the shoe on my reciprocating saw wobbles side to side a lot, makes cutting straight impossible

Diagnosis

The lateral wobble in the shoe of the Milwaukee M18 Fuel Reciprocating Saw (Model 2821-20) is typically caused by excessive play in the pivot assembly or a failure of the shoe's mounting hardware. Because this tool is designed for heavy demolition, the shoe (the metal guard that rests against the workpiece) takes significant lateral force. Over time, the pivot bolt can vibrate loose, or the internal bushing that centers the shoe on the gear housing can wear down, creating a gap. When the shoe wobbles, it fails to provide a stable fulcrum for the blade. This results in "blade wander," where the blade deflects sideways during the stroke, making it impossible to maintain a perpendicular cut. You can confirm this by grasping the shoe firmly and attempting to wiggle it side-to-side while the tool is off; any movement exceeding 1-2mm of play is considered excessive and will compromise your cutting accuracy.

How to Fix It

To eliminate the wobble and restore stability to your 2821-20, follow these precise steps:

1. Remove the battery pack to ensure the tool cannot accidentally trigger during the repair.
2. Locate the shoe adjustment bolt, which is the large hexagonal bolt passing through the center of the shoe assembly.
3. Using a 13mm socket or wrench, loosen the bolt slightly to allow the shoe to seat properly against the housing.
4. Push the shoe firmly upward and backward against the tool's chassis to remove any air gaps or debris trapped in the pivot point.
5. While maintaining this pressure, tighten the bolt firmly. Do not over-torque to the point of stripping the threads, but ensure it is snug enough to stop the lateral shifting.
6. Test the movement: The shoe should still pivot up and down to allow you to clamp the tool to the material, but it should not shift left or right.
7. If you find the bolt keeps loosening during use, apply a small drop of medium-strength blue thread-locking compound (such as Loctite 242) to the bolt threads before final tightening.

If That Didn't Work

• Replace the Shoe Assembly: If the bolt is tight but the wobble persists, the pivot bushing inside the shoe has likely worn oval. Since the bushing is integrated, you must replace the entire shoe assembly. Order the official Milwaukee replacement part for the 2821-20 shoe and swap it out using the 13mm bolt.
• Inspect the Blade Shank: Sometimes the "wobble" is actually the blade vibrating within the chuck. Ensure you are using a high-quality Milwaukee Torch or Steel-Cut blade. Check if the blade is fully seated in the chuck; if the blade is loose, the shoe will appear to shake during the reciprocating stroke.
• Check for Housing Deformation: Inspect the metal casting of the tool's nose. If the tool was dropped or used to pry heavy debris, the mounting point for the shoe may be bent. If the housing is warped, the shoe will never sit flush, and you may need a professional chassis replacement.
• Shim the Pivot: As a temporary field fix, you can wrap a thin piece of steel shim stock or a heavy-duty washer around the pivot bolt before tightening. This fills the gap created by wear and restores the tight fit required for straight cuts.

Heads Up

• Always ensure the shoe is pressed firmly against the material before starting a cut; if the shoe is hovering, the blade will vibrate violently, accelerating wear on the pivot bushing.
• Avoid using the shoe as a pry bar to lift heavy materials, as this puts lateral stress on the pivot bolt and can bend the mounting bracket.
• Periodically clear sawdust and metal shavings from the pivot area using compressed air, as debris buildup can prevent the shoe from seating flush and cause an artificial "wobble."
• Check the tightness of the shoe bolt every 20-30 hours of heavy use, as the high-frequency vibration of the Fuel motor can naturally back out the hardware.