I have a 500A that has been a good grinder.

We never ground 4 ton loads of hog feed with ours.   Unless you had really heavy corn and minimal other low density ingredients in the mix it would usually pop the lid open around 7800-7900 lbs.

We always did 7000 lb loads and that way it should have done a better job mixing.  Around 7300-7500 is where it usually would quit mixing.


 Couple things to check are the worm/ring gears that lift the unloading auger.  Check see if that oil cup has evidence of having oil in it.   If that cup isn't kept full of oil it doesn't take long to take the bearings out on the worm gear shaft.  Once the bearings go out it doesn't take very long at all to chew up the worm and ring gears.     Also check out the gears that drive the unloading auger.  Look for evidence of them being lubed.   I always liked to put gun grease on them as often as possible, the covers on the top 2 pairs of gears were basically full of grease.  It was messy but it kept those gears quiet.  The bottom set of gears didn't have anything to hold grease by them so on those I would regularly spray with Justice Brothers chain lube.

Another place to check is the 60 chain and sprockets that drive the mixer.   This chain is right behind the big belt pulley that drives the feed mill.  The 1000 pto mills have a little 13t sprocket that has a tendency to wear quickly if the chain is not kept in very good condition.  To keep that chain in good condition you need to lube it regularly and replace it often.     The newer Arts-Way grinder/mixers moved this chain to the back side of the mill and used a double 60 chain that lasts much longer and doesn't chew up the sprocket near as much either.
I actually changed mine to the double chain setup behind the mill like the newer ones have.  I don't remember all of the details of doing so but for me it was well worth not having to mess with that chain all the time.


As I said our was/is a good machine.  The past few years it has been relegated to being our backup grinder only being used when our newer machine has problems.   In the near future it will probably be for sale.