Combines gleaner M header vibration

Do you disable the variable speed per the op manualIJ Tom in MN

I would also check sickle timing an stabilizer under cuting bar.

We have an l2 (24 Ft) and an M 22 (ft) headers. I have replaced the bellcrank and pitman arm and ball joint on bellcrank in both of them in the past. Some tips I have on it are checking for work guards and sickle sections. Use Used motor oil on the sections to reduce drag. Sometimes worn sickle sections and guards will make it drive hard. Good luck!