[Bearcat]

I have an 8780xp with the manual concave adjustment. I am currently combining flax and when I hit a slug or hear the rotor rumble the concave adjustment gear jumps the worm gear and then the concave opens up. I can't seem to get it to stop. Concave clearance is set to 1/8". The worm gear and concave gear are now starting to show wear due to the jumping. Just can't figure out how it jumps as when mated the gears are tight. If anyone has any advice I would appreciate it. Its making harvest frustrating

 

[narkstar]

Is your concave still giving you trouble?

Dad plugged last night and for the first time it has happened on my 2001 8780XP.

Will be keeping an eye on it. Some part must be flexing enough to allow the jumping.

 

[SK Farmer]

my 8570 did the same thing I replaced the whole adjusting system solved it. looked at parts when I took them out couldn't see any damage but the teeth must'n been sharp enough. hope this helps

 

[narkstar]

Unplugged this morning, and it was just one big wad right a the front. Must have been enough pressure that it pushed it wide open. Teeth were right on top of each other, and i had to hit it from the side with a shaft to get them to align and drop into place.

Hope this doesnt start happening every time it plugs (we only plug once a year anyway) or i may be looking at replacing a couple of parts.

 

[jon]

We've replaced both parts on an 8780, the worm and the notched part. Worm was thin and the notched was starting to round. Started dropping when thrashing wheat. Once changed never happened again. It's not that bad of a job to do.