[hflyboy]

The service manual for my F2 specifies that the number 2 concave bar be used to check for cylinder leveling and clearance; however, the cylinder on my F2 makes contact with some other bar (3, 4, or 5) while indicating about 1/4" clearance on bar number 2. Is this a common problem, and is there a way to adjust the cylinder position so that it contacts the number 2 bar prior to any other? Any help is appreciated!

 

[gleanerman]

Have you dropped the concave down and visually inspected it? I would check it for a bent bar farther back or maybe something lodged in it. Check for excessive wear, the front bars wear fastest. If it has high hours maybe its just plain wore out...

 

[hflyboy]

Thanks for the suggestion; the #2 bar is new and none of the others are noticably bent. The threshing chamber is clean. I'll check the other bars with a straight edge....I appreciate the suggestion that one of the bars could be bent, although they did not appear to be bent just eye balling them....

 

[okiefarmer]

Are you saying indicator shows 1/4" clearance or you have actually measured that amount of clearance? You may have already done this but drop rock trap door and turn cylinder till a cylinder bar lines up over the first bar(not counting the one on the door) lower cylinder until it contacts concave bar then set indicators to 0.
What year is your F2? I have a 77 model that we have ran for several years. Can't go very fast but is a very dependable machine. I basically totally rebuilt it last winter.Will try to poast some pics after harvest.

 

[ru4gleaner2]

Yep you need to zero out your concaves just like okiefarmer described. We zero ours out before each season then still drop the trap door and check with a 5/16 inch bolt. We'll slide that bolt across the bars to make sure their level. We've always ran our coventionals with about a 5/16 inch gap. Just need to hear a little growl.

 

[hflyboy]

The procedure described by Okie is the one I used; however, while turning the cylinder it contacts a bar other than #2 first. The cylinder comes to a complete halt while a measurable 1/4 inch gap remains between the cylinder bar and #2 concave. The cylinder bars are touching either 3, 4, or 5 before the cylinder can be fully lowered onto #2.

 

[hflyboy]

Addendum to my most recent post: My machine is a 1977 F2, Serial 37868 Corn/soybean special. I used it this week (first time!) to harvest wheat and oats, and planning to harvest soybeans this fall. Using a bolt to check level is a great suggestion...I backlit the cylinder and peeked in thru the feeder beater opening; this only works while the grain platform is off.

 

[okiefarmer]

Next step for me would be to remove the two bolts that hold door for concave bars and fold door down and see what you have. Must be something stuck in a concave bar or a bent door. There is not any adjustment that I know of that would prevent this from happening. However mine is not a corn, soybean machine and they could be different.

 

[hflyboy]

Okie, I've had the door down a couple of times, there is nothing stuck in there, and if it is bent it is a rather subtle type of bend...no obvious dents. I won't have a chance to look at it again until June 23, and I'll make it a point to evaluate the profile of the concave with a straight edge and something approximating the curvature of the cylinder to see where the high spot is. That door is robust...I don't know how it might get bent in a way that would cause a "high" concave bar; maybe sombody put a floor jack under it in the machine's previous life!? I'd love to see pics of your F2.

 

[gleanerman]

hiflyboy...what type of concave bars are installed on your concave, rasp, U channel , 1/2 round, or a combination of all three? There were times when we were running "G"'s that we had to shim up certain bars with flat stock to get the required clearences, not that hard to do.. as others have mentioned I don't know of any adjustments to correct the condition you describe. We ran our cylinders with close to zero clearance with a U channel on the door, a rasp bar in the second position, U channels behind that and a half round at the very back. We made our own U channel bars with stock from the local metal supplier, much cheaper than Agco, especially when equipping ten machines... We combined wheat, barley, canola, flax,peas , soybeans and alfalfa with this setup...

 

[hflyboy]

I'm running AGCO U-channel concaves. I had 5 in there for wheat, 3 for oats. I'm intrigued by the variety of bars you used. Shimming up the bars to a consistent height might solve the problem; I just have to determine a way to determine the proper amount. My next project will be to set it up for soybeans; this is my first combine, the learning curve is pretty steep right now.

 

[hubes]

When I check the clearance one my f2. I have 1/4, 3/8, 1/2, and 5/8 pieces of wood I keep in the tool box. About 4" long by 3" wide to slide between the cylinder and concave bar. Just another suggestion for checking clearance. I also use them for setting sieve and chaffer.

 

[hflyboy]

Great suggestion! Thanks, Hubes. Have you ever had the cylinder bar contact concave 3 or 5 while still having 1/4" clearance on concave 2?

 

[gleanerman]

highflyboy.......This topic reminds me of as statement by a wise old mechanic many years ago, he was fond of saying " just because it was made in a factory don't assume it was made right"... I have found this to be true on several occasions. Maybe your concave was never right from the start.. about all you can do now is shim the bars to the right height.

 

[hubes]

hflyboy,
i've never had that problem. sorry i can't help you there.

 

[hflyboy]

I finally got a chance to investigate further....I put masking tape on concave bars 3 and 5 and lowered the cylinder until I got good solid contact. After lowering the concave, I discovered that the cylinder contacts both bars 3 and 5 simultaneously, and while #2 still has about 1/4" clearance! I had good solid witness marks on both. It appears that the #2 bar is lower, although everything is straight, solid, and properly bolted up. I wire brushed all the mating surfaces to make sure the concave wasn't being held off the thresher housing by rust and dirt. My plan is to shim up the #2 bar to match the height of 3 and 5. Thanks to all for the great suggestions!