Combines Rotor Vibration

I had that problem a few years ago and there was a pinhole at a weld that allowed dust in that caused it to go out of balance

Suggest you first engage the separator with the rotor out of gear to make sure it's the rotor which is giving you vibration. What model machine is this, and is it a grain or spec. rotorIJ

we had this problem a couple of years ago and ours was the hub at the back of the rotor. it has rubber bushings with bolts through them, i think 5, and 2 of our bolts were broke. they replaced the hub with an updated one.

I'm pretty sure that it is the the rotor because as you speed up or slow down the rotor the vibration changes. This is on 1680 w_spec rotor. JC

Set rotor in neutral and spin it several times. If it stops in the same location every time it may be out of balance but if it comes to reat in a different spot you probably have dust_dirt in it. Happened to me and had to cut an opening and clean it out. Hope this helps

Inspect the rotor bars first -- the front skirt(s) may be broken off one or more bars. Pull cover over the rear of the rotor and using an inspection mirror, check the bolts in the rear spline mount -- should be 6 of them, and with the rotor in gear, the spline mount shouldn't have any play if you try to move the rotor by hand. If this all looks OK, next thing is to clean the dirt from beneath all rotor bar mounts and again check balance. If vibration still begins at 800 RPM, impellers may have uneven wear, rear sweepers may have worn unevenly, bars may have worn unevenly or last, you may have some dust inside. You usually won't notice dust as it gathers, but after the rotor sets for some time, the dust tends to stick to one area due to condensation, etc. email if you'd like.