Re: 2188 Shoe drive
These combines were built with too tight of tolerances in many places in the cleaning system. There are about a half-dozen places internally where the chaffer rails, auger bed, shoe frame, and rear axle all make contact. (bad.) Heartland Welding from North Dakota has a kit to fix all of this.
Also check your shaker slip clutch behind the big pulley to make sure the dogs aren't wore. That will cause some nasty pounding.
Also important to have your shaker arms and chaffer rails and frame square. Your dealer has a special new tool to properly square and align your shaker arms.
And another thing I remembered is make sure the dinky little washer and snaprings behind the big pulley aren't broke, usually caused by over tightening the big slipclutch coil spring. When that little washer breaks, it then squeezes the sides of your machine together, that could be your biggest problem.