broken and nothing looks bent.
Never did figure out exactly what the problem was with mine. I had the rotor replaced and the solid bars were replaced along with new concaves and new brackets I think. Hasn't given me any problems since.
Ouch, okay I will replace the brackets and bar when I fix it next summer. I'll also check that the concave saddle is deep enough, maybe open it up a bit just in case. Thanks
Just realized I never shared what fixed it. The harvest concave is a bit to thick at the saddle, it wont let you remove the concave in without loosening the bar from the front and rear bracket and having to readjust every time. The previous owner had ground the top of the concave tab off so it would slip in but that left the saddle so shallow it could pop out. I bought new concaves and saw the difference, it now doesn't pop out but it is a bear to change and readjust. I plan on grinding the tab next time the concaves are out but will grind the top of the saddle so the bar sits down into the saddle deeper as well. This will let the bar be solidly secured but let me remove the concave without screwing with the bar adjustment.
Hope this helps if anybody has the same problem (hopefully I'm the last guy to ever fight with this though:)
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I forgot about this thread as well, I also installed harvest concaves and haven't had a issue since then. there a way better built than the case concaves and even sit more even in the saddle part when tightened down.
Is this maybe a lesson, run case concaves and never any trouble. They have been running the same combine for all intensive purposes for 35 plus years, probably have it figured out. If wear is an issue have them chromed, we run nothing else.
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