Combines 6620 cylinder concave questions

lay a n2 pencil in rasp bars and if pencil is above highest point replace them. JD gives a drill bit size, but can't remember at the moment. If he has more than 2500 hours on concave it needs replaced also.

Your observations 'may' be true. But there is alot more to look at while in there. Take a BIG prybar and see if the concaves go up and down with prying up. Maybe your egg shaped adjusters are wore out. Maybe it is tore out of left side. maybelots of things, better have somebody experienced with things look at it too. Make sure things are tight and level in there. IF It has any hours on since last checked there could have several problems all compunding one another!!!

Thanks, Turbo, for the tips on how to check the rasp bars. They were OK by that standard. Concave was not bellied, but would not close up all the way. It was easy to see after we pulled the feeder house off. just don nailed it; the link on the right had broken, one cotter pin had fell out that holds the cams in place, and the left cam dropped out of the levelling adjuster. It had worn down at least 3_4" in the side sheet. With the concave closed up, I could almost pass my hand between the cylinder and the concave at the second bar! Parts are ordered and will be here from Syracuse in the morning. Other issues on this old machine to deal with: several bad bearings, and a digital tach that wants to burn up the ground (white) wire if you plug it in while running. Oh well, never a dull moment! Oliver "Never wrestle with a pig; you both get all dirty, and the pig likes it."

When I bought my 6620 I pulled the concave out and blocked off the first 4 rows of openings from the bottom side and then took every other wire out behind those rows. Gives better threshing at slower speeds and better seperation, especialy in wet corn.

Thanks, Turbo. We've got it all together, and he'll be in high moisture corn next week. If he has trouble, I'l let him know of your recommendation about the concave. For now, I think he'll go with what he has.Oliver