NH 5070 Hayliner has hay that builds up on bottom of chamber

 I have a NH 5070 Hayliner that after baling 200-300 bales hay will start to build up on bottom of bale chamber at the first wedge on outside of bale chamber. You can tell that when baling with wagon behind baler the bales will start to get heavy.You will also notice hay will start to push out the top of bale chute. We stop baling have to clean the bale chamber out and you will notice a buildup of rye straw about 2 inches tall and entire width of outside rail.You can take your hands to clean out and it will be hot from friction and then we are good to go for another 200-400 bales. I make a 32 Inch bale that weighs around 45 to 50 lbs.  The baler does not have skiis and has only baled less than 15,000 bales and has done this from day one. I did not buy new, the previous owner baled 1000 bales and quit haying. Any ideas.   Thanks 

NH 5070 Hayliner has hay that builds up on bottom of chamber