Combines Material Buildup in Feeder

check to see if the sprockets on the pivot shaft have shifted. Should be equal distance RH and lH from slats to sidewall. IF the chain sags more on one side than the other the chain could have some wear. Do you have solid drum or sprockets and floating shieldsIJ I should have ask that question first I suppose. The other reason could be the shearing or back feeding due to the back feed chain not stripping the material from the front. Check to see differences between ft, back and side to side here as well. Finally the rear feed chain front stops could be damaged causing this as well.

I'm sure R40s are the same as R50s. On the R50s we have had to fill in the area behind tube to just clear sprocket by approx 1_4". This tube was allway close to sprockets prior and effective the R50s. We just laid a 2"X4" piece of steel tube behind square tube and welded on top. This will prevent the buildup in that area which will cause wrapping. Also get good look at floor to be sure your floor isn't wearing threw causing poor flow. I think it is the condition of straw causing the jumping and wrapping but these conditions are likely not going to get better as the years go on. I believe loewen would have feeder shocks for that model and be sure to get a flattened rear floor when replacing it. This will all get that tough straw to flow smoothly. Good luck