Combines nuts on front rotor bearing coming loose

I had the same thing on a 2188. I just took them out and put loc tight on new bolts, and have never had another problem, and that was about 3 years ago. I have learned on these combines ,when you take something apart and replace your parts, put loc tight on every bolt you can. at least for me it has saved me some grief.

To check source of vibration, I'd suggest first operating the separator with the rotor out of gear. If you have vibration, it's likely the chopper. Suggest that you also loosen the peripheral drive belt idler (drives chopper and shoe) on the R_H side of the machine and re-engage the rotor to check for vibration there, as well. Have the bolt holes in the crossmember become oval from the vibration and operating while bolts were looseIJ If so, it's likely that you won't quite achieve proper alignment again and probably need to replace the crossmember. Although the bearing floats in the flange, it's still critical that centering is as close as possible. Hope this makes some sense.

Thanks for the replies, the one positive thing is with the sensor of the shaft we picked up on it quickly. I will likely check the chopper belt alignment as well as the rotor itself ( and locktite) dependant on time we may pull the front end apart and look at the bearing though it wasn't hot. One thing we've learned after close to 25 years of running these red rotaries is if somethings coming loose there's a reason.